In the home stretch on my 40x60 build and looking at water heater options. It has a full bathroom with shower in it and a slop sink. The reality is the shower will probably rarely or never get used. It was mainly installed because the layout left enough room that it didn't make sense to leave the dead space. Because you just never know. I plan on having the ability to run hot water to my outside spicket for use with my pressure washer. But that aswell may be very infrequent. Been looking hard at tankless units specifically rheem rtex-18. Really like the ability to adjust the temp on demand. When i need hot water im gonna need a decent supply but when i don't seems a little wasteful to be heating 30-50 gallons for basically no reason plus there space savings. Does anyone have any specific experience or recommendations. Thanks in advance
Water heater
- Thread starter Jking24
- Start date
Notgrownup
Well-known member
I switched to a whole house rinnai gas unit and like it but for a shop I really would consider a smaller electric unit. No waste until you use it.
Not fan of tankless.......but.........for this shop application with little use it would be perfect.
There’s big difference in tankless and point of use water heaters in the capacity for temp rise and gallons per minute. Of course the power needs of the units is huge.
Endless hot water is not easy.
Point of use heater might be 120v 15 amp ( similar to iron or toaster). 2.5 gallon 7 gallons recovery per HOUR.
Typical smalltankless:
Reheem Performance 24 kw Self-Modulating 4.6 GPM Electric Tankless Water Heater
Capacity varies with inlet water temperature.
Requires 3 x 40 AMP double pole breakers. Max power 100 amps
$522
Hand washing and sink use is no issue with just about any unit. Even a small under sink might work. Hose use and pressure washing is completely different. It’s all about 4-5 gallons per minute and the water temp rise needed to get the job done. 80-85* water is not worth the effort when 120* is required.
A large capacity tankless with a decent temp rise for the gallons used might need 3 60 amp 240v breakers. Does the shop have that capacity ?
Same for NG units, large capacity heater needs a large gas line. When installed in the home the gas meter usually is upgraded and often the pipe as well.
My shop has cold water. The attached garage has hot and cold connected to the homes water heater. Great for car washing in the winter, pressure washing grimy stuff etc. Location not as convenient as the shop but low cost and 130* water is worth the trip. Garage hot water was $140 all in. Looked at the shop hot water, maybe down the road. My shop has 100 amp service of the home. NAT gas line is supply is 1” with 1/2” distribution line in the building.
Hand washing ( hot water) in the shop was not a priority. Especially for point of use heater.
There’s big difference in tankless and point of use water heaters in the capacity for temp rise and gallons per minute. Of course the power needs of the units is huge.
Endless hot water is not easy.
Point of use heater might be 120v 15 amp ( similar to iron or toaster). 2.5 gallon 7 gallons recovery per HOUR.
Typical smalltankless:
Reheem Performance 24 kw Self-Modulating 4.6 GPM Electric Tankless Water Heater
Capacity varies with inlet water temperature.
Requires 3 x 40 AMP double pole breakers. Max power 100 amps
$522
Hand washing and sink use is no issue with just about any unit. Even a small under sink might work. Hose use and pressure washing is completely different. It’s all about 4-5 gallons per minute and the water temp rise needed to get the job done. 80-85* water is not worth the effort when 120* is required.
A large capacity tankless with a decent temp rise for the gallons used might need 3 60 amp 240v breakers. Does the shop have that capacity ?
Same for NG units, large capacity heater needs a large gas line. When installed in the home the gas meter usually is upgraded and often the pipe as well.
My shop has cold water. The attached garage has hot and cold connected to the homes water heater. Great for car washing in the winter, pressure washing grimy stuff etc. Location not as convenient as the shop but low cost and 130* water is worth the trip. Garage hot water was $140 all in. Looked at the shop hot water, maybe down the road. My shop has 100 amp service of the home. NAT gas line is supply is 1” with 1/2” distribution line in the building.
Hand washing ( hot water) in the shop was not a priority. Especially for point of use heater.
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59 wagon man
Well-known member
the rheem is built by Niagara industries in Miami . maker of titan tankless heater. look at the n-120
I think a tankless would be ideal ... I'm not a huge fan -- but, I have one for my outside shower at the beach house. May not get used for two weeks and then -- non stop all afternoon.
You have the same usage .. when endless hot water is the need -- there is nothing better. I happen to also have a hot/ cold tap at the shower .. so I can dial in nice warm water for all kinds of cleaning around the house using a hose.
A typically pressure washer does not use all that much GPM -- I have no problem using my 6hp excel unit on mine.
I have a gas unit -- but the electrics are fine if you have the power. Don't oversize it
You have the same usage .. when endless hot water is the need -- there is nothing better. I happen to also have a hot/ cold tap at the shower .. so I can dial in nice warm water for all kinds of cleaning around the house using a hose.
A typically pressure washer does not use all that much GPM -- I have no problem using my 6hp excel unit on mine.
I have a gas unit -- but the electrics are fine if you have the power. Don't oversize it
HoosierBuddy
Well-known member
To build on what yeldogt said, although I don't have it at home, at work we have a hot and cold line running to our hose hydrant valve....so you can run cold water, warm water or hot water through the hose. It is handier than you might think, especially with the floor drains.
I mean...if you have the hot water readily available...it's something to consider.
I too would normally NOT recommend a tankless electric heater due to the operating cost difference over gas...but as you point out it won't get used a lot...so it makes perfect sense in your application because of the simplicity and cheaper up front cost.
Phil
I mean...if you have the hot water readily available...it's something to consider.
I too would normally NOT recommend a tankless electric heater due to the operating cost difference over gas...but as you point out it won't get used a lot...so it makes perfect sense in your application because of the simplicity and cheaper up front cost.
Phil
With a low flow shower head, a 10 gallon water heater will work, many decades ago I lived with one and could not change the shower head so learned to take a really quick shower , too bad that habit was unlearned. A tankless electric WH has a very high power demand so I would not recommend one but gas would be a good choice particularly if natural gas was available.
It's not going to be enough for a power washer -- or really heavy cleaning.
I have a 10 gallon 120 in my outdoor kitchen -- we have never run out even using for a big party. My neighbor has a 5 gallon and it will start to go warm if someone is not mindful of the limitations.
The key with a tank is illustrated above: Do you get the 5 and understand the limitations? My guess is a 5g would do 95% of my needs ... it's also much faster to reheat with 1/2 the water. With the 10g -- it's got to handle 100 percent of the load ... because the recovery is too slow.
This is the mistake people make in a residence. You want the unit to have enough for each event. Going too big can actually cause issues ...
Steve W.
Well-known member
I have a Bosch tankless in the house that runs on natural gas.
I don't have gas running to the shop, so I installed a Rheem RTE 13 electric unit.
Only feeding the sink in the half bath and the slop sink, and using 1/2" copper water line. Runs on 240v, rated to pull 54 amps.
It gets the water hotter than I need (most of the time), but it's nice to have.
.
I don't have gas running to the shop, so I installed a Rheem RTE 13 electric unit.
Only feeding the sink in the half bath and the slop sink, and using 1/2" copper water line. Runs on 240v, rated to pull 54 amps.
It gets the water hotter than I need (most of the time), but it's nice to have.
.
If you're going to put in a regular water heater and you've got the space just go with a 40 gallon. Barely costs more than 6 or 10 gallon. Big tank doesn't really cost anymore to keep warm either.
If it was just for a sink then a little point of use would be perfect. But if you want to wash with it and maybe a shower I would just do the 40 and be done.
If it was just for a sink then a little point of use would be perfect. But if you want to wash with it and maybe a shower I would just do the 40 and be done.
Thanks for all the replies. Power is not a issue the garage has a 200 amp service and the unit will be really close to the panel so wiring cost would be minimal. I am installing radiant heat in the floor that system will use a tankless propane water heater. i had contemplated using the same unit for both needs via a in line heat exchanger but i don't really want any efficiency loss in the floor system and i also don't want to be dependent on propane for everything. So me initial thoughts were to keep the two systems separate. Also the plan was to finish the radiant later in the year when the budget recovers a little. So their is currently only electric. Im not completely against two propane tankless units but that is something i haven't really looked into at all yet
I would put them together -- why two? The floor will have no issues being off for the short time you are using the water.
I was under the impression that when used for both the floor gets heated from the exchanger not the unit and that is why i mentioned a efficiency loss. But I'm gonna look into it thanks
Sounds like a tankless is done deal........in this application.
With low usage, but high demand when used, get a large unit greater than 100 amps, has lower install cost compared to propane and cost of operation would not be a factor.
You likely know this:
As far as using tankless for in floor heat there are important considerations to make it work. The return temperature of the water is one, is critical and must be managed.
With low usage, but high demand when used, get a large unit greater than 100 amps, has lower install cost compared to propane and cost of operation would not be a factor.
You likely know this:
As far as using tankless for in floor heat there are important considerations to make it work. The return temperature of the water is one, is critical and must be managed.
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If you already have the propane for floor heat, why not a combo boiler that can do both hot water and heat? Then do a small 5 or 10 gallon electric for normal sink use.
Or a 40 gallon propane water heater? A power vent wouldn't use much energy.
Or a 40 gallon propane water heater? A power vent wouldn't use much energy.
sberry
Banned
You really want 120A service coming on for every hand wash?
Once your decide you want ( need) hot water 120A or propane ......tank or tankless....makes little difference. Tankless wins if the use is low or infrequent. Other wise......grand scheme each has their merits and issues already mentioned.
This does sound like a budget build so:
Some where along this decision tree......in for a penny in for pound.
sberry
Banned
If a guy has lp why sock it on the electric? That is a gift. Gas is great during power outage.
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Most of the on demand units are staged to my knowledge so while capable of 120amp the unit would probably be more in the 40 amp range for hand washing. I was leaning away from gas because i don't plan on finishing the floor heat until later in the year. So their currently is no gas installed yet