Water Heater Tank Size

[wewiserangers]

I have a utility sink in my shop, full bathroom with shower and a kitchen area. Trying to decide what size electric tank water heater. This is all in my shop so it's all an occational use area really. Tankess is not an option due to the power requirements.

I need it to work but not be overkill.

 

[sparky 1971]

Anything less than 30 gallons could lead to a cold shower. My first house had a 30 gallon electric water heater and every morning over the winter I would be in the shower until ice cubes were coming out of the head and it didn't seem to take very long. Personally, I'd put a 40 gallon in and forget about it.

 

[Stuart in MN]

Figure out how many GPM will come out of your shower head, multiply that by how long it takes for you to take a shower.
If it weren't for the shower you could probably get away with a 5 or 10 gallon heater.

 

[The Cobbler]

how long of a shower do you want?
I can (Navy) shower with a 6 gallon set fairly high temperature and throttling the water down when shampooing or sudsing up . shaving & brushing teeth usually included

 

[Vtor]

Tank size and recovery time - need to consider both. If recovery time is short, may be able to make due with smaller tank.

Went tankless.... never going back.

 

[PoorUB]

If you want to use the shower regularly, get a 40 gallon. Also, if you shop around you will find a 40 gallon will be competitively priced to anything smaller worth considering.

 

[jblnut]

I have a 6gal in my shop and I can shower easily with it. Takes a bit to recover but isn’t an issue. You can’t sing a musical while showering but you’ll get clean before it gets cold.

 

[JuncleJohn]

Most campers only have 6 gallon water heaters. Plenty of water to shower if you don’t let the water run. Why pay to heat 30 or more gallons for occasional use?

John

 

[finn]

Sort of depends on where you live. It’s a little exaggeration to say our forty gallon tank Is overkill in our Tucson house. Our Michigan house has a 40 gallon hybrid and it’s more than adequate for the two of us, or even when the kids show up. Growing up in a family of eight, I recall frequently running out of hot water even with only one shower in the house, especially on wash day, with a forty gallon tank.

My mom’s Florida condo had a thirty gallon, I think, and it was adequate for my family of five, plus my folks.

My three gallon at the shop barely gets me through washing the dishes. Works ok for most tasks, but I would hook up the DHW loop of the propane boiler if I wanted to add a shower.

Aren’t most camper tanks propane fired? Electric has slower recovery. I think most small electric are 120 v.

I would shoot for a 20 or at most a thirty gallon tank for a shop with the understanding your showers aren’t going to be half hour affairs.

 

[rlitman]

Most campers only have 6 gallon water heaters. Plenty of water to shower if you don’t let the water run. Why pay to heat 30 or more gallons for occasional use?

I've gotten my full quarter's worth out of a coin op shower, so "plenty" is all relative.

But there's nowhere near enough info here to make an informed decision. What climate is this shop in? What are the power limitations that prevent a tankless from being used? How clean is the air in the shop? Would a heat pump water heater make sense?

 

[67King]

NOt what you asked, but since you mentioned electric, we have two heat pump water heaters. Highly recommend. Tons less expensive than conventional ones.

 

[Shiftless]

NOt what you asked, but since you mentioned electric, we have two heat pump water heaters. Highly recommend. Tons less expensive than conventional ones.

For a high usage situation I’m sure they use less electricity than conventional water heaters. But the higher initial cost, including higher installation coast unless you’re gonna DIY, make it a decision worth considering for a shop where hot water use is much less than for a house. Payback time also depends on the local cost of electricity and the projected life of each unit.

 

[JohnX14]

Heat pump water heaters are one of those 'systems' that only pay back if you get a rebate. Otherwise the cose difference doesn't justify it, especially with low use.

I'd put in a 40 gallon electric and not look back. Standing losses aren't enough to matter, at least for me.

 

[KentheMailman]

Heat pump water heaters were the bomb when we received the full tax credit years ago. Electricity costs are $10-11 a month for the two of us full time in East Texas. But $2,500 for a 50 gallon water heater for occasional use - maybe not.

 

[dave*99]

how long of a shower do you want?
I can (Navy) shower with a 6 gallon set fairly high temperature and throttling the water down when shampooing or sudsing up . shaving & brushing teeth usually included

I had to read that twice.

 

[nadogail]

My workshop has a three gallon, 120 Volt water heater, it is sufficient for washing hands and cleaning paint brushes.

 

[rlitman]

I had to read that twice.

We don't shame people here for their hairy teeth.

 

[dave*99]

I wouldn’t dare.

 

[Overboost44]

I have a 40 gal in my house. With 4 of us here, never had a problem unless there was a case of consecutive showers and that maybe happened 3 times in 7 years.

 

[finn]

I miss the old days. Between the Lowe’s sale price and power company rebates, I paid $ 50 for my first hybrid water heater and a second one was free after the rebates when they improved the program and I bought another one one for a different house the next year.

I think that was about ten years ago, and I shouldn’t say it out of fear of Jinxing myself, but they’re both still running fine.

 

[Bert_]

Smaller than a 40 gallon doesn't save much money.

 

[PoorUB]

I'm proud of you guys that that can shower on a cup full. I enjoy a good shower and need more than six gallons to take a shower!
We had a forty gallon electric and my wife and I couldn't take back to back showers, unless you don't mind rinsing in cold water. Whomever went second waited a half hour. I probably could do it on a 30 gallon, but we are just splitting hairs at that point.

 

[finn]

I'm proud of you guys that that can shower on a cup full. I enjoy a good shower and need more than six gallons to take a shower!
We had a forty gallon electric and my wife and I couldn't take back to back showers, unless you don't mind rinsing in cold water. Whomever went second waited a half hour. I probably could do it on a 30 gallon, but we are just splitting hairs at that point.

I’m sort of wondering what you’re doing in there.

But then again, maybe I don’t want to know.

We take two showers simultaneously (in different bathrooms) and have never run out of water with any of our 40 gallon electric, hybrid, or NG water heaters, and that includes living on cold well water.

 

[PopcornSutton]

My first house had a 30 gallon heater. With two of us, we never ran out. Fast forward to present, in a different house that has a 50. I'm waiting for the day when it springs a leak or the elements go, and I'll put another 30 in. My wife uses way more water than me to shower with her long hair, but I doubt she would run out. Both showers have 2 gal restriction washers. I turn the water off to soap up, a habit when I was growing up when we only had a shallow well. I see no point in heating more than needed.

 

[dcg9381]

Figure out how many GPM will come out of your shower head, multiply that by how long it takes for you to take a shower.
If it weren't for the shower you could probably get away with a 5 or 10 gallon heater.

Standard RV size for a water heater is about 5 gallons. 10 gallons if you've got a "luxury" monster.
Another factor on "how much water heater do I need" really depends on the incoming ambient temp of the cold water side and the temperature setting on the water heater.

 

[WE3ZS]

Standard RV size for a water heater is about 5 gallons. 10 gallons if you've got a "luxury" monster.
Another factor on "how much water heater do I need" really depends on the incoming ambient temp of the cold water side and the temperature setting on the water heater.

Actually the “standard” sized RV water heater is 6 gallons and the “luxury” sized one is 12 gallons. We had two trailers with the 6 gallon units and would sometimes run low on the hot water during the third back to back shower, but that could be avoided if we ran both the electric and gas heating modes for a more rapid recovery time. Our current fiver has the 12 gallon unit and we have not had a hot water shortfall in it yet, even doing laundry while showering back to back. Of course we run our water heater hot enough to have to mix it with cold water to have a good shower temp, which obviously stretches the available usable “hot” water.
For the OP’s occasional use scenario I would think that a small 20-ish gallon well insulated water heater with the temp set more to the hot side would be plenty.

 

[dave*99]

I’m sort of wondering what you’re doing in there.

But then again, maybe I don’t want to know.

Maybe get rid of that shower head.

 

[NUTTSGT]

If you yo to the big box store, a 40 is probably going to be the cheapest choice.

 

[JohnX14]

I grew up with an 80 gallon electric with a family of 5. Pops turned the temp way up, and we'd still run out or run cooler. Of course all of us showered in the morning. I'm sure they weren't water saver shower heads, but I don't know how 2 ppl. manage to shower with a 40 gallon.

 

[Sumboodie]

Figure out how many GPM will come out of your shower head, multiply that by how long it takes for you to take a shower.
If it weren't for the shower you could probably get away with a 5 or 10 gallon heater.

We have a 2.5 gallon at the shop and it handles washing hands and a washing machine fine. Granted not both at the same time.

I was very surprised the tiny thing under the counter was it.

 

[American Locomotive]

If it's an occasional use thing, and only one, maybe two people tops would ever take back-to-back showers, I'd just get a small 30 (maybe 40 gallon) electric water heater.

Tank water heaters have pretty surprising standby losses - about 40-50 watts continuous. That'd be over $120/year in electricity in my area. You want to minimize standby losses, so a heater with a smaller exterior surface will be better. Wrap the thing in extra insulation (they sell special jackets) and insulate the pipes going in and out of it. You may also want to consider putting the water heater on a timer, or on a relay with the lights on the shop.

Heat pump water heaters are one of those 'systems' that only pay back if you get a rebate. Otherwise the cose difference doesn't justify it, especially with low use.

I'd put in a 40 gallon electric and not look back. Standing losses aren't enough to matter, at least for me.

In New England, a heat pump water heater will pay for itself in 2, 3 years tops compared to a straight resistance electric heater. That's with no rebate, if you get a rebate, pay-off will be less than a year. I've installed a HPWH for a few people now, and it's pretty much an instant $70-90/month reduction in electric bill.

But a shop hot water source that'd rarely be used, it probably wouldn't make sense though.