NiHaoMike, thanks again, I will try to make it clear.
The 120 gal DHW / Buffer tank is a Thermal accumulator, it will recieve heat from either the boiler or solar via this new heat pump. It has HX
to seperate the nasty boiler / radiant water from the potable DHW.
Heat can flow through this HX in either direction as required. The boiler will have long Eff. burn times. The zones can sip heat out as required without firing the boiler. The boilers only customer is the aqustat on this tank.
The 1,000 gal solar storage tank will be burried outside the basement.
It's temp. will vary quite a bit, possibly from 180* when there has been good sun & weather down to 35*
It will have a 300' loop of 1" pex in the top that will preheat the well water coming into the 120 gal DHW / buffer tank on any DHW draw. well water is just over 40*
There is also a 2nd HX loop in the top of the solar tank of O2 barrier 3/4" pex that will provide heat directly to the radiant floor system, via a Taco ODR controlled TMV which provides appropriate temp. water to a Grundfos Alpha pump to whatever zone of the hydronic floor that needs heat. I will use this source of heat whenever the solar tank is above 80*
When the 1,000 gal solar tank is below 80* and above 35* AND the aqustat on the 120 gal tank is calling for heat, instead of firing the boiler, this new WtW heat pump will heat the 120 gal DHW / buffer tank.
"From 80* down to 35* I plan to source this to the heatpump evaporator. The destination from the condenser is the 120 gallon DHW / buffer tank."
"I want to keep the 120 gallon DHW / buffer tank in the 120-145* range."
I only want to build 1 WtW heat pump if at all possible, as I have already bought all the rest of this equipment.
BBP
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