hvac'in

Sunday, I ran the copper refrigerant lines in the crawlspace from the blowers to the outdoor unit. They are temporarily supported in place with a few hangers and some velcro straps. Once insulated, they will be permanently supported.

Monday, I spent Valentine's Day with my love.

Tuesday morning, I determined the motion sensor on the side of the house was bad. I spent almost an hour looking at lines and reading voltages and what not. I am slow. The rest of the day was spent helping install my parents' new dishwasher.

Wednesday, I replaced the motion sensor with a new one. I then made flares for the indoor refrigerant connections. It was too windy/dusty outside to work on the exterior flares.

Thursday, I connected the outside flares, pulled a vacuum on one set of blower lines, and cracked the service valve briefly for some soap & bubble checking with low pressures. No bubbles were spotted. This was an exciting day, as I learned the difference between standard hose fittings and low-loss/anti-blowback hose fittings. The latter are very, very handy.

Friday, I vacuumed the other blower lineset, also performed low pressure bubble checks and then fully opened both service valves. This was another fun day of driving back and forth from Milford to Dover, as I discovered the very limited space around the service valves on the Fujitsu required just the right combination of tiny fittings to adapt from a 5/16" to 1/4", and to bend 90 degrees from the unit housing for clearance. The wiring was completed, and the system connected. The instructions stated to wait 12 hours after power before testing.

Saturday morning, I tested the system heat. It was about mid-forties outside. The outside unit was very quiet. It very slowly ramped up its speed. The indoor blowers were also incredibly quiet.. Even full blast, the fans make little noise. They put out nice heat, too.

After an hour or less, I shut down the system to allow the lines to cool, so I could insulate them. As I was fumbling with some pipe insulation outside, I noticed a small bubble slowly form and pop at one of the low pressure flare nuts. I stooped down for a closer look, and watched another bubble slowly form and pop. Doh.

After some investigation of my documentation I determined it was possible I could perform a "pump down" or "recapture" to suck the refrigerant back out from the linesets into the outdoor unit. Then, I would be free to disassemble the flare and try again. If I haven't lost too much refrigerant - which I don't think I have - then it should still work fine without dealing with a recover/recycle operation. I don't have equipment for that, and would likely run a few hundred dollars to have a contractor perform for me. I don't even know if a supply house would sell me the R410A if I had a recovery unit, without a CFC card..

I realize now a nitrogen pressure test is critical to ensure a tight system before bringing the refrigerant into play. A $100 regulator isn't much of an investment, and I found a local supply house with nitrogen tanks.

So, I ordered online a nitrogen regular for $60, a leak detector for $40.. it should arrive sometime the middle of this week, and then I can check for leaks before I release the refrigerant again.

Once that's all done, I can check pressures and temperatures and compare to the spec sheets to ensure the charge is within acceptable range. The unit comes charged with enough refrigerant for a total line distance of 100ft. My units are roughly 40ft total, 60ft less than the max. The specs list a charge of about a quarter oz/ft, so with 60 x 0.25 = 15oz lost, it should still perform to spec. The total factory charge was 74oz, so that's about 20% lost. This is a guestimation of course, only testing will tell for sure.

In the mean time, I'll remake that one flare I know for sure is bad, when the weather looks good. I can run the pipe insulation as well. And finish the condensate piping. And the drain/waste/vent piping..