Heat pump in New England

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Topic Author
indexfunds
Posts: 58
Joined: Fri Dec 28, 2018 11:13 pm

Heat pump in New England

Post by indexfunds »

Hello,

We are looking to replace our AC unit and are wondering if any of you who live in New England or other cold winter climates have experience with heat pumps. Our coldest month is 34/12 F (high/low). The hottest month is 82/58 F (high/low), although it's been in the 90s recently. We are looking at Lennox and Trane. Lennox has single, two-speed, and variable speed. We have an oil boiler for heat. Oil was $5.69 a gallon. Electricity cost is 19 cents per kWh.

Thanks
beardsicles
Posts: 65
Joined: Fri Nov 19, 2021 1:38 pm

Re: Heat pump in New England

Post by beardsicles »

We’re putting heat pumps in in Minnesota. I expect it’ll be $500-800 less to heat this year vs our natural gas boiler. They work well, but need backup heat here in MN. Don’t know how the math at 19 cents a kWh works out though, that’s almost double our cost of electricity.

Edit: lol, missed the oil boiler part. Put in heat pumps. You’ll save a fortune.
afan
Posts: 6952
Joined: Sun Jul 25, 2010 4:01 pm

Re: Heat pump in New England

Post by afan »

I have seen air source heat pumps be wholly inadequate in northeastern winters, not even New England. Ground source is much more expensive to install, but you should have no need of backup.
We don't know how to beat the market on a risk-adjusted basis, and we don't know anyone that does know either | --Swedroe | We assume that markets are efficient, that prices are right | --Fama
Topic Author
indexfunds
Posts: 58
Joined: Fri Dec 28, 2018 11:13 pm

Re: Heat pump in New England

Post by indexfunds »

Thank you.

One important consideration for us is what type of compressor: one-stage, two-stage, or variable speed. Would we even come close to recovering the initial costs and maintenance costs with the variable, over 15 to 20 years? We tend to run the AC at 77 in the summer and heat at 70 in the winter.
beardsicles
Posts: 65
Joined: Fri Nov 19, 2021 1:38 pm

Re: Heat pump in New England

Post by beardsicles »

afan wrote: Mon Jul 18, 2022 9:22 pm I have seen air source heat pumps be wholly inadequate in northeastern winters, not even New England. Ground source is much more expensive to install, but you should have no need of backup.
It completely depends on implementation. They work, and work well in Minnesota. You need a contractor who knows what they’re doing though and can design the system to meet your needs. Finding a contractor who will run actual load calculations is, unfortunately easier said than done.
suemarkp
Posts: 908
Joined: Sun Nov 12, 2017 8:18 pm
Location: Somewhere in WA State

Re: Heat pump in New England

Post by suemarkp »

Evaluate your electrical service for enough headroom to add the heat pump. If you have air conditioning now, the heat pump should be about the same load. However, they need backup heat in case the heat pump fails or can't keep up. You can choose whatever fuel you want -- oil, gas, electric resistance. Electric resistance would make the most sense but they can take a lot of power. You'd probably want at least 10KW of resistance heat (40 amps of load, 50A breaker), but size will vary based on heating load.

Look for a cold climate heat pump. The american companies are kind of getting in to these, but they are more typical from the asian manufacturers and especially the mini split manufacturers. These will still make decent heat down to 0 degrees F. A classic heat pump makes it rated heat output at 47F. As the outside gets cooler, the capacity diminishes. Classic ones could be down to half output when it is in the low 20's. A cold climate one should be 80% to 90% rated capacity at that temperature.

Finally, evaluate your duct system. Oil heat, especially old systems, is hot. Very hot air requires less air flow to heat a room. The heat pump is only going to make air that is about 90F to 100F so it needs to flow more air to put the same amount of heat in each room. So you may need larger or additional ducts installed. You may need to reduce your heat loss in order for a single heat pump to heat your house (e.g. new double pane low e glass windows, added insulation, etc). That can reduce the heat needed in each room so you don't need more air flow that what you have now. The HVAC contractor should perform a Manual J calculation to determine what size heating and cooling you need.

Once you can answer these questions, then some of your questions would be easier to answer (and cold climate heat pumps tend to use variable speed blowers and variable speed compressors).
Mark | Somewhere in WA State
ondarvr
Posts: 169
Joined: Tue Dec 22, 2020 6:03 pm

Re: Heat pump in New England

Post by ondarvr »

Old school equipment has limitations, new (for the US, but common in the rest of the world) variable speed inverter systems work very well even in sub zero weather.

My system heats my house at -10F without any backup heat source. There are several threads here on this subject.

Many contractors just install the same old equipment they've used for 40+ years and know very little about newer technology.
User avatar
whodidntante
Posts: 11003
Joined: Thu Jan 21, 2016 11:11 pm
Location: outside the echo chamber

Re: Heat pump in New England

Post by whodidntante »

I live in a place where the winters are measured in suicide rates. I don't know anyone who has a naked heat pump or would think that is a good idea. I do know one person who has a heat pump that is backed by a natural gas furnace for the really cold days, which are plenty. Granted, I don't know everyone. I also don't ask everyone I do know how they heat their homes.

Myself, I have a modern and huge natural gas furnace. People who live in the sticks sometimes burn those sticks to stay warm. I would be interested in a heat pump for cool weather. Probably right up until the point where I see the price tag. My air conditioning system can't even handle a 95-degree day without losing the fight completely, so I'm sure a successful heat pump would need to be much larger than what I have now.
asahopkins
Posts: 19
Joined: Sat Jul 26, 2014 11:44 am

Re: Heat pump in New England

Post by asahopkins »

OP has an oil boiler (radiators) so the duct system is scaled to the cooling load and airflow. So, one question is how well that duct system will do for heating. I think that with a variable speed HP, which can run constantly to deliver the right heat (which helps a LOT with comfort), the ducts will likely be fine.

Yes, go for variable speed and cold climate certified. You can find a database of cold climate products at https://ashp.neep.org/. If the Mitsubishi/Trane central ducted systems can work for you, I’d recommend them. (We have a small version of this for one of our zones; other zones are ductless.)

Get some good advice and/or hardware to coordinate the oil heat system with the HP so that when it is really cold the oil heat comes on to help. (Simplest approach is to set the oil heat thermostat to a couple degrees below the HP thermostat. When the HP can’t keep up any more and the temp inside starts to drop, the oil heat comes on.)

Worth taking this occasion to 1) insulate and air seal at least up to the level a few thousand dollars will buy you, maximizing what utility/state funding you can, and 2) having a real heat and cooling load calculation done (“Manual J”) so as not to pay for more capacity than you need.
Valuethinker
Posts: 45273
Joined: Fri May 11, 2007 11:07 am

Re: Heat pump in New England

Post by Valuethinker »

asahopkins wrote: Tue Jul 19, 2022 12:13 am
Worth taking this occasion to 1) insulate and air seal at least up to the level a few thousand dollars will buy you, maximizing what utility/state funding you can, and 2) having a real heat and cooling load calculation done (“Manual J”) so as not to pay for more capacity than you need.
It's probably worth reiterating the point often made here that the Manual J is as much about comfort as cost.

There's a tendency to oversize HVAC. But that can mean the system cycles on and off too much, reducing comfort.
Valuethinker
Posts: 45273
Joined: Fri May 11, 2007 11:07 am

Re: Heat pump in New England

Post by Valuethinker »

indexfunds wrote: Mon Jul 18, 2022 9:13 pm Hello,

We are looking to replace our AC unit and are wondering if any of you who live in New England or other cold winter climates have experience with heat pumps. Our coldest month is 34/12 F (high/low). The hottest month is 82/58 F (high/low), although it's been in the 90s recently. We are looking at Lennox and Trane. Lennox has single, two-speed, and variable speed. We have an oil boiler for heat. Oil was $5.69 a gallon. Electricity cost is 19 cents per kWh.

Thanks
If you search on poster talzara they seem to know a lot about Heat Pumps. Worth a read.

I am assuming that you used forced air to heat? Not rads? In the latter case, there are air-to-water heat pumps -- widely sold in Europe. They exist in Canada. I am not sure if there are any in the American market (where the origin of HPs was much more in southern-type climates for AC with limited heating need).

(When you said "oil boiler" that can mean, in American terminology, an "indirect" system where the burner heats hot water & hot water for rads on separate circuits? That's how UK houses are done - hot water heating (tap & rads) via the same burner. I gather it is much rarer in USA).

On backup. It depends how you feel about this. But it may be the opportunity to get rid of oil tank? The US situation seems to be, from what I can gather, that oil heating puts off some buyers (but perhaps not in New England where it is more common?). And an underground oil tank basically has to be removed & decontamination certified - very hard (impossible?) to sell a home without doing that. I must admit the thought of an oil spill soaking into the ground gives me jitters. And burning oil emits nasty pollutants (these days, hopefully in very small quantities) which in principle can get sucked back into the house (small risk).

The Coefficient of Performance of electric bar backup is by definition 1.0 (vs say 3.0-4.0 for the average HP running in average conditions ie 1kwhr of electricity moves/ provides 3 kwhr of heat, say). You can work out what your oil price translates to as price per BTU against that**. Oil furnaces (modern) have a COP of around 0.90 I believe (Furnace Efficiency is something that is labelled).

If you have ever considered solar PV this might be the moment to put that into effect? Because then running the HP in daytime could be virtually free?

** I can't look up the formulae right now. It's basically about converting kwhr of electricity (with efficiency of 100% ie COP 1.0) into BTUs of heat.
User avatar
stickman731
Posts: 375
Joined: Sun Jan 01, 2012 10:42 am
Location: New Jersey

Re: Heat pump in New England

Post by stickman731 »

This topic is covered a number of times over the years - here is one post with a lot of comments.

viewtopic.php?t=363815
RobLyons
Posts: 1515
Joined: Tue Oct 31, 2017 12:55 pm

Re: Heat pump in New England

Post by RobLyons »

I live in New England and have worked with Mass Saves and other contractors over the past several years on heating/cooling, going green, and whatever I can do best for my house while being as fiscally responsible as possible. For us, heat pumps just do not make financial sense. We saved the most money when we converted from oil to natural gas. Our entire winter heating bill went from ~$2k down to $566. A heat pump would be thousands if not $10k+ for very little savings.

If the numbers work for you, Mass Saves has 0% financing available as well as rebates up to $10k. Good luck!
"Great parenting sets the foundation for a better world"
Valuethinker
Posts: 45273
Joined: Fri May 11, 2007 11:07 am

Re: Heat pump in New England

Post by Valuethinker »

RobLyons wrote: Tue Jul 19, 2022 5:23 am I live in New England and have worked with Mass Saves and other contractors over the past several years on heating/cooling, going green, and whatever I can do best for my house while being as fiscally responsible as possible. For us, heat pumps just do not make financial sense. We saved the most money when we converted from oil to natural gas. Our entire winter heating bill went from ~$2k down to $566. A heat pump would be thousands if not $10k+ for very little savings.

If the numbers work for you, Mass Saves has 0% financing available as well as rebates up to $10k. Good luck!
I am guessing that just about everyone in New England who can switch to gas from oil has done so? As the likely payback is sub 4 years? The main problem in New England, as I understand it, is simply a lack of gas capacity-- both in transmission lines into the region, and local distribution.
cmr79
Posts: 169
Joined: Mon Dec 02, 2013 4:25 pm

Re: Heat pump in New England

Post by cmr79 »

An oil boiler with an efficiency of 85% will produce about 35 kWh of heat from one gallon of oil (converted from BTUs), so at $5.69 per gallon, the cost is about 16.3 cents/kWh of heating. In average NE January temps (obviously varies a lot by specific location) of 20F, and air-source heat pump is probably operating with a COP of around 2.0, so at electricity costs of 19 cents/kWh the cost is 9.5 per kWh of heat.

From a purely economic standpoint, it seems like whatever heat the heat pump produces will be 40% cheaper than oil at the coldest time of year, when the heat pump is the least efficiency. Whether that is worth the cost of installation for you will highly depend on the additive cost and shorter lifespan of heat pumps vs air conditioners and how much heating oil you use on a yearly basis.
matti
Posts: 280
Joined: Thu Mar 07, 2013 9:17 pm

Re: Heat pump in New England

Post by matti »

I live in northern MN and we put in a air-source heat pump last summer. Average January temps here are 20F (high), 4F (low). It can get to -20F pretty routinely, however. The pump can heat to about 35F or so, then our gas furnace kicks on. The cooling is pretty good, too.
RobLyons
Posts: 1515
Joined: Tue Oct 31, 2017 12:55 pm

Re: Heat pump in New England

Post by RobLyons »

Valuethinker wrote: Tue Jul 19, 2022 5:27 am
RobLyons wrote: Tue Jul 19, 2022 5:23 am I live in New England and have worked with Mass Saves and other contractors over the past several years on heating/cooling, going green, and whatever I can do best for my house while being as fiscally responsible as possible. For us, heat pumps just do not make financial sense. We saved the most money when we converted from oil to natural gas. Our entire winter heating bill went from ~$2k down to $566. A heat pump would be thousands if not $10k+ for very little savings.

If the numbers work for you, Mass Saves has 0% financing available as well as rebates up to $10k. Good luck!
I am guessing that just about everyone in New England who can switch to gas from oil has done so? As the likely payback is sub 4 years? The main problem in New England, as I understand it, is simply a lack of gas capacity-- both in transmission lines into the region, and local distribution.

According to the state website, it appears like half of New England is natural gas. 26% oil, 16% electricity. I don't have hard figures for those that specifically converted from oil to gas but I've been in many homes that still have oil heating. Mass is somewhat expensive to live in and the middle class that I know tend not to do big construction on their houses. I'm an outlier :sharebeer but I also waited until we had an issue with our oil tank to convert.
Years ago we were falsely informed that there was no gas line on our street and none of the neighbors were aware because they did not have natural gas.
"Great parenting sets the foundation for a better world"
Topic Author
indexfunds
Posts: 58
Joined: Fri Dec 28, 2018 11:13 pm

Re: Heat pump in New England

Post by indexfunds »

We have a high efficiency oil boiler that is connected to a central duct system with air handlers. The AC units are also connected to the air handlers. Unfortunately our region does not have natural gas. It's either delivered propane or oil. The oil tanks are not buried.
User avatar
Tubes
Posts: 1191
Joined: Wed Apr 22, 2020 6:33 am

Re: Heat pump in New England

Post by Tubes »

cmr79 wrote: Tue Jul 19, 2022 6:42 am From a purely economic standpoint, it seems like whatever heat the heat pump produces will be 40% cheaper than oil at the coldest time of year, when the heat pump is the least efficiency. Whether that is worth the cost of installation for you will highly depend on the additive cost and shorter lifespan of heat pumps vs air conditioners and how much heating oil you use on a yearly basis.
You forgot one thing. It will feel terrible.

I would never heat with only a heat pump in that climate. I have a heat pump here in the Southeast, and it provides an uncomfortable warmth -- unless I have the backup heat running, which for me is resistive electric. You also need to let the heat pump do its thing and not set back the temperature. Fortunately in my climate really cold days are few and far between, so it works well for me.

We're seeing a lot of the "heat pump up North" posts lately. I get it. Either people want to do good for carbon emissions, or they don't like the fuel oil prices. Heat pump heat is great when it is 45 to 65 outside. Below that, be aware of the comfort downside, and be willing to have a good backup/auxiliary source such as gas.
User avatar
just frank
Posts: 1505
Joined: Sun Nov 02, 2014 4:13 pm
Location: Philly Metro

Re: Heat pump in New England

Post by just frank »

I pulled out an oil boiler to put in a 4 ton single-speed ASHP in 2009, the last time oil got this high. I have plenty of experience. No regrets.

I live in the Philly burbs, which runs about 4°F warmer than Boston, for highs and lows every month of the year. In a 2300 sq ft house.

My house did not have central air or ducts, and only had a 100A breaker box, so the full project cost close to $12k (in 2009).

I also did a lot of air-sealing and insulation work to reduce my heating load by 50%, from terrible to slightly better than peer houses in the area.

You asked about the compressor speed. The issue is this... dehumidification in the summer. If the compressor is sized for real heat production in New England winter, it is 2-3X oversized for New England summer. A too large AC unit has no trouble keeping the place cool (you'd be fine to 130°F outside), but it will run for a few minutes, and then shut off for a long time. This will result in poor dehumidification.

I have a bit of this problem with my single speed (and more outdoor humidity than Boston ever gets). I compensate by swinging the temp extra low at night and sleeping under a blanket. And in a pinch I run a dehumidifier in my living space.

So, the two-speed compressor will run in High for heating and Low for AC. And overcomes this problem.

The other thing to look for is indoor air handler being variable speed.... more standard now but a definite get. This helps with dehumdification by running less air in AC (getting colder air), and also avoids the 'bang on' and 'bang off' of force air systems that people find annoying. The air slowly ramps up and down and is much less noticeable.

I am personally a fan of inverter tech on compressors bc they are much more efficient. The two speed systems actually just have a bypass valve to cut to power/load and actually does little to the efficient...its simple, almost dumb tech.

You can pencil out the operating cost. BC the HP runs less eff in colder weather, and calls the backup strips when its very cold, you get whacked for 50% of your heating bill from Jan 1 to Feb 15. My heat cost me 9,000 kWh per year, but half of that is in those six weeks. In your case, I'd assume 10,000kWh for a well designed and installed system. That would be $2500/year, and your January Electric Bill will be $1000. YMMV, but those are round numbers. As for my numbers... my assumption is your annual oil usage is 600 gals/year. Scale accordingly.

I think it makes sense to switch, even if oil drops to $3 gallon for the next 10 years. The cost-benefit will depend on compressor longevity. AC compressors last for decades bc they don't run that much. HP compressors are cranking for 1000's of hours per year... My first one lasted 6 years, was killed by a 'fluke' accident and cost $5k to replace. The second one is slightly more eff, and has been kicking it for 9 years. And they are zero maintenance... I just change the near HEPA filter on the air handler a few times a year.

Both cheapo 'Goodman' brand. Last time I checked, all the compressors for the different brands are made by the same contractor.

Also: there are tons of haters out there for heat pumps, bc there are a LOT of hack installers and bad installs. Shop carefully for contractors and seek someone that has experience and happy customers in your area.
Last edited by just frank on Tue Jul 19, 2022 7:36 am, edited 2 times in total.
jebmke
Posts: 17062
Joined: Thu Apr 05, 2007 2:44 pm
Location: Delmarva Peninsula

Re: Heat pump in New England

Post by jebmke »

matti wrote: Tue Jul 19, 2022 6:42 am I live in northern MN and we put in a air-source heat pump last summer. Average January temps here are 20F (high), 4F (low). It can get to -20F pretty routinely, however. The pump can heat to about 35F or so, then our gas furnace kicks on. The cooling is pretty good, too.
I live in mid-Atlantic. Our heat pump still pumps heat down to about 20 degrees, depending on how windy it is. Resistance heat almost never kicks in if outside air temp is above 25F. But our house is very tight and we don't allow the setback to go to far back. It is also programmed for a long recovery time so the resistance heat isn't as likely to kick in. In a pinch, we can override but rarely do.

I have a Misubishi mini-split in one room that has no backup heat and it has worked down into the low teens
When you discover that you are riding a dead horse, the best strategy is to dismount.
Jack FFR1846
Posts: 15322
Joined: Tue Dec 31, 2013 7:05 am
Location: 26 miles, 385 yards west of Copley Square

Re: Heat pump in New England

Post by Jack FFR1846 »

I would recommend you double check your total electric bill. I double checked mine recently and found it was higher than I thought. About 30 cents per kWHr. This is in Eastern Mass served by Eversource. I did see an article saying that our rates may go up something like 8% while heading a bit west, some are going up 10%. Those who have natural gas availability also have much higher cost than places like the mid west by a factor of 2 to 3.

While Minnesota might be a comparison temperature wise, it isn't from electric rate wise. We're strangled by existing, small natural gas lines that feed the electric plants and when the gas companies want to add a line along the same route as existing lines, signs grow in front of houses near the lines like they're orange barrels on Rt 81 in Pennsylvania. No new lines have been allowed. For similar reasons, oil refineries in the northeast don't have lines feeding them from the gulf, so tankers from the middle east feed us.

To the OP: I would speak with an HVAC contractor who is able to do various versions of heating. They can give you the best system for your own home and the reasons why it's the best. We have no natural gas availability on our street even though there's a large Tennessee Gas Line transfer station in our town. To me, it's a big city availability thing. My father in law in Worcester has natural gas. We used to have bottled propane but now are all oil like the majority of New England.

With fuel prices, I'm quite happy to see my several cord piles of split, stacked firewood ready to go. We have a wood/coal forced air furnace with an oil backup.
Bogle: Smart Beta is stupid
cmr79
Posts: 169
Joined: Mon Dec 02, 2013 4:25 pm

Re: Heat pump in New England

Post by cmr79 »

Tubes wrote: Tue Jul 19, 2022 7:23 am
cmr79 wrote: Tue Jul 19, 2022 6:42 am From a purely economic standpoint, it seems like whatever heat the heat pump produces will be 40% cheaper than oil at the coldest time of year, when the heat pump is the least efficiency. Whether that is worth the cost of installation for you will highly depend on the additive cost and shorter lifespan of heat pumps vs air conditioners and how much heating oil you use on a yearly basis.
You forgot one thing. It will feel terrible.

I would never heat with only a heat pump in that climate. I have a heat pump here in the Southeast, and it provides an uncomfortable warmth -- unless I have the backup heat running, which for me is resistive electric. You also need to let the heat pump do its thing and not set back the temperature. Fortunately in my climate really cold days are few and far between, so it works well for me.

We're seeing a lot of the "heat pump up North" posts lately. I get it. Either people want to do good for carbon emissions, or they don't like the fuel oil prices. Heat pump heat is great when it is 45 to 65 outside. Below that, be aware of the comfort downside, and be willing to have a good backup/auxiliary source such as gas.
I cannot tell the difference between heat produced by my heat pump and heat produced by my propane furnace. OP would almost certainly continue to use his oil boiler for backup heat, so the potential "unpleasantness" of standing next to a duct and noticing less-warm air blowing from it in very cold weather (say, when it is in defrost mode) won't be an issue for them.
jebmke
Posts: 17062
Joined: Thu Apr 05, 2007 2:44 pm
Location: Delmarva Peninsula

Re: Heat pump in New England

Post by jebmke »

cmr79 wrote: Tue Jul 19, 2022 7:39 am cannot tell the difference between heat produced by my heat pump and heat produced by my propane furnace. OP would almost certainly continue to use his oil boiler for backup heat, so the potential "unpleasantness" of standing next to a duct and noticing less-warm air blowing from it in very cold weather (say, when it is in defrost mode) won't be an issue for them.
I grew up in SE and lived in mid-Atlantic with older systems and leaky structures. "Uncomfortable heat" usually means a drafty house and/or an older single stage heat pump that blows warm a lot and then not. New systems in a tight structure are very comfortable.
When you discover that you are riding a dead horse, the best strategy is to dismount.
Topic Author
indexfunds
Posts: 58
Joined: Fri Dec 28, 2018 11:13 pm

Re: Heat pump in New England

Post by indexfunds »

I am working with a reputable HVAC company who uses Lennox for heat pumps. They offer several versions, will have to get the final prices.
User avatar
Tubes
Posts: 1191
Joined: Wed Apr 22, 2020 6:33 am

Re: Heat pump in New England

Post by Tubes »

jebmke wrote: Tue Jul 19, 2022 7:43 am
cmr79 wrote: Tue Jul 19, 2022 7:39 am cannot tell the difference between heat produced by my heat pump and heat produced by my propane furnace. OP would almost certainly continue to use his oil boiler for backup heat, so the potential "unpleasantness" of standing next to a duct and noticing less-warm air blowing from it in very cold weather (say, when it is in defrost mode) won't be an issue for them.
I grew up in SE and lived in mid-Atlantic with older systems and leaky structures. "Uncomfortable heat" usually means a drafty house and/or an older single stage heat pump that blows warm a lot and then not. New systems in a tight structure are very comfortable.
OK, I'll grant you that. A modern tight house could work very well with a heat pump. My 40 year old leaky house probably helps with the uncomfortable feeling.

I guess I'm knee-jerk replying to OP and others where I see "We have an old oil-fired boiler". When I see that, I think "old, leaky house." I could be wrong, it might be a new house with a Rich Thethewey installed brand new boiler.
cmr79
Posts: 169
Joined: Mon Dec 02, 2013 4:25 pm

Re: Heat pump in New England

Post by cmr79 »

Even in an old, drafty, leaky house, I would argue that the heating system capacity would be the problem (if not able to warm up the house adequately), not the type of heating system. It's just much more likely that a heat pump would be under-sized in very cold weather when the COP is lower. Again though, I don't think that the OP is replacing their oil boiler...just considering replacing the AC unit with a heat pump and wondering about whether the cost savings is worth it. Without knowing the marginal cost of the heat pump over an AC unit and the amount of heating oil used, I'm not sure we can answer the question in any more detail. I highly doubt that the OP would notice any difference in comfort.
jharkin
Posts: 3408
Joined: Mon Mar 28, 2016 7:14 am
Location: Boston suburbs

Re: Heat pump in New England

Post by jharkin »

afan wrote: Mon Jul 18, 2022 9:22 pm I have seen air source heat pumps be wholly inadequate in northeastern winters, not even New England. Ground source is much more expensive to install, but you should have no need of backup.
Not true at all. I don’t understand why every time these questions get asked, people who don’t live in cold states and don’t own heat pumps keep making this claim.

In northeast winters you need a cold climate heat pump. The Japanese brands are much better at this, such as Mitsubishi Hyper Heat and Fujitsu. They work at full capacity down to -15 F. Just needs to be sized properly for the heat load at those temps.

I have a Mitsubishi Hyper Heat outside Boston and it’s completely displaced propane for the zone it’s on, even down to zero. Only cost 10% more than a Trane /Carrier AC only system f similar efficiency.
Big Dog
Posts: 3444
Joined: Mon Sep 07, 2015 4:12 pm

Re: Heat pump in New England

Post by Big Dog »

Tubes wrote: Tue Jul 19, 2022 7:23 am
cmr79 wrote: Tue Jul 19, 2022 6:42 am From a purely economic standpoint, it seems like whatever heat the heat pump produces will be 40% cheaper than oil at the coldest time of year, when the heat pump is the least efficiency. Whether that is worth the cost of installation for you will highly depend on the additive cost and shorter lifespan of heat pumps vs air conditioners and how much heating oil you use on a yearly basis.
You forgot one thing. It will feel terrible.

I would never heat with only a heat pump in that climate. I have a heat pump here in the Southeast, and it provides an uncomfortable warmth -- unless I have the backup heat running, which for me is resistive electric. You also need to let the heat pump do its thing and not set back the temperature. Fortunately in my climate really cold days are few and far between, so it works well for me.

We're seeing a lot of the "heat pump up North" posts lately. I get it. Either people want to do good for carbon emissions, or they don't like the fuel oil prices. Heat pump heat is great when it is 45 to 65 outside. Below that, be aware of the comfort downside, and be willing to have a good backup/auxiliary source such as gas.
I don't get that. 72 degrees indoor air temp (or whatever setpoint your prefer) is 72 degrees. "Comfort" is a matter of air temp and humidity (Unless you like to park yourself under the register adn have hotter air blow over you.)

Yes, HP's are designed to maintain a constant temp, so setbacks take a long time to recover, i.e., not a good idea unless you will be gone for awhile.
User avatar
TomatoTomahto
Posts: 14276
Joined: Mon Apr 11, 2011 1:48 pm

Re: Heat pump in New England

Post by TomatoTomahto »

jharkin wrote: Tue Jul 19, 2022 9:15 am
afan wrote: Mon Jul 18, 2022 9:22 pm I have seen air source heat pumps be wholly inadequate in northeastern winters, not even New England. Ground source is much more expensive to install, but you should have no need of backup.
Not true at all. I don’t understand why every time these questions get asked, people who don’t live in cold states and don’t own heat pumps keep making this claim.

In northeast winters you need a cold climate heat pump. The Japanese brands are much better at this, such as Mitsubishi Hyper Heat and Fujitsu. They work at full capacity down to -15 F. Just needs to be sized properly for the heat load at those temps.

I have a Mitsubishi Hyper Heat outside Boston and it’s completely displaced propane for the zone it’s on, even down to zero. Only cost 10% more than a Trane /Carrier AC only system f similar efficiency.
Ditto. Our house is heated via geothermal, but our fully detached garage/gym/office is heated and cooled by a Fujitsu ASHP. No problems keeping up with the Boston winter, and the particular building isn’t even all that well insulated. We decommissioned the oil burner and tanks.
I get the FI part but not the RE part of FIRE.
User avatar
Tubes
Posts: 1191
Joined: Wed Apr 22, 2020 6:33 am

Re: Heat pump in New England

Post by Tubes »

jharkin wrote: Tue Jul 19, 2022 9:15 am
afan wrote: Mon Jul 18, 2022 9:22 pm I have seen air source heat pumps be wholly inadequate in northeastern winters, not even New England. Ground source is much more expensive to install, but you should have no need of backup.
Not true at all. I don’t understand why every time these questions get asked, people who don’t live in cold states and don’t own heat pumps keep making this claim.

In northeast winters you need a cold climate heat pump. The Japanese brands are much better at this, such as Mitsubishi Hyper Heat and Fujitsu. They work at full capacity down to -15 F. Just needs to be sized properly for the heat load at those temps.

I have a Mitsubishi Hyper Heat outside Boston and it’s completely displaced propane for the zone it’s on, even down to zero. Only cost 10% more than a Trane /Carrier AC only system f similar efficiency.
Point taken. I will go back to my backwater southern hole. (Just kidding, I'm joking, relax.)

Seriously, I will take myself out of further conversations since I'm no expert on what you say. Please keep preaching to people who bring this up, however, because salespeople will sell anything. Preach the gospel of cold climate specialties because that's not what is always sold.
Topic Author
indexfunds
Posts: 58
Joined: Fri Dec 28, 2018 11:13 pm

Re: Heat pump in New England

Post by indexfunds »

Geothermal would be out of the question for us due to price. We have a high efficiency oil boiler and do not plan on replacing it soon. Maybe in the future, we will convert to propane. Looks like the HVAC company is only offering Lennox right now.
Big Dog
Posts: 3444
Joined: Mon Sep 07, 2015 4:12 pm

Re: Heat pump in New England

Post by Big Dog »

indexfunds wrote: Tue Jul 19, 2022 10:05 am Geothermal would be out of the question for us due to price. We have a high efficiency oil boiler and do not plan on replacing it soon. Maybe in the future, we will convert to propane. Looks like the HVAC company is only offering Lennox right now.
Suggest you try 5-6 companies and get quotes from all. Ask for Manual J and you'll quickly find out who is serious about obtaining your work.
User avatar
TomatoTomahto
Posts: 14276
Joined: Mon Apr 11, 2011 1:48 pm

Re: Heat pump in New England

Post by TomatoTomahto »

Big Dog wrote: Tue Jul 19, 2022 10:09 am
indexfunds wrote: Tue Jul 19, 2022 10:05 am Geothermal would be out of the question for us due to price. We have a high efficiency oil boiler and do not plan on replacing it soon. Maybe in the future, we will convert to propane. Looks like the HVAC company is only offering Lennox right now.
Suggest you try 5-6 companies and get quotes from all. Ask for Manual J and you'll quickly find out who is serious about obtaining your work.
Absolutely. Odds are that a company in New England offering only Lennox isn’t whole heartedly in the ASHP game.
I get the FI part but not the RE part of FIRE.
cmr79
Posts: 169
Joined: Mon Dec 02, 2013 4:25 pm

Re: Heat pump in New England

Post by cmr79 »

I don't know...it isn't very unusual for an HVAC company to only offer equipment from one brand, and not everyone can offer Mitsubishi, Fujitsu or Daikins. Mitsubishi ductless units seem to be a lot more common, but when looking at ducted units (what OP needs), all three of those brands are minor players compared to Carrier, Lennox, Rheem, Trane and Goodman. OP should obviously look into other quotes, but it might not be possible for them to find an HVAC company that can install a specific and less common product like a Mitsubishi H2i Hyper ground-mounted ducted ASHP even if it is a bit more efficient in very cold conditions than the more common brands.

We have a similar setup to what OP is considering--Lennox ASHP with a backup propane furnace in a northeastern climate--and are happy with it.

This is an interesting study on ASHP use in cold weather climates based mostly out of Massachusetts:
https://cadmusgroup.com/articles/reside ... northeast/
TheOscarGuy
Posts: 1231
Joined: Sat Oct 06, 2012 1:10 pm
Location: Where I wanna be.

Re: Heat pump in New England

Post by TheOscarGuy »

indexfunds wrote: Mon Jul 18, 2022 9:13 pm Hello,

We are looking to replace our AC unit and are wondering if any of you who live in New England or other cold winter climates have experience with heat pumps. Our coldest month is 34/12 F (high/low). The hottest month is 82/58 F (high/low), although it's been in the 90s recently. We are looking at Lennox and Trane. Lennox has single, two-speed, and variable speed. We have an oil boiler for heat. Oil was $5.69 a gallon. Electricity cost is 19 cents per kWh.

Thanks
put in new in march so too new so far used both heat and cooling applications. My overall electricity consumption has been reduced, and we have replaced just one level so far. Its not the cheapest but had to be done as our AC was ready to give up.
In about a year I can give you a better idea. If oil stays high it would obviously save $$ but not sure about long term, and how much is break even period. we did it because we had to, not because we wanted to save any heating or cooling bills.
CRC301
Posts: 193
Joined: Sat Feb 14, 2015 1:31 pm

Re: Heat pump in New England

Post by CRC301 »

OP, lots of folks have recommended air-source cold-climate heat pumps and I would agree with them. There are lots of folks and companies discussing them for New England over on the Green Building Advisors forum (https://www.greenbuildingadvisor.com/qa). You might check that forum out to get since ideas on what they recommend for your area.

As others have said, the asian manufacturers (specifically the Japanese ones) have a very long history in inverter-driven cold climate heat pump design. Ask around for any local folks that have found good companies they trust. In addition I would cross-reference the recommendations with the manufacturer contractor lookup tools and ensure they are diamond/comfort-pro/elite: The certified installers will have the best warranty and higher likelihood of a good install. They might be more expensive though. Of those, Mitsubishi is probably going to be your best bet as far as service options and parts distribution network.

You can look into dual-fuel as well (i.e. oil/gas furnace with heat-pump coil) but I'm not sure any of the true (i.e. 0F full capacity) cold climate heat pumps support that mode. Since you already have oil furnace/boiler, you could ask them about using a hydronic coil as supplemental heat.

Good luck!
User avatar
willthrill81
Posts: 32250
Joined: Thu Jan 26, 2017 3:17 pm
Location: USA

Re: Heat pump in New England

Post by willthrill81 »

The new, most efficient heat pumps are still very efficient down to temperatures below zero. Older models were only efficient down to around 40F.

Depending on your climate, home, and the specific model, a heat pump may be all you need. But considering the importance of home heating, I've always gravitated toward having some form of backup heating. We have a natural gas furnace as our primary heat source, but we also have a natural gas fireplace that can operate without electricity at all and keep the home reasonably warm. And I also keep several 20# propane tanks and a Mr. Buddy heater that could keep one bedroom warm for a couple of weeks.
ondarvr
Posts: 169
Joined: Tue Dec 22, 2020 6:03 pm

Re: Heat pump in New England

Post by ondarvr »

Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
User avatar
willthrill81
Posts: 32250
Joined: Thu Jan 26, 2017 3:17 pm
Location: USA

Re: Heat pump in New England

Post by willthrill81 »

ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
User avatar
just frank
Posts: 1505
Joined: Sun Nov 02, 2014 4:13 pm
Location: Philly Metro

Re: Heat pump in New England

Post by just frank »

Yup... many ways to go here OP.

Don't know if you have one system or two (like upstair and down).

Option 1: central with existing ducts
You could go for a central Heat Pump system using your existing AC ductwork. This has the advantage of using existing ductwork, but can be undersized for your heat load (bc the tonnage/power of the HP needs to match the duct sizing). So, if you just use the existing ducts, the system would work fine above 35 or 40°F or something, and you could keep the boiler and have it wired to help during cold weather (dual fuel). This would be the cheapest option, as there would be no new ductwork or major wiring required, and it would save about 30-50% of your oil bill.

Option 2: central with upsized/new ducts
If you want to ditch the oil completely, you will probably have to upsize the ductwork.... this might be existing ductwork with a little upsizing and a couple branches added. This obv gets pretty technical bc it has to deliver heat to your existing space... and this both requires expertise and $$$. You are essentially redesigning the existing air distribution system. In my case, I had the installer come back after one season to add a branch to a place that needed more heat, and upsize one duct. Trial and error, but he was cheap and a 'hack'.

One option is to keep the boiler for another season or two as backup, even if you have a system designed to cover your needs. Oil is probably still cheaper than the electrical resistance strips that the HP needs for backup (and defrost). I kept my boiler for 2-3 years, wired as backup, and bc it provided my hot water. I then ditched the boiler, the oil tank, and put in a heat pump water heater HPWH after I knew the HP could heat the house. On the heat pump, all that needed to change was a wire on the thermostat to call the strips instead of the boiler.

The electric strips add expense, bc they need heavy wiring and probably a 200A breaker panel.

Option 3: Lots of minisplits, or multi-headed minisplits.
You can get mini-splits. IMO the touted advantage of 'ductless' minis over central systems with inverter drive compressors and well sealed ducts is minimal. The makers of the old central systems (like goodman) have largely been bought out by the East Asian companies and the technology in those units modernized to be like minis in how they work (at least the inverter models). They also make ducted minis... some that can serve multiple rooms, which blurs the lines between mini and a central system. These systems start to get kind of expensive approaching that of central systems, so I'm not a fan.

I picked Option #2, and assume that is what you will end up with... agree with others that you need multiple bids.

Last thing... if new ducting is placed in unconditioned space (like and attic) make sure it is well sealed by mastic before getting wrapped in insulation. MY hack installer lied to me about that... and I had to have the whole system torn down, sealed and rewrapped.
ondarvr
Posts: 169
Joined: Tue Dec 22, 2020 6:03 pm

Re: Heat pump in New England

Post by ondarvr »

willthrill81 wrote: Tue Jul 19, 2022 7:12 pm
ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
I got bids, they were obscene, did research and installed it myself, it was much easier than I expected. Several places sell DIY friendly kits.
User avatar
willthrill81
Posts: 32250
Joined: Thu Jan 26, 2017 3:17 pm
Location: USA

Re: Heat pump in New England

Post by willthrill81 »

ondarvr wrote: Tue Jul 19, 2022 8:49 pm
willthrill81 wrote: Tue Jul 19, 2022 7:12 pm
ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
I got bids, they were obscene, did research and installed it myself, it was much easier than I expected. Several places sell DIY friendly kits.
That's good to know, but there are many here who don't even change the oil in their vehicles themselves, so a DIY heat pump is only applicable to some.
ondarvr
Posts: 169
Joined: Tue Dec 22, 2020 6:03 pm

Re: Heat pump in New England

Post by ondarvr »

willthrill81 wrote: Tue Jul 19, 2022 9:42 pm
ondarvr wrote: Tue Jul 19, 2022 8:49 pm
willthrill81 wrote: Tue Jul 19, 2022 7:12 pm
ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
I got bids, they were obscene, did research and installed it myself, it was much easier than I expected. Several places sell DIY friendly kits.
That's good to know, but there are many here who don't even change the oil in their vehicles themselves, so a DIY heat pump is only applicable to some.
It can be expensive to not know how to learn new things. If you have the money, pay somebody to do it, if not, get out the Google machine.
CRC301
Posts: 193
Joined: Sat Feb 14, 2015 1:31 pm

Re: Heat pump in New England

Post by CRC301 »

willthrill81 wrote: Tue Jul 19, 2022 9:42 pm
ondarvr wrote: Tue Jul 19, 2022 8:49 pm
willthrill81 wrote: Tue Jul 19, 2022 7:12 pm
ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
I got bids, they were obscene, did research and installed it myself, it was much easier than I expected. Several places sell DIY friendly kits.
That's good to know, but there are many here who don't even change the oil in their vehicles themselves, so a DIY heat pump is only applicable to some.
Another thing to think about with DIY is that it could be difficult to find someone to service it? There is DIY-friendly installs but troubleshooting (eventual) problems may require the expertise and/or special equipment that only HVAC tech's have access to (and they may not even agree to troubleshoot a DIY unit). That could be mitigated by the sheer cost savings of the DIY system; you might be able to buy 2-3 of the DIY systems for the price a certified installer may charge and warranty a single "mainstream" version.
ondarvr
Posts: 169
Joined: Tue Dec 22, 2020 6:03 pm

Re: Heat pump in New England

Post by ondarvr »

I bought all the equipment, and learned to use it.

The bids were from $16,000 to $20,000.

My retail cost for the high end Mistubishi equipment in the bid was about $5,500 all in. That was for one 3 zone system.

I bought one 3 zone and two single zone systems, along with all the equipment to install it myself for about $4,500. This was high end equipment from a major supplier, but through their US DIY friendly division.

To replace a component was less than a service call from the contractor, plus they have a complete parts catalog and troubleshooting section.

So I basically paid myself $15,000 to install it. Plus I got significantly more equipment, one system went in the shop and two went in the house. There are two house systems so there's always a backup, and in mild weather you only need to run one so it's not oversized.
Valuethinker
Posts: 45273
Joined: Fri May 11, 2007 11:07 am

Re: Heat pump in New England

Post by Valuethinker »

willthrill81 wrote: Tue Jul 19, 2022 9:42 pm
ondarvr wrote: Tue Jul 19, 2022 8:49 pm
willthrill81 wrote: Tue Jul 19, 2022 7:12 pm
ondarvr wrote: Tue Jul 19, 2022 6:34 pm Every time this subject comes up you get the people unfamiliar with newer technology on heat pumps claiming the same old "it only provides heat down to 40F" stuff.

There is whole different world of heat pumps that are very common in the rest of the world that work great in below zero temps.

The fact that many contractors just sell and install the same old old school stuff is a crime, buts it's all they know. Also, contractors that are selling and installing this very efficient equipment frequently overcharge significantly for the install. Only because they can.

If natural gas is available the super efficient heat pump may not be the best deal, NG can be very cheap to heat with. But NG is being phased out in many areas, so cost and availability may be worse in the near future.
While I agree that the newer heat pumps are awesome, that's irrelevant unless you can hire someone in your area qualified to install them. That could be an issue in some places.
I got bids, they were obscene, did research and installed it myself, it was much easier than I expected. Several places sell DIY friendly kits.
That's good to know, but there are many here who don't even change the oil in their vehicles themselves, so a DIY heat pump is only applicable to some.
In England, anything to do with heating has to be installed by licensed boiler engineers (used to be called CORGI but it's changed) and electricians.
Signed off by buildings inspector (that's probably not true with a simple replacement).

If one did not have the certificate for that then it might become an issue in the resale of the property. It would also invalidate your insurance. And of course you could kill someone, an incidental side issue.

There are plenty of bodged installs by unlicensed people out there, and this happens from time to time.
Valuethinker
Posts: 45273
Joined: Fri May 11, 2007 11:07 am

Re: Heat pump in New England

Post by Valuethinker »

just frank wrote: Tue Jul 19, 2022 7:21 pm Yup... many ways to go here OP.

Don't know if you have one system or two (like upstair and down).

Option 1: central with existing ducts
You could go for a central Heat Pump system using your existing AC ductwork. This has the advantage of using existing ductwork, but can be undersized for your heat load (bc the tonnage/power of the HP needs to match the duct sizing). So, if you just use the existing ducts, the system would work fine above 35 or 40°F or something, and you could keep the boiler and have it wired to help during cold weather (dual fuel). This would be the cheapest option, as there would be no new ductwork or major wiring required, and it would save about 30-50% of your oil bill.

Option 2: central with upsized/new ducts
If you want to ditch the oil completely, you will probably have to upsize the ductwork.... this might be existing ductwork with a little upsizing and a couple branches added. This obv gets pretty technical bc it has to deliver heat to your existing space... and this both requires expertise and $$$. You are essentially redesigning the existing air distribution system. In my case, I had the installer come back after one season to add a branch to a place that needed more heat, and upsize one duct. Trial and error, but he was cheap and a 'hack'.

One option is to keep the boiler for another season or two as backup, even if you have a system designed to cover your needs. Oil is probably still cheaper than the electrical resistance strips that the HP needs for backup (and defrost). I kept my boiler for 2-3 years, wired as backup, and bc it provided my hot water. I then ditched the boiler, the oil tank, and put in a heat pump water heater HPWH after I knew the HP could heat the house. On the heat pump, all that needed to change was a wire on the thermostat to call the strips instead of the boiler.

The electric strips add expense, bc they need heavy wiring and probably a 200A breaker panel.

Option 3: Lots of minisplits, or multi-headed minisplits.
You can get mini-splits. IMO the touted advantage of 'ductless' minis over central systems with inverter drive compressors and well sealed ducts is minimal. The makers of the old central systems (like goodman) have largely been bought out by the East Asian companies and the technology in those units modernized to be like minis in how they work (at least the inverter models). They also make ducted minis... some that can serve multiple rooms, which blurs the lines between mini and a central system. These systems start to get kind of expensive approaching that of central systems, so I'm not a fan.

I picked Option #2, and assume that is what you will end up with... agree with others that you need multiple bids.

Last thing... if new ducting is placed in unconditioned space (like and attic) make sure it is well sealed by mastic before getting wrapped in insulation. MY hack installer lied to me about that... and I had to have the whole system torn down, sealed and rewrapped.
Nice summary & nice to see you posting again.

I hadn't considered properly that the OP has rads. This does indeed push towards OP retaining oil-fired boiler.

Poster talzara told us that in the USA, there are no air-to-water heat pumps. I did find one supplier in Canada (Montreal). They are of course ubiquitous for the rest of us-- and from the same manufacturers (Japanese and German, primarily).

In the situation of a relative's home in a NE North American city (so hot summers, cold winters), she has rads, and she has a miniduct system for AC installed about 60 years later (house was built in 1920s). This combination works well although for reasons too difficult to explain here, she has a direct (induction) heating system for her rads, rather than a heat pump.
User avatar
just frank
Posts: 1505
Joined: Sun Nov 02, 2014 4:13 pm
Location: Philly Metro

Re: Heat pump in New England

Post by just frank »

Valuethinker wrote: Wed Jul 20, 2022 3:33 am Nice summary & nice to see you posting again.

I hadn't considered properly that the OP has rads. This does indeed push towards OP retaining oil-fired boiler.

Poster talzara told us that in the USA, there are no air-to-water heat pumps. I did find one supplier in Canada (Montreal). They are of course ubiquitous for the rest of us-- and from the same manufacturers (Japanese and German, primarily).

In the situation of a relative's home in a NE North American city (so hot summers, cold winters), she has rads, and she has a miniduct system for AC installed about 60 years later (house was built in 1920s). This combination works well although for reasons too difficult to explain here, she has a direct (induction) heating system for her rads, rather than a heat pump.
Nice to be back!

The issue with air to water HPs is that the radiation in the US is often designed to work with water at 170-180°F, and will not provide enough BTUs at a lower water temp (delivery in a passive convection system being non-linear in Delta_T). Compared to western EU and UK, the outdoor air temps are also decided colder in the Northeast and Upper Midwest. Thus the temperature 'lift' is much higher here and very hard on the system COP.

There is also the fact that nearly everywhere in the US needs AC at this point, and that requires ducting to manage latent (humidity) loads. So everyone needs to have ducts anyway. In older construction in colder US climates, one often has old (high temp) hydronic radiation AND retrofit ducting sized to AC loads.

A lot of folks vilify ducts as a source of loss. This is well deserved for ducts as they were installed pre-2000 or so. But properly sealed and code-insulated ducts lose 2-3% of BTUs in delivery, or less. The only people left vilifying ducts here now are folks trying to sell ductless minis and hydronic HPs.

The situation is similar with tank water heaters. For years, under-insulated tanks were a major source of energy waste, but Energy Star codes requiring more insulation make tank losses quite modest (again less than 5%). On the one side, we will have tank vilifiers in the US who are trying to sell demand HW heater systems (usually of EU manufacture, where tanks are still often anathema). On the other side, we now have tanks with air to water HPs, (drawing the air from indoors), HPWHs, which have a COP of >3. And thus are cheap to operate compared to any tankless system, despite losing 5% in tank losses. Diverging tech. The same natgas burned in a plant and running a HPWH will make 2X the hot water that a tankless natgas system will. And with lower maintenance than a finicky demand system.
talzara
Posts: 2771
Joined: Thu Feb 12, 2009 7:40 pm

Re: Heat pump in New England

Post by talzara »

Valuethinker wrote: Wed Jul 20, 2022 3:33 am Poster talzara told us that in the USA, there are no air-to-water heat pumps. I did find one supplier in Canada (Montreal). They are of course ubiquitous for the rest of us-- and from the same manufacturers (Japanese and German, primarily).
I didn't say that "there are no air-to-water heat pumps" in the United States. I said that the Asian HVAC manufacturers do not sell their air-to-water heat pumps in the United States.

There are some American companies that make air-to-water heat pumps, but they come out of the chiller line, which is on the commercial side. It's very hard to find a residential HVAC contractor who has experience with the equipment. You can use a commercial contractor, but they won't have experience with residential work.

It's not like buying an Asian air-to-water heat pump in Germany, where there are a lot of residential contractors. Germany installed 100,000 air-to-water heat pumps in 2020, including in 53% of new houses: https://heatpumpingtechnologies.org/wp- ... 210907.pdf
just frank wrote: Wed Jul 20, 2022 7:39 am The issue with air to water HPs is that the radiation in the US is often designed to work with water at 170-180°F, and will not provide enough BTUs at a lower water temp (delivery in a passive convection system being non-linear in Delta_T). Compared to western EU and UK, the outdoor air temps are also decided colder in the Northeast and Upper Midwest. Thus the temperature 'lift' is much higher here and very hard on the system COP.
Radiant floor heating is also much more common in Europe, especially in new construction.

You can keep the water at a much lower temperature when you have the entire floor as a radiating surface. You feel warmer when your feet are in contact with a warm floor, so you can also set the thermostat lower.
Post Reply