Nothing has been run to the hot water furnace in the basement. (phase 2) I still need to clean things up and do some temp testing on the pex runs but I’m very satisfied with what I have so far.
All the pex is run and insulated to my cast iron rad in the living room and I got the rad up to about 155°F the other day. 19°F outdoor temps and a 2100 watt load on the engine, 145’ round trip on the pex. If I want it will be easy to add more insulation to most of the pex. The pex runs through my garage attic to the house attic, then down to a closet where the valves are and out the wall into the living room rad.
It I remember correctly the cost of the pex and insulation was around $2.10 per foot, acquired from different ebay vendors. About $125.00 for the fittings, ebay as well
There’s about 16 gallons of coolant in the secondary loop. It took 60 minutes for it to reach 95°F where it enters the living room rad. In 2 hours it was 140°F. At that point I was losing about 2°F on the inbound, 75’ run and the rad shed another 6°F. Accurate readings were difficult. All test points were flat black but the smooth surfaces seem to read about 5° colder than the rough ones and my test points were a combination of both. The pump is a Grundfos 25-58U, another ebay item. It didn’t come with specs and I can’t find any on the internet. I made sure it worked with a garden hose when I got it and it moved a lot of water on high with no head. It’s a 3-speed unit and I had it on medium all day.
I know my delta is really low at ~150°F but it will get better with additional loads. However, the engine room stayed at a nice 80°F, the coolant returning to the engine was 140°F and I had a nice toasty antique radiator keeping the house warm. The wood stove was on but as low as possible. I’ll need it tonight, Their saying 3° lows.
I'm quite certain I’ll be able to heat the domestic hot water to more than acceptable temps. I won’t be able to take 3 showers in a row but it should be more than I need.
Thanks, Geno
Engine coolant heat-exEngine coolant heat-ex 1Exhaust heat-exPump and accessory hookup. Grundfos UPS 25-58ULiving room radPex and insulationBad plumbing diagram. Gen shed and garageBad plumbing diagram2. House, first floor and basement