New central air unit
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Topic: New central air unit
Posted By: HD6GTOM
Subject: New central air unit
Date Posted: 03 Aug 2021 at 9:47pm
| The boys got it put in today. Train unit. It has something like 400 freon in it. New stuff is like 400 psi in the lines. Its quiet and cold as heck in here tonight. We were gone or outside today, the boys left it set on 86°. I turned it down to 75° and the temp came down in a few minutes. The old unit would have taken an hour or more to cool it down. Grandsons been living in the basement, he says he's gonna have to dig out his winter coat and a couple of quilts for his bed. It is freezing cold down there. I shut off all but 1 of the registers, hope it helps. |
Replies:
Posted By: steve(ill)
Date Posted: 03 Aug 2021 at 9:54pm
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R410a is what they normally use now... YEP.. higher pressure and more efficient. ------------- Like them all, but love the "B"s. |
Posted By: DSeries4
Date Posted: 03 Aug 2021 at 10:24pm
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Try to keep as many registers open as possible. With only one register open you will be severely restricting airflow through the coil and could result in it freezing up. Best to find a temperature that is between 75 and 86 where both you and the boys will be comfortable. ------------- '49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080 |
Posted By: Dave H
Date Posted: 04 Aug 2021 at 8:35am
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Listen to DSeries4. ya gotta let the air flow or you are gonna lam something up. Why not use the thermostat for temp control?
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Posted By: steve(ill)
Date Posted: 04 Aug 2021 at 11:34am
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I hope he is shutting down the registers in the BASEMENT and putting 90% of the air upstairs thru open vents.. COLD air is heavy and will flow down the steps to the basement.. Normally dont need as many vents downstairs. ------------- Like them all, but love the "B"s. |
Posted By: DaveKamp
Date Posted: 04 Aug 2021 at 10:38pm
What D said! If you close off registers, the blower will not be able to move enough warm air over the A coil to prevent it from freezing up. This is a common issue for an 'oversized' AC system... once the A coil freezes, the refrigerant will not have significant heat to absorb, thus it won't expand to gaseous state fully. The result can be liquid refrigerant flowing back to the compressor/condenser, causing a hydraulic-lock risk to the compressor. R410A is what the two systems I installed in my house use. Since my old house had no provision for 2nd story cold air returns, I installed one system in the attic, and one in the basement. This makes for excellent domestic tranquility, in that the upper floors' temperatures are always held within HER COMFORT range, while the lower floors are TOO... (normally, the upstairs would be hotter simply because all the hot-air would rise to upper floor by convection). Yes, 410A requires higher pressure. My units run a TXV (thermally variable orfice) which sure makes the unit easier to cool well. The lineset MUST be silver-soldered together, then drawn down HARD with a stout vacuum pump. I got mine to pull down to 11 microns, and the overnight lockoff test showed it'd crept up to just 17 microns by same time next day... probably just heat in the pipe... but the key, aside from having good seal on all joints, is to draw it down several times, in stages, to drag out every bit of atmostpheric moisture that you can. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
DSeries4 wrote: