Freshwater system
These are the actual components as laid out on the living room floor.
This diagram does not totally accurately represent the system, but… it’s so simple and clear, that it’s the one I’d like to start this conversation with.
I have all of the same components as shown above, except for the check valve as is shown. I have 2 of those, but they will be located as shown in the first photograph, instead of as in the second diagram.
These components include:
- 35-gallon freshwater tank. I’m teetering between food-grade hdpe and stainless steel. The former is a lot cheaper and would lend itself to maintenance by replacement down the road, while the latter is expensive, but probably a good investment in our health and water taste.
- pex tubing (blue, and red)… I figure plastic in the lines doesn’t matter as much as it does in the tank… it’s there for a much shorter duration, right? Spending less on it also means I can do “maintenance by replacement” on it, too, right? I hate that mentality, but…
- strainer and pump
- city water inlet… still shopping
- double-wall flat plate type heat exchanger for a water heater
- sink fixture… maybe this one… but, still shopping a little bit
- 1.8 gpm shower head and shower restrictor valve
Some additional accessories include (my local Ace had better prices on Sharkbite stuff than online vendors):
- 5 Sharkbite tees for purposes of: joining tank and city water, splitting off the cold line to the water heater, providing a bypass around the heater to the thermostatic mixing valve, and tee-ing off the hot and cold lines for the first of two fixtures
- 5 Sharkbite elbows for some installation flexibility
- 2 brass elbows for connecting to the heat exchanger
- 2 check valves
Not shown, but present in my system, after the water heater is a:
In order to install a thermostatic mixing valve, one tees off of the cold supply that goes to the water heater and then provides that and the hot water exiting the water heater to it. I will probably set the thermostatic mixing valve (TMV) pretty darn low such that I achieve the best multiplier possible… e.g. use more cold water for a given amount of hot water, thus slowing down the flow-rate on the cold side of the heat exchanger, which will improve its performance and delay the draining of thermal storage out of the hot coolant system. No sense in draining energy out of the coolant system, just to bring it down to a useable temperature. I’m not sure I’m really even thinking about this correctly, but I figure that I’d rather have 110F running through my pipes than 140F+ anyway, and it increases end-user safety, so… seems like the right choice, regardless.
I think I’ll make the TMV connection using:
- Another 1/2" sharkbite tee
- (3) 1/2" push-fit x 1/2" mpt connections for… connecting to the water heater inlet, the tmv cold inlet, and the tmv mixed outlet
- A 1/2" male x 1/2" male lead-free nipple to connect the 1/2" female thermostatic mixing valve to the 1/2" female brass elbow coming off the water heater exit
