OK,
That big house with the missing HVAC is looking more and more real. We are now
In Contract. As mentioned before, the two condensers were removed, as well as the furnace in the garage. However, we went out there with my termite guy the other day, and discovered that the upstairs furnace is untouched!
I don't plan to spend any big bux on this till it's ours, but I did indulge yesterday in an EPA608 test at the local HVAC store. I know it really doesn't mean a thing, but it was fun
. I think I even passed the TYPEIII part - woo those centrifugal coolers are weird.
Am planning to go all R22, so i can use the existing upstairs furnace, AND not mess with multiple gases.
Now I need to get some of that SIL-FOS rod, so I can practice brazing. Can I practice with ordinary plumbing copper pipe, eor does it need to be the special HVAC stuff? I do have an Oxy-Acetylene setup, and am fairly good at gas welding. I also do TIG welding, a smidgeon of MIG welding ( not as good at that as TIG ). Have also soldered plumbing pipe AND done probably hundreds of thousands of electronics solder joints ( used to be an electronics tech ). I wonder if this would be a good excuse
to get one of those nifty little Meco torches?
I will probably rent a nitrogen cylinder at the welding store. Might have to buy a regulator. OTOH, it's possible that my Argon regulator will work, although the low pressure gauge is calibrated in CFM instead of PSI. Would probably plumb a
separate gauge to it to verify the pressure.
The missing condensers are Payne PA13NR030-H. Web research leads me to believe that Payne is not a good brand, especially the newer ones. I'm leaning towards Goodman. Comments?
Issues to resolve include:
* Sizing the downstairs unit. I can punt and just make it the same size as the old one, but it's possible that the builder oversized them. Once I own it, I can go take
all the measurements and do a block load calculation. Another punt could be a
two-stage variable speed furnace. It could mostly coast at low heat, with the second stage available as insurance. Also I need to figure out whether to buy an 80% efficiency furnace, or 90-95%. What are the tradeoffs ( besides $$$ )? Are the higher-efficiency ones bigger? Less reliable? Noisier?
* On the condenser that will work with the existing upstairs unit, I need to match
the tonnage ( 2.5 ), the size of the refrigerant lines ( I think it's 3/4" for the vapor line, and 3/8" for the liquid line ). Also, the indoor coil has a TXV so the condenser should
have the hard start kit. AND I need to know the exact model of the evaporator coil so I can figure out the proper refrigerant charge.
As a gadget freak, I am planning to get a couple of networked thermostats. The RTCA ones look good. I would also like to monitor the CO2 for a while to see if I need any sort of fresh air system. There's a guy on Ebay who has CO2 sensors for $50. One of these sensors can connect to a low-voltage RS232-USB adaptor ( also available on Ebay, but I already have 2 ). The USB adaptor can hook up to some little computer. In my case, running Linux and hooked to the home network.
- JerryK
Linear Mode
