Posted on 08/30/2011 7:12:18 AM PDT by Red Badger
Of the volcanoes, only Erebus remains active. At 3794 meters, Mount Erebus is the highest point on Ross Island and the largest, most active volcano on the Antarctic continent. I thought the ozone hole was caused by Mount Erebus - Antarctic Volcano
Older houses generally were ducted for straight heat application, and required less air flow. (To a point, you just got warmer air out of the ducts....if it was too restrictive, the furnace would malfunction).
With the advent of central cooling and heat pumps, those duct systems had to be improved. Modern duct systems use perimeter supply ducts and a centrally located return. Many of the older system used exactly the opposite...multiple small returns on the outside walls and the supply registers on the interior.
Sounds like what happened in your house!
Honeywell has a vested interest in R410a also. Here is a quick link to a system tested in high ambient temps with R22 vs. R410a,
http://www.fire.nist.gov/bfrlpubs/build02/PDF/b02186.pdf
The R410a was noticeably less efficient. Under perfect lab temps, Honeywell might be able to show the result quoted, but in real life, it is a poor substitute for R22.
Sorry smoking, I didn’t see your response to dila...thats what I get for just checking pings and not the thread.
You’re spot on.
I always figured the 410a would be less efficient, just based on the fact that the pressures are higher, which would require the compressor to work harder, but I don’t really understand all the technical details. Unless one type of refrigerant is supposed to magically absorb more heat from the air than some other type? It seems like they are fairly equal up to 95 degrees or so, which is what all air conditioning units are rated for.
I’m not an engineer, so I can’t enlighten you much on the details....it is complicated.
The physical attributes of the refrigerant play a very important role i.e. specific gravity, boiling point, etc.
In fact, R410a is a zeotropic blend of refrigerants to give an acceptable performance, whereas R22 is a compound.
I base my claim of the lower efficiency based on discussions with engineers at a couple of the large HVAC mfgs other than Carrier when the R410a units were in design.
You’re right. You shouldn’t need new duct. But you will need a new evaporator coil or a txv valve added to the existing coil. Gets expensive.
Oh?
No.
With less temperature differential, they'd work LESS hard!
The difference between R-22 to R-410 is the pressure. R-22 ran at a lower pressure so your line set (pipes to your air handling unit) did not have to be that tight. With R-410 it is more important to have good connections so no leaks.
You duct work excluding the coil does not have to be changed but if it is old you should make sure it is tight. If not you are cooling off your attic and crawl spaces.
I always suspected the gas change was a scam.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.