I built a wood shop with a small bathroom that has a standup shower and one sink. Is a 20-gal electric water heater enough for the occasional shower and of course the sink? The one I am looking at is the Rheem Commercial Point of use 20-gal 3kw model (# EGSP20 240 Volt 3kw POU). Thanks in advance!
Electric Water Heater Advice...
- Thread starter dmbarney
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Do you want me to break it down as a science for you ? Or just tell you what I would do ?
With a thermostat setting of 130 and a shower head that flows 2.5 gallons per minute and a incoming cold water temp of 50 degrees and a shower temp of 105 degrees you’ll get about a 7 minute shower then it drop off fast to 50 degrees after 7-11 minutes.
But for the price of a 20 I believe you could buy a 30 or 40. You could turn the temp down if you wanted if you had a bigger heater.
But for the price of a 20 I believe you could buy a 30 or 40. You could turn the temp down if you wanted if you had a bigger heater.
In my dad's welding shop, he had a 40-gallon gas water heater that was kept at a relatively low temperature setting 99% of the time. He knew in advance when he was going to use more hot water than the "warm" water from the heater would provide, so he would turn up the temperature and have plenty of hot water for that short period of time.
If you have poor quality water, turning up the water temperature on an electric water heater will cause quicker mineral buildup on the elements. But Twowaxhack knows more about electric water heaters, so he may provide additional insight into this suggestion.
In any case, it depends on how long you want to shower if a 20-gallon water heater will be large enough.
If you have poor quality water, turning up the water temperature on an electric water heater will cause quicker mineral buildup on the elements. But Twowaxhack knows more about electric water heaters, so he may provide additional insight into this suggestion.
In any case, it depends on how long you want to shower if a 20-gallon water heater will be large enough.
I'll take both please. thanks
How much water do you want your shower head to flow per minute ?
How hot do you want to heat the water ?
What’s your average cold incoming water temp ?
What temp do you shower at ?
How long of a shower do you want to take ?
But yes, it’ll work fine if you start off a shower with a full tank and you take a 5 minute shower.
Twowaxhack, looks like Rheem has a 30gal low/compact profile that is actually $200 cheaper. I kind of need to stick with a compact one because of space. Any recommendations on brand? Also I played with the thought of either gas or electric insta-hots but I think that is overkill for what I need.
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More than adequate.
I had a summer cottage with a
10 gallon water heater which gave
a nice hot shower for maybe 5 minutes.
And being so small, on a 120v circuit
rated for 16amp if I recall correctly,
if you ran the water long enough
to turn hot into warm, then stopped
using, it would reheat
back to hot in around 15min.....
30min from a cold start.
Soapbox tangent from observing a spoiled
millennial-kid family on a 40gal heater:
we should all teach our kids that a
10+ min shower you can get from
a 30+ gal tank is a luxury they should
learn (the cost of) (not to expect).
Hard to teach, without limiting/suffering.
And not every diverter/control setup has
volume/flow control (most do, right?)
Aggie83
Well-Known Member
I have had excellent service with a tankless heaters used for a single bathroom. Cost for electric is about $200 for 11kw. Smaller than a briefcase and hangs in the wall. Typically need a 40 amp breaker.
We should also teach our kids that Old men start wars and send young men to fight the wars.
11kw Rheem tankless requires a 60 amp breaker.
Or at least a 50 amp!
I was going by what Rheem says it requires.
Yeah I was looking at them, but I am running out of slots in my panel. Still need to wire for a table saw and dust collection.
Bird Doo Head
Well-Known Member
Depending on your load center, you'll most likely be able to make breaker space by using tandem or quadraplex circuit breakers. (Slang: Piggyback & Quad) Or, install a sub panel for extra space to use later.
Lower Cost Electricity:
Your utility may offer a Water Heating Rate. Not only is the cost-per-kilowatt lower, it solves your circuit breaker space problem because the heater is fed from a separate meter.
Tankless & Heat Pump Water Heaters:
A tankless, on-demand heater may save you money in the long run because there is no tank of water that gives off heat to the (cold?) garage between uses.
A heat pump style can yield more hot water per kW-h than a standard type because it is moving heat from the surrounding air to the water.
A good article is at: Which Water Heater Is Right for You?
Rebate?
There might also be a federal or state tax credit or utility company rebate for a tankless or heat pump style heater.
I know that there is a federal one in 2023 for heat pump style of 30% of the total project cost, up to $2,000.00 max credit.
Paul
