Which hot water tank size?
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Jimbo
Plumber
A 30 gallon tank would serve a shower for one person, with very little other demand in terms of sinks, dishwashers, laundry, etc. Around here, the city will approve a minimum 30 gallon tank for a studio or 1 BR apt.
As far as the tub, you have problems. A 30 gallon tank will deliver 21 gallons of water at a temp. not less than 20º below set point. ie if it is set at 130, you could get 21 gals. of water at least 110º. A 50 gallon tank gives you 35 gallons. ( This is the 70% rule)
The only thing which will give you unlimited gallons of hot water is a tankless unit, but at a very slow GPM rate, depending on size of unit.
Tell us more about your house, how many bath, how many people,etc. If the tub is an important use, and/or you do lots of laundry, you are a candidate for a very large GPM tankless, or an 80 to 100 gallon tank.
As far as the tub, you have problems. A 30 gallon tank will deliver 21 gallons of water at a temp. not less than 20º below set point. ie if it is set at 130, you could get 21 gals. of water at least 110º. A 50 gallon tank gives you 35 gallons. ( This is the 70% rule)
The only thing which will give you unlimited gallons of hot water is a tankless unit, but at a very slow GPM rate, depending on size of unit.
Tell us more about your house, how many bath, how many people,etc. If the tub is an important use, and/or you do lots of laundry, you are a candidate for a very large GPM tankless, or an 80 to 100 gallon tank.
Jadnashua
Retired Defense Industry Engineer xxx
You'll get (as noted above) about 70% of the tank's volume into your tub before it cools off more than you'd want. If you want to fill up that tub with hot water, you'd need approximately 65-70 gallon tank. Some tanks recover quicker, and can supply a bit more than that 70%. Now, that doesn't mean that you would always fill that tub up to the max, so smaller MAY suffice. It also will depend on how cold your incoming water is...if in a cold climate in the winter, the recovery could be much slower and the dilution factor would potentially mean you don't get all 70%, either.
Master Plumber Mark
Sensitivity trainer and plumber of mens souls
elctric water heaters--go big
you might get by with a 50
but you might as well get either a 66 or an
80 and be done with it.. the cost difference is nominal.
set it on medium and youwill be happy
you might get by with a 50
but you might as well get either a 66 or an
80 and be done with it.. the cost difference is nominal.
set it on medium and youwill be happy
Master Plumber Mark
Sensitivity trainer and plumber of mens souls
66 and 80
in this region the 80 is only about 30 dollars more than a 66
I tell them if it fits .......go big.....
in this region the 80 is only about 30 dollars more than a 66
I tell them if it fits .......go big.....
Gary Swart
In the Trades
Can you have too much hot water? It's nice to have a reserve even if you seldom if ever use it. Go big.
Lakee911
I&C Engineer (mostly WWTP)
If its for the master suite only, why not plumb it in series with the other one? More capacity then, right?
Jason
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water
They may not have access to an existing hot water line to permit a series/flow through connection. But in any case, a 30 gallon electric is almost useless for anything other than a one person apartment and short showers. A 50 gallon would be marginal, but anything larger will have a disproportionately higher cost.
They may not have access to an existing hot water line to permit a series/flow through connection. But in any case, a 30 gallon electric is almost useless for anything other than a one person apartment and short showers. A 50 gallon would be marginal, but anything larger will have a disproportionately higher cost.
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