[buffalobillpatrick]

Hello, first post on this site.
I have been reading & learning here for weeks.

I really like this place & want to thank you all for sharing so much info!!!

What I'm doing is trying to design a 2.5 Ton WTW system, using new parts from ebay, Surplus City, etc.

My new house is not built yet & I am designing it to be very energy efficient.
The heat loss calculations look to be about 30K btu / hr at design temperature of 2* F.

Thanks to AC-hacker's thread I am building my coroplast HRV unit.

The building site is in Teller County Colorado about 10 miles W. of Pikes Peak. Great solar location at 8,800' altitude.

The excavation for the house shows that there is only about 2" of top soil, from there down it is decomposed granite, small chunky gravel, much Radon.

So it does not look very good for slinky loops heat exchange. Probably I will put some pipe around the basement perimiter & bed it with crusher-fines to improve heat transfer?

I have bought 240 ft2 of used hot water solar panels + a 1000 gallon fiberglass tank. I will ground mount the panel rack vertically & bury the tank (very well insulated) outside basement close to the mechanical room wall.

I have bought enough of the O2 barrier pex for the radiant floors with pipes spaced 8" OC. + all the needed pumps, HX, valves, etc.

I was my own General Contractor on the house I live in now. I have designed & installed 2 radiant floor systems, learning on each.

As I'm fed-up with mod-con boilers at high altitude, I have bought an 88% Eff. NG Burnham RV-3 cast Iron boiler, about 33K btu output at this high altitude.

It will have long burn times heating the 120 gallon DHW / buffer tank. Heat will be extracted from this tank to heat the floors via the same HX that heats it from the boiler. I have this 2-way HX setup in my current house & it works great!

The solar storage tank will be used to preheat the 120 gallon DHW / buffer tank and the radiant floor directly when it's > 80* F.

In periods of bad weather I will draw the temperature of the solar tank down below 80* F , at which point it becomes usless for heating the floor directly.

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 have got some Arduino HRV sketches working & will use it to read sensors & control the system. I copied some code from the manifesto thread. Thanks

At this point I have bought a 4.7 ton refrigerant/water GEA flat plate HX, 30 bar, off ebay for use as the condenser.

I think I like this compressor from Surplus City:

Copeland 2-1/4 TON SCROLL COMPRESSOR, VOLT:265, HERTZ:60, PHASE:1, REFRIGERANT:R-22, LRA:58, CONNECTION SIZE:1/2" x 3/4" SWEAT, CAPACITOR:40 x 440, HEIGHT:15", BASE DIMS:7-1/2" x 7-1/2", WEIGHT:58 LBS 2 OZ

I think I will use propane or Mapp for refrigerant. This unit will be built this year & installed after the Certificate of Occupancy is issued, as I don't want a hassle with the building inspectors over a DIY unit.

I need to figure out all the rest, TXV / EEV, evaporator, IHE, superheat, subcool, etc. etc. etc.

Again thank you all.

BBP