Detached garage: Recommended ways to heat water for shower? Save space and money?

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doss
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Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by doss » Fri Jan 17, 2020 1:07 pm

I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng). The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

Recommended options.....go tankless? Get a small water heater (40g?) and stash it somewhere under the stairs? Beef up my main house water heater (we are going to be replacing this soon) and run a pipe from house to garage?

Goals: Save space, save money....

bob60014
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by bob60014 » Fri Jan 17, 2020 1:11 pm

For limited use (?), Tankless.

Of course the question is, the room and shower, is it legal?
Last edited by bob60014 on Fri Jan 17, 2020 1:38 pm, edited 1 time in total.

Jack FFR1846
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Jack FFR1846 » Fri Jan 17, 2020 1:19 pm

Why detached? As the owner of a garage 200 feet from the house, I know all about the advantages (can make all kinds of noise at 1 in the morning and weld stuff and the wife doesn't hear and doesn't complain) and disadvantages (It's really cold in the middle of January at 1 in the morning, even with the welder heating things up).

We've considered building another garage attached to the house because nobody wants to walk 200 feet through the snow to get to a car. Mine is unheated. Attached, you could open a door and let the main house heat flow in....at least a little.

I have no water. Just electric. You'd need to figure out a way to keep the water inlet from freezing. For washing hands, I have waterless soap and paper towels. And I wear gloves so my hands don't get so dirty and cut up in the first place.
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by fru-gal » Fri Jan 17, 2020 1:25 pm

I surely wish my garage were attached to my house. It would be so much more convenient and comfortable, esp. getting groceries into the house in winter.

What are you doing that you need it to be detached and have a shower? If you're working with tools, keep some paper towels out there and use them to open the door to the house where you have a bathroom.

Or are you planning on renting this out?

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Luke Duke » Fri Jan 17, 2020 1:56 pm

I think that a tankless electric water heater is a no-brainer in this situation.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by dm200 » Fri Jan 17, 2020 2:19 pm

Luke Duke wrote:
Fri Jan 17, 2020 1:56 pm
I think that a tankless electric water heater is a no-brainer in this situation.
Why?

Seems to me a small one, with a tank would satisfy the requirements.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by smitcat » Fri Jan 17, 2020 2:54 pm

doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng). The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

Recommended options.....go tankless? Get a small water heater (40g?) and stash it somewhere under the stairs? Beef up my main house water heater (we are going to be replacing this soon) and run a pipe from house to garage?

Goals: Save space, save money....
We did this a while back - similar sized garage and distance from the home. In our area the easiest and most economical method was an electric hot water heater with a tank. I do not remember the tank size but it was fairly small. If we were going to use oil or gas heat in the garage that would have made a more complicated decision but with an all electric configuration it was a no brainer in our case.
Good luck with the new build.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by scophreak » Fri Jan 17, 2020 3:14 pm

How often do you envision needing to use the shower/hot water? My parents have a detached garage and though they don't have a shower all hot water is supplied by a tankless electric water heater. For infrequent use this makes the most sense...you're not keeping a reservoir of hot water at all times. If you'll be using this daily then the math may change.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by scophreak » Fri Jan 17, 2020 3:15 pm

doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng). The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

Recommended options.....go tankless? Get a small water heater (40g?) and stash it somewhere under the stairs? Beef up my main house water heater (we are going to be replacing this soon) and run a pipe from house to garage?

Goals: Save space, save money....
Also...I wouldn't necessarily consider 40g to be a "small" water heater. We have only a 50g to service our entire home with 2 adults and 2 children.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by suemarkp » Fri Jan 17, 2020 3:30 pm

What utilities can be available at the garage? Natural gas? How much electricity? Obviously water.

Electric tankless water heaters require a huge amount of electricity, probably at least 80 amps just for it. If you add a mini split, and a car charger, you could require a 200 amp feeder to the garage and that could be pricy.

Look at the complete costs to install. Gas line. Chimney. Gas appliance cost versus electric. Gas operating costs may be less, but in a garage you may never use enough to make up for the install costs. If electric feeder requires house service to be increased, that could be a big price bump.
Mark | Kent, WA

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by shunkman » Fri Jan 17, 2020 3:39 pm

At our getaway cabin we have two 6 gallon electric water heaters stacked one on top of the other. The well water is very cold and this setup heats the water quickly and produces enough water for a couple of showers. It almost works like an on demand system but you need about an hour for the initial heat-up. And the supply is not continuous but it is more than enough for showering, doing dishes, etc.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by chevca » Fri Jan 17, 2020 4:05 pm

Tankless isn't going to satisfy the save money part. They're pretty spendy. A small set up like shunkman described is probably your best bet.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Shallowpockets » Fri Jan 17, 2020 6:00 pm

This new garage will be 50’ away from your house which has a shower. Why do you need another shower right in garage?
Water heater is one thing. Water supply and drain is another. All this so as not to have to walk 50 ‘ to a shower?
Sounds OK, but at what cost verses use.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by toast0 » Fri Jan 17, 2020 6:55 pm

suemarkp wrote:
Fri Jan 17, 2020 3:30 pm
Electric tankless water heaters require a huge amount of electricity, probably at least 80 amps just for it.
I was going to say the same thing; we wanted to replace a small failed tankful heater in our last detached garage with a shower, but upgrading the electric service to make it possible wasn't realistic. Gas fired tankless water heaters may also need a pretty large supply line. Either way, something to figure out the details on before you begin construction, to make sure it's feasible given the existing site.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by BuddyJet » Fri Jan 17, 2020 7:04 pm

Since space is an issue, I would look at about a 20 gallon heater on a shelf above the sink.

Here is a link for electric.

https://www.homedepot.com/p/Rheem-Perfo ... /204318374
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Lalamimi » Fri Jan 17, 2020 8:55 pm

put in a sky light and use a camping style water bag. let the sun heat the water.

iamblessed
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by iamblessed » Fri Jan 17, 2020 9:00 pm

Why not something like this https://www.menards.com/main/plumbing/w ... c-8690.htm

About 3.5 feet tall

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Jack FFR1846 » Fri Jan 17, 2020 9:14 pm

Lalamimi wrote:
Fri Jan 17, 2020 8:55 pm
put in a sky light and use a camping style water bag. let the sun heat the water.
I just came in from my detached garage. It's 21 degrees out there. I don't think the sun's going to help.
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Cubicle
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Cubicle » Sat Jan 18, 2020 1:38 am

My biggest concern would be water supply freezing & the drain line back to house. But anyways:

If infrequent use, since you building the garage (from nothing I presume), I'd go tankless if you can get a large enough gas line to the heater.

If frequent use or small gas line, then the smallest tank heater.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Soon2BXProgrammer » Sat Jan 18, 2020 8:39 am

toast0 wrote:
Fri Jan 17, 2020 6:55 pm
suemarkp wrote:
Fri Jan 17, 2020 3:30 pm
Electric tankless water heaters require a huge amount of electricity, probably at least 80 amps just for it.
I was going to say the same thing; we wanted to replace a small failed tankful heater in our last detached garage with a shower, but upgrading the electric service to make it possible wasn't realistic. Gas fired tankless water heaters may also need a pretty large supply line. Either way, something to figure out the details on before you begin construction, to make sure it's feasible given the existing site.
I know someone who uses 2 100lb propane bottles with a tankless propane water heater, so that they didn't have to bring gas to their outbuilding.

They don't use the water a lot, so the propane bottles last quite a while.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Soon2BXProgrammer » Sat Jan 18, 2020 8:40 am

Cubicle wrote:
Sat Jan 18, 2020 1:38 am
My biggest concern would be water supply freezing & the drain line back to house.
ohhh.... people just don't but a big barrel underground (with holes in it) and run grey water into it anymore?

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by michaeljc70 » Sat Jan 18, 2020 8:54 am

I'd go with a small tank heater. A tankless is going to be expensive especially if you live in a place where it gets cold in the winter (you need a more expensive/powerful unit the more you have to raise the temp). They say the average shower uses 17 gallons of water so a 20 gallon tank makes sense to me.

Where I live everyone uses gas water heaters because they are cheaper to run than electric. I'd look at the cost of running the water heater on electric vs. the cost of running a gas line (assuming you don't have a gas line there already).

As others said, a shower in the garage wouldn't be practical for most people, but if you work on cars everyday or work a very messy job and want to shower before going in the house I get it.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Luke Duke » Sat Jan 18, 2020 10:49 am

dm200 wrote:
Fri Jan 17, 2020 2:19 pm
Luke Duke wrote:
Fri Jan 17, 2020 1:56 pm
I think that a tankless electric water heater is a no-brainer in this situation.
Why?

Seems to me a small one, with a tank would satisfy the requirements.
I was basing my statement on a couple of assumptions:
1. The electrical service is sufficient.
2. A garage shower wouldn't get used often.
3. There would be no other hot water demands while the shower is running.

A low-flow shower head only uses 1.5gpm. Even with 37*F inlet water, the following unit can provide enough hot water.
https://www.homedepot.com/p/18-kW-Self- ... /203316216
https://images.homedepot-static.com/cat ... 6e26be.pdf

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Watty » Sat Jan 18, 2020 11:31 am

I was at someones house recently that had build a garage like that with a shower. The shower was being used as a closet to store stuff. :oops:

If you have space an alternative you could look at would be to add an additional bathroom to the side of the house that has doors that open to the outside and then into the house. When you are done working in the garage you can just go straight into the bathroom and shower off then go into the house. You could also combine this with a mudroom.

That would likely cost about the same, or even less, as building a bathroom in the garage and might also add some value when you eventually sell the house.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by iamblessed » Sat Jan 18, 2020 12:22 pm

michaeljc70 wrote:
Sat Jan 18, 2020 8:54 am
I'd go with a small tank heater. A tankless is going to be expensive especially if you live in a place where it gets cold in the winter (you need a more expensive/powerful unit the more you have to raise the temp). They say the average shower uses 17 gallons of water so a 20 gallon tank makes sense to me.

Where I live everyone uses gas water heaters because they are cheaper to run than electric. I'd look at the cost of running the water heater on electric vs. the cost of running a gas line (assuming you don't have a gas line there already).

As others said, a shower in the garage wouldn't be practical for most people, but if you work on cars everyday or work a very messy job and want to shower before going in the house I get it.
Gas is cheaper but if you buy a small electric tank they are only about $100 more a year to run. An electric 30 gallons and under.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by MJS » Sat Jan 18, 2020 1:27 pm

I'm clueless about whether this is legal or cost-effective, but would a $12-15,000 used RV, fifth wheel, or camper van parked next to a very basic garage work? Building code issues, vehicle & building licensing, maintenance, parking codes, cost of running utility lines ... maybe just strip the bathroom out of an RV.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by dm200 » Sun Jan 19, 2020 2:23 pm

Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by bob60014 » Sun Jan 19, 2020 3:12 pm

It would be nice to hear back from the OP with more details.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by smitcat » Sun Jan 19, 2020 3:17 pm

dm200 wrote:
Sun Jan 19, 2020 2:23 pm
Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas
"Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:"
Of course gas needs a few other items when installing:
- source for gas
- flue and/or chimney above the roof peak
- non flammable barrier above heater and on the walls
All of these can easily add to the complexity and costs of utilizing natural gas.
FWIW - we currently have 9 water heaters between our home(s) and where we work. 2 are oil heated , 1 is gas and 6 are electric. I have replaced each one of them over the years and only required 'help' with the gas heater.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by michaeljc70 » Sun Jan 19, 2020 4:22 pm

smitcat wrote:
Sun Jan 19, 2020 3:17 pm
dm200 wrote:
Sun Jan 19, 2020 2:23 pm
Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas
"Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:"
Of course gas needs a few other items when installing:
- source for gas
- flue and/or chimney above the roof peak
- non flammable barrier above heater and on the walls
All of these can easily add to the complexity and costs of utilizing natural gas.
FWIW - we currently have 9 water heaters between our home(s) and where we work. 2 are oil heated , 1 is gas and 6 are electric. I have replaced each one of them over the years and only required 'help' with the gas heater.
We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by jbuzolich » Sun Jan 19, 2020 4:42 pm

Lalamimi wrote:
Fri Jan 17, 2020 8:55 pm
put in a sky light and use a camping style water bag. let the sun heat the water.
Was thinking something similar. Maybe skip the heat and take cold showers. Economical and environmentally friendly, being short.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by friar1610 » Sun Jan 19, 2020 5:07 pm

doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng).The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

This comment doesn't pertain to your basic question but to the size of the garage.

I once had a detached garage with an attic built. When I roughed out what I wanted, it came to something like 25' X 26'. When I started getting bids one contractor recommended that I reduce it to 24' X 24'. He said that way he could use standard lumber sizes, reduce waste and save a lot of money. I took his recommendation and never missed the extra couple of feet. Don't know exactly how much I saved. You may absolutely need the extra feet but just thought I'd pass it on.
Friar1610

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by Jack FFR1846 » Sun Jan 19, 2020 5:09 pm

friar1610 wrote:
Sun Jan 19, 2020 5:07 pm
doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng).The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

This comment doesn't pertain to your basic question but to the size of the garage.

I once had a detached garage with an attic built. When I roughed out what I wanted, it came to something like 25' X 26'. When I started getting bids one contractor recommended that I reduce it to 24' X 24'. He said that way he could use standard lumber sizes, reduce waste and save a lot of money. I took his recommendation and never missed the extra couple of feet. Don't know exactly how much I saved. You may absolutely need the extra feet but just thought I'd pass it on.
That's a great catch!

Our detached garage is 24x36 for that very reason.
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by CheCha54 » Sun Jan 19, 2020 7:55 pm

Go to https://www.garagejournal.com/forum/ and ask your question and anything else you want to know about garage, shops, tools, heating, floors, etc.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by smitcat » Mon Jan 20, 2020 8:21 am

michaeljc70 wrote:
Sun Jan 19, 2020 4:22 pm
smitcat wrote:
Sun Jan 19, 2020 3:17 pm
dm200 wrote:
Sun Jan 19, 2020 2:23 pm
Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas
"Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:"
Of course gas needs a few other items when installing:
- source for gas
- flue and/or chimney above the roof peak
- non flammable barrier above heater and on the walls
All of these can easily add to the complexity and costs of utilizing natural gas.
FWIW - we currently have 9 water heaters between our home(s) and where we work. 2 are oil heated , 1 is gas and 6 are electric. I have replaced each one of them over the years and only required 'help' with the gas heater.
We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue.
"We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue."
Drywall is used here as well but the spacing for the heater and rating of the drywall varies for a gas heater.
Notable in this case there is no existing gas furnace and the OP does not intend to add one.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by White Coat Investor » Mon Jan 20, 2020 11:09 am

doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands. Before I start talking to a plumber, I'd like to be a little prepared. Should I be staying away from tankless heaters? I suppose my main goal is to save space in the garage (I will probably be installing a minisplit for heating/coolilng). The garage size is going to be around 26ftx28ft with an attic room and the bathroom downstairs.

Recommended options.....go tankless? Get a small water heater (40g?) and stash it somewhere under the stairs? Beef up my main house water heater (we are going to be replacing this soon) and run a pipe from house to garage?

Goals: Save space, save money....
Get one of these: https://gringosabroad.com/electric-show ... -shocking/

Hardly any space at all.
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by michaeljc70 » Mon Jan 20, 2020 11:18 am

smitcat wrote:
Mon Jan 20, 2020 8:21 am
michaeljc70 wrote:
Sun Jan 19, 2020 4:22 pm
smitcat wrote:
Sun Jan 19, 2020 3:17 pm
dm200 wrote:
Sun Jan 19, 2020 2:23 pm
Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas
"Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:"
Of course gas needs a few other items when installing:
- source for gas
- flue and/or chimney above the roof peak
- non flammable barrier above heater and on the walls
All of these can easily add to the complexity and costs of utilizing natural gas.
FWIW - we currently have 9 water heaters between our home(s) and where we work. 2 are oil heated , 1 is gas and 6 are electric. I have replaced each one of them over the years and only required 'help' with the gas heater.
We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue.
"We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue."
Drywall is used here as well but the spacing for the heater and rating of the drywall varies for a gas heater.
Notable in this case there is no existing gas furnace and the OP does not intend to add one.
True, but presumably their will be a plumbing vent already going to the roof. Most electric water heaters require a 240v line which is not standard in a garage. A shower in a garage is not standard so either way there will be additional requirements.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by sailaway » Mon Jan 20, 2020 11:29 am

Have you looked into propane tankless?

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lthenderson
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by lthenderson » Mon Jan 20, 2020 11:54 am

doss wrote:
Fri Jan 17, 2020 1:07 pm
I am looking at building a detached garage that will be about 50ft from the main house. I plan to have a bathroom with shower in the garage, but I am clueless about how to heat the water in the garage for showering/washing hands.
Do you live in a climate that freezes during the winter months? If so, are you heating the garage during the winter months to prevent pipes from freezing? If not, anything you put in for a water heater will need to be drained when not in use.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by smitcat » Mon Jan 20, 2020 11:58 am

michaeljc70 wrote:
Mon Jan 20, 2020 11:18 am
smitcat wrote:
Mon Jan 20, 2020 8:21 am
michaeljc70 wrote:
Sun Jan 19, 2020 4:22 pm
smitcat wrote:
Sun Jan 19, 2020 3:17 pm
dm200 wrote:
Sun Jan 19, 2020 2:23 pm
Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:

1. Natural gas is usually less expensive to heat the same amount of water the same amount of temperature
2. Natural gas heats the same size tank more quickly than electric - which can mean a smaller tank may be required for natural gas
"Having had both natural gas and electric water heaters, natural gas usually seems to have two cost benefits:"
Of course gas needs a few other items when installing:
- source for gas
- flue and/or chimney above the roof peak
- non flammable barrier above heater and on the walls
All of these can easily add to the complexity and costs of utilizing natural gas.
FWIW - we currently have 9 water heaters between our home(s) and where we work. 2 are oil heated , 1 is gas and 6 are electric. I have replaced each one of them over the years and only required 'help' with the gas heater.
We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue.
"We use drywall here...like the rest of the house. If you have a gas furnace they often share the flue."
Drywall is used here as well but the spacing for the heater and rating of the drywall varies for a gas heater.
Notable in this case there is no existing gas furnace and the OP does not intend to add one.
True, but presumably their will be a plumbing vent already going to the roof. Most electric water heaters require a 240v line which is not standard in a garage. A shower in a garage is not standard so either way there will be additional requirements.

'True, but presumably their will be a plumbing vent already going to the roof."
Maybe a vent and maybe not 0 but nothing close to a double wall gas heater vent.

"Most electric water heaters require a 240v line which is not standard in a garage."
All of our electric water heaters are 120 volt. But the OP Is installing a split HVAC unit so he will likely have 220 available.
In any case - where we are the design,permitting, space requirements, total installation costs are all much more expensive for natural gas.

"A shower in a garage is not standard so either way there will be additional requirements."
I have a shower in our garage - it really comes in handy.

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dm200
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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by dm200 » Tue Jan 21, 2020 10:02 am

Unless I missed it, the OP use of this space is unclear. Is it still to be used as a garage, or being converted to office or living space?

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by smitcat » Tue Jan 21, 2020 10:06 am

dm200 wrote:
Tue Jan 21, 2020 10:02 am
Unless I missed it, the OP use of this space is unclear. Is it still to be used as a garage, or being converted to office or living space?
Garage.

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by ddurrett896 » Tue Jan 21, 2020 10:23 am

doss wrote:
Fri Jan 17, 2020 1:07 pm
Recommended options.....go tankless? Get a small water heater (40g?) and stash it somewhere under the stairs? Beef up my main house water heater (we are going to be replacing this soon) and run a pipe from house to garage?
I would not run a hot water line from the house to the detached garage. Run cold then do a small tank or tankless. Either works, I'd do a small 120v under the sink unless you plan on a large consumption of hot water out there.

Go check our garagejournal.com

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by sjt » Tue Jan 21, 2020 10:32 am

Cubicle wrote:
Sat Jan 18, 2020 1:38 am
My biggest concern would be water supply freezing & the drain line back to house. But anyways:
x2 - OP what climate do you live in? Is the garage going to be above freezing at all times? Could run into pipes bursting if they freeze -
"The one who covets is the poorer man, | For he would have that which he never can; | But he who doesn't have and doesn't crave | Is rich, though you may hold him but a knave." - Wife of Bath tale

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Re: Detached garage: Recommended ways to heat water for shower? Save space and money?

Post by michaeljc70 » Fri Feb 14, 2020 1:39 pm

I saw this for the first time today. Not sure it was mentioned above. It is a shower head that heats the water. $105. Warmer climates only.

https://www.homedepot.com/p/IHeat-2-5-k ... fx-9TyPQA0

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