I’m building a house that’s “L” shaped with 3 bathrooms at the end of one leg of the “L” and a kitchen/half bath/Laundry in the other leg. So I need hot water at two locations about 100′ apart.
My plan was to put the electric water heater right near the kitchen/half bath/laundry area to provide hot water pretty quickly to those areas and then run a recirculation pump with a dedicated to the other side of the house (100′). I’m using 3/4″ pex for main line connected to manifolds with 1/2″ pex running to each fixture. But I’m wondering if this 100 feet is too far and subsequently cool the hot water too much by the time it gets there. Which will make the recirculation pump run non-stop. I’d probably insulate the pipe with some pipe insulation which should help. Any thoughts???????
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Ever consider two small heaters ... rather than a single large one?
If you're building a house from scratch and you're using electric water heaters, you might as well plan on two heaters. This will be the most efficient scheme, and the lowest maintenance.
You don't say where you are, but in moderate climates the heaters can be placed in the attic, if space is a problem. In other climates it should not be too difficult to set aside a small closet for a water heater, since the floor layout is still pliable.
I'm no fan of electric water heaters, but gas isn't available everywhere.
100' is really not that far, I come from the commercial side & 100' & longer runs is quite common for us.
I do like the idea of two smaller heaters, instead of one big heater for this particular scenario.
If you do decide to run with two I would run a line in-between the two for emergencies if one should happen to fail------ pex is pretty cheap security.
Thanks for the info....but to throw another twist to this story. I'm running two geothermal heat pumps (3 ton and a 2 ton) in a conditioned crawlspace which is providing most of the hot water. But I guess I could hook up each geothermal unit to a separate water heater. I'd just have insulate the supply line from the heat pump to the water heater since they won't be right next to each other.
In that case I wouldn't.
Running pipes to a remote storage tank is no more efficient than having the storage tank next to the heat pump & running pipes to a remote fixture.
A bunch of smaller tanks will lose heat faster than one big tank.
Using a hot water maker ( heat exchanger) from a heat pump or any other source, I would have a central storage tank & utilize a re-circ system.
Instead of using a thermostatic control, I would use a timer control so that it is circulating during the peek times of usage.
Insulating all hot water lines will help slow down heat loss.
“The Hand of providence has been so conspicuous in all this, that he must be worse than an infidel that lacks faith, and more than wicked, that has not gratitude enough to acknowledge his obligations.” —George Washington
If you can get rid of the long pipe from heater to fixture then do so! I have 45' of 1/2" pipe from heater to fixture in the kitchen and it takes a while to get hot water!
Electric water heaters are cheap to buy and insulation is the only thing that pays for itself from day one, so try to aim for more efficient and not bigger to compensate.
The answer has been given in this forum previously. I best idea that I have ever heard is to install a two gallon electric water heater in series with the hot water line running to the remote bath, very close to the remote bath. When a hot water tap is opened, water will be instantly available and before that water runs out the long line will be delivering hot water to the two gallon tank preventing it from going cold. Two gallon water heaters run on 110VAC power so the installation is very straight forward.