[Small, Portable, and Ductless Air Conditioners]

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Spirit Rider
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by Spirit Rider » Wed Jul 11, 2018 9:05 am

I don't think I have ever heard of a ground source retrofit where there wasn't already existing ductwork.

The only one I am familiar with was as suggested by Alf 101: This was essentially drilling a well with a sufficient flow rate.

They had major hassles getting federal and state regulatory approval for the water discharge even though they had a water drainage easement 50ft. from their house.

pshonore
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by pshonore » Wed Jul 11, 2018 9:58 am

Spirit Rider wrote:
Wed Jul 11, 2018 9:05 am
I don't think I have ever heard of a ground source retrofit where there wasn't already existing ductwork.

The only one I am familiar with was as suggested by Alf 101: This was essentially drilling a well with a sufficient flow rate.

They had major hassles getting federal and state regulatory approval for the water discharge even though they had a water drainage easement 50ft. from their house.
Sounds like an "open loop" pump and dump system. There are also closed loop systems.

http://www.geothermalgenius.org/how-it- ... op-fields/

VaR
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by VaR » Wed Jul 11, 2018 11:33 am

Alf 101 wrote:
Wed Jul 11, 2018 8:46 am
Also, with an oil furnace and baseboard heat, I fear this might also require great rework inside the house to make it functional.
Wait, you have an oil furnace? In your original post you said you only had baseboard heat. Electric resistance baseboard heat would be wildly expensive to run in your climate zone, this is what made me wonder if switching it out would be cost effective.

So do you have electric resistance baseboard heat or do you have a oil-filled or hydronic baseboard heating with an oil furnace? This might mean that I have a fundamental misunderstanding of your situation.

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Alf 101
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by Alf 101 » Wed Jul 11, 2018 1:00 pm

My error. It is an oil furnace with hydronic baseboard heat. This is a new one to me -- up to now everywhere I lived had natural gas.

I'll have to go back and check what our average fuel costs are per month over the winter. I did talk last night to a HVAC contractor, who I was able to connect up with through a personal connection. He said that he installed a Fujitsu mini-split system for his 2400 sq. ft house. He said the average cost to cool the house during the summer was about $30/month. As for heating, he said he could run it into the shoulder season -- depending on the year maybe into the first days of December, and firing back up in early March. He quoted the price of heating during this late fall/early spring period amounted to about $60/month extra on average in the electric bill. Of course he was trying to sell me something, but if true, the ROI may take some time. Still our realtor was very convinced this was a feature that added to the value of a home when selling it.

More to come...

VaR
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by VaR » Wed Jul 11, 2018 3:18 pm

Alf 101 wrote:
Wed Jul 11, 2018 1:00 pm
My error. It is an oil furnace with hydronic baseboard heat. This is a new one to me -- up to now everywhere I lived had natural gas.

I'll have to go back and check what our average fuel costs are per month over the winter. I did talk last night to a HVAC contractor, who I was able to connect up with through a personal connection. He said that he installed a Fujitsu mini-split system for his 2400 sq. ft house. He said the average cost to cool the house during the summer was about $30/month. As for heating, he said he could run it into the shoulder season -- depending on the year maybe into the first days of December, and firing back up in early March. He quoted the price of heating during this late fall/early spring period amounted to about $60/month extra on average in the electric bill. Of course he was trying to sell me something, but if true, the ROI may take some time. Still our realtor was very convinced this was a feature that added to the value of a home when selling it.

More to come...
A ballpark estimate for the shoulder season savings of a heat pump over heating oil is 40% - but only for the months that the heat pump can operate, so say down to 0 F for Mitsubishi but I'd see if you can get some better estimates of heat pump efficiency under the 17 F that I was able to find.

A geothermal heat pump will net you 65% savings the entire winter and some summer savings as well. But as you said, the upfront cost will be high since you don't have an existing forced air setup. Too bad they don't have ductless geothermal. (Actually, I think they might but it seems very specialized)

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TheGreyingDuke
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by TheGreyingDuke » Tue Sep 25, 2018 7:32 am

1) If you go ahead with the minisplit option make sure that you get one of the "cold climate" units. Those that we see in southern Asia are cheap and do not perform under about 30 degrees F to heat.

2) If you have oil heat you should have someone fo an analysis to see if you will save money by relying on the minisplit for your heat for much of the year. Here in Upstate NY electricity is relatively affordable ($.12 kWh) and oil is not. For those of us with natural gas, the equation is quite different.

I am working as a volunteer on a project sponsored by the Cornell Cooperative Extension that helps people make good decisions about these matters.

http://www.solartompkins.org/news/signs ... e-benefits
"Every time I see an adult on a bicycle, I no longer despair for the future of the human race." H.G. Wells

PinotGris
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by PinotGris » Sat Oct 06, 2018 7:37 pm

Wonder if the OP decided to go with the mini-split installation or not.
We are getting estimates for a mitsubishi. It looks like it will two condensers and 4 units.
I wonder how it looks outside on the siding with all the conduits running. I have been googling a few images but there are not many outside, only interiors.
And if you need to paint or wash or install new siding what happens?

VaR
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by VaR » Sun Oct 07, 2018 12:18 am

PinotGris wrote:
Sat Oct 06, 2018 7:37 pm
Wonder if the OP decided to go with the mini-split installation or not.
We are getting estimates for a mitsubishi. It looks like it will two condensers and 4 units.
I wonder how it looks outside on the siding with all the conduits running. I have been googling a few images but there are not many outside, only interiors.
And if you need to paint or wash or install new siding what happens?
Use Google image search with the following search terms (without quotes), "mitsubishi line-set cover".

Basically, it they look like plastic rain gutter downspouts.

mouses
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by mouses » Sun Oct 07, 2018 6:42 am

28fe6 wrote:
Mon Jul 02, 2018 5:08 pm
I'm having this exact problem about my garage, which in NC summer is uninhabitable. I only need to reduce the temperature and humidity to non-sauna levels. I don't need it fully climate controlled, and weighing my options.

Mini split: best end result, most efficient, only require 3" hole through the house to install. Downside: nobody locally will install one. It drives me crazy because these things are a dime a dozen in Japan, but it's not part of the HVAC culture thing here. So I don't know if the codes or HOA would approve for the same reason...they aren't familiar. They have DIY options mini split options for about $1000 that I could stealth-install and get away with until I sell the house at least.

Window unit: not permanent; would do the trick for cooling. Downside: need to install a window first which adds $$. Probably not HOA approved, but it's not permanent at least, and a window isn't going to hurt house value. I figure $200 for the window and $400 for the unit. So not that much cheaper...

Portable: I just don't have confidence they work very well. I could vent through my garage wall or install a window to vent it through and HOA would be none the wiser.

I'm leaning towards installing a window first, then putting in a window unit and if the HOA ding me, I'll fall back to a portable vented through the same window. If I were more confident in staying in this house for a long time I would install a split system.
Reading other posts, it seems that you don't need a window for a window unit, they can be placed through the wall, although I don't know how the cost compares.

I also have an oven-like garage, and have been wondering about things like a ceiling fan with both doors open.

Spirit Rider
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by Spirit Rider » Sun Oct 07, 2018 8:20 am

mouses wrote:
Sun Oct 07, 2018 6:42 am
Reading other posts, it seems that you don't need a window for a window unit, they can be placed through the wall, although I don't know how the cost compares.
This is not correct.

Window units are designed such that a significant portion extends outside for heat dissipation.

Thru-the-wall units may look similar, but are specifically designed to operate efficiently when installed directly thru a wall.

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Ged
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by Ged » Sun Oct 07, 2018 8:50 am

28fe6 wrote:
Mon Jul 02, 2018 5:08 pm
Mini split: best end result, most efficient, only require 3" hole through the house to install. Downside: nobody locally will install one.
I wouldn't give up on the minisplit for your garage. I put a Mitsubishi in mine along with attic insulation here in southern NJ and it has been a glorious improvement. Have you tried calling Mitsubishi or checking their list for installers? There are many small businesses around here that use them.

Here's Mitsubishi's contractor finder:

https://www.mitsubishicomfort.com/get-s ... ontractors

If I had a house that didn't have air ducts I wouldn't hesitate now that I've lived with one for a few years.

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Alf 101
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by Alf 101 » Tue Feb 05, 2019 9:47 am

As the OP, I thought I should circle back with an update -- now that we've had a mini-split system installed. To recap, we had recently moved, with my wife working out of a home office in the new house. While generally well insulated, last summer was a hot one, and it was pretty uncomfortable without AC. Perhaps more concerning, we could also tell long periods of high humidity were doing a number -- doors and cabinets no longer shutting properly, cardboard boxes thinning, pets uncomfortable, etc. This house has hot water baseboards, no ducts, so this seemed the simplest way to provide central air conditioning.

While our neighbors described the summer has uncharacteristically warm and humid, we had seen enough. I began contacting HVAC professionals last summer and into the fall, saying that we had just found out about mini-splits, were curious in learning more, and could you come out and give us a quote? Here are a few of my impressions:

1. Summer is probably not the time to get a quote and a mini-split system installed. Especially in a very hot summer, HVAC professionals may not have much of any space on their calendars. We started the quote request process in late summer, agreed on a contract in early-mid November, and just had the system installed. Of course if you were insistent this is something you must have immediately, that could be possible, but I believe you would pay a premium.

2. Not every HVAC has a lot of experience with these systems. We took two well-known and regarded brands, Fujitsu and Mitsubishi, and did a search for their registered elite contractors within a reasonable range. Not only does that give some confidence they have familiarity with these systems, there's some proof. Using said contractor also gives you an extended warranty on parts and the compressor. One point is that these elite contractors also seem to do a lot of work for commercial properties and businesses, which why it took so long for the system to get installed.

3. With any project, get multiple quotes. As a rule, I shoot for three; on this one I think we went with seven. On one hand, as you might expect, the quotes varied in price. What was particularly interesting, however, was that each HVAC professional presented a different approach. And while I don't claim to be any kind of expert, I did know two things -- we wanted to cool the rooms we used most, and hot air rises/cold air drops. Some proposals -- unit 35,000 BTU unit for the whole house, in the hallway at the top of the stair; wall units at floor level; or a floor unit that would blow cool air from a 2nd bedroom across the hall into the master bedroom, and not flow down the stairs in between -- all didn't pass the sniff test.

In the end we had a 12,000 BTU wall unit installed in our master bedroom, to cool the upstairs (about 800 sq. ft.), and a 18,000 BTU wall unit installed in the main room downstairs (1000-1100 sq. ft.), which can be angled to blow into the kitchen and back hallway. The compressor is sized such that we could add a third unit later, either in the back of the house on the first floor, or the second bedroom upstairs. We ended up paying $7500-7600; adding a third unit would have bumped the price up $2000-2500 more. Because we have trees and good shade, and the back of the house doesn't get direct sun in the hottest part of the day. So we liked having the option, but aren't sure whether we need a 3rd unit yet. We will see.

One option, that we explored only briefly, was that of also providing heating through the mini-split system. Our system is efficient for shoulder season heating, but not much below 40 F. There are systems that promise heating down to lower temperatures, though this comes at higher costs than we wanted to spend for this project. We live fairly far north; in a more temperate climate, this could be something to explore. I did a quick back-of-the-napkin comparing the installation and operating costs of a low temperature mini-split heating system vs. a pellet stove, and it didn't seem to favor the hyper-heating option.

Finally, two things. First is that every house is different. If you lived in a barn, with a completely wide open layout, how you heat and cool the air is fairly straightforward. To the degree your home varies from this floor plan, its flow and how rooms are divided, will change the project cost. Our situation was not all that cut and dry.

Secondly, I asked about long term costs. There's an extended warranty, and the coolant is in a closed loop, so this needs no regular maintenance. I was advised, however, that we should call them every 1-2 years to clean out the condenser. Basically, the argument goes, pollen will clog up the filters and reduce the system's efficiency. Given that we live surrounded by woods, and have a pretty sizable garden, this is plausible. I'm curious, however, if others have been told the same.

One problem with having an air conditioning system installed in winter, is that you don't use it a lot coming out of the gates. We tested it, and it does work -- they system runs and it blows air -- but we won't know for another 4 or so months. Of course, last summer may have been the outlier, that once-in-a-lifetime extended heat wave. That would be OK, but we didn't want to bet on that.

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TimeRunner
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by TimeRunner » Tue Feb 05, 2019 3:09 pm

I had bookmarked this post - thanks for taking the time to circle back. It's disconcerting that "elite" installers would propose solutions that clearly wouldn't work well. Give us an update once Summer fully kicks in. Thanks again. :beer
"It is not the strongest of the species that survives nor the most intelligent that survives. It is the one that is most adaptable to change." - Charles Darwin

dowse
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Re: [Small, Portable, and Ductless Air Conditioners]

Post by dowse » Sun Mar 17, 2019 4:32 pm

Also following this thread with interest. Thanks to the op for the latest update. We are determined not to live through another brutal summer without better a/c. We are now in the process of getting quotes for a 4-zone, single condenser ductless system, probably 36K BTU total (6+9+9+12). So far only one quote for $12.300. At first I thought that seemed high, but after reading this thread, sounds about right. Our house has no ducts, and a semi-finisched attic, so central air is not really a viable option. Locations of the indoor units will be quite straightforward. An existing 240V/50A electrical line originally put in for a hot tub that is being permanently removed will be repurposed for the a/c unit. We're currently waiting for another quote to come back, and we have one more appointment set up.

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