New construction - water heater type/location

[jimpargolf]

I am planning on starting construction of a ranch style home later this year and my concern is having hot water without waiting so long because of the distances involved. All the main bedrooms are at one end of the house and the kitchen and a bathroom are at the other end. Approximately 85' apart. All electric house and will have solar. Will be net zero here in Southern California. My option I've come up with is to use 2 Hybrid Hot Water Heaters ( each one would located at the ends of the house). This gives me hot water very quickly since I can just do home runs (PEX) to each fixture (they'll only be on average about 15' away). Of course, I'd have to buy 2 units and they may last 10-15 yrs before replacement. I would rather have only one unit but if I do, can I do a recirculation system? No manifold? Trunk and branch the option? I've looked into Electric Tankless but they require too much power (going solar - trying to be net zero).

 

[Dana]

Slab on grade, crawlspace, or basement?

Is it a full bath w/tub & shower by the kitchen, or just a half bath toilet & wash basin?

The laundry is near which end?

 

[Sponsor]

 

[jimpargolf]

Slab on grade.
It's a shower/toilet/sink. No tub.
The laundry room is by the bedrooms at the other end of the house.

 

[jimpargolf]

I don't think the shower will ever get much use. IMO. Might get some use as a dog wash area.

 

[Dana]

Seems like a heat pump water heater in the full bath, and recirculation system to serve the kitchen would make the most sense than two full sized. tanks. Bathing is typically the highest volume and highest flow use, so that's where the heat-pump/hybrid water heater should live.. Half inch plumbing on the recircualy oop to the kitchen & half-bath would abandon only half the hot water volume of 3/4" plumbing, and the higher flows of fatter piping aren't needed.

But most of the hot water use in the kitchen is in small volume draws- less than a gallon at a time, and it would abandon about a gallon of hot water in the line if drawing from the far end of the house. If the shower is never going to see regular human use it might be more efficient to use a small ~15-20 gallon standard electric tank on that end, with short home-runs to the sink, dishwasher & washbasin. In warmer climates it's possible to get a single decent length shower out of a 15 gallon tank, but not not a long shower (or multiple showers in rapid succession.)

If going the recirculation loop route, keep the plumbing entirely inside the insulation boundary of the house, but not under the slab (where repair/service is impossible.

Heat pump/hybrid water heaters need a lot of air volume to work well, and can be fairly noisy. Hopefully those aspects have been thought out(?) for placement of the unit on the bedroom end.

 

[jimpargolf]

Thanks for the reply Dana. I like the idea of a recirc loop and only having one hot water heater. The one negative on location of the water heater is that the bedrooms use water 2x/day - once in the morning and once in the evening. This would make it better to have this at the recirc. end than the other area of the house. The kitchen / bathroom at that end is used throughout the day (at least based on our usage) Make sense?
Right now, I have a much better/quieter location (utility room/unheated/access from outside) for the hybrid water heater right by the laundry room (between the 3 bedrooms). The location on the other end of the house is not as good
(noise could be an issue but could always move it to garage) Kind of like the idea of a small tank you mentioned. That is a definite possibility.
When you mentioned having the plumbing inside the house - are you talking about the recirc. loop only or all the lines?
And is PEX good for the recirc loop?

 

[WorthFlorida]

You're going to the new trend, solar panels and I assume electric. Someone I know just has 23 electric panels installed on his roof at a cost of $12,500. His first net electric bill was 300KW credit ($9 bill) and he has an electric car. We are in the east area of Orange County, Florida.

I think this would be a good new forum to add this site for "Electric Solar Panels".

 

[Dana]

Putting the HPWH in the laundry area with a recirculation to the bedroom end works. Use 3/4" for the supply to the remote bathroom, since tub fills will need a maximum flow, but the return line of the recirculation can be 1/2" (or use the cold supply line, if you don't mind a slug of tepid water in the cold water at kitchen.)