Okay – I read fine homebuilding because my husband subscribes, so I know next to nothing…… and I am the one tasked with finding a HVAC company to replace out existing unit – go figure. I submitted a post a while back asking for advice and got great comments. Now, one more question….
I thought that the “next big thing” was the advent of Puron because the were phasing out Freon. Freon is supposed to be getting more expensive, Puron will decrease in price, etc…. The contractor we decided on tells me today he wouldn’t put a puron unit in his own house. He indicated Freon was to be phased out in another 20 years, and the pressure with Freon was about 250 versus 500 with Puron. This is all contradicts what I heard all the other contractors we interviewed say.
Not only was it bad enough choosing a contractor, since none of them are apples to apples, but now my head is spinning with differing opinions on the things that are similar!
HELP!
Replies
do some web searches
puron is carriers name for a specific type of freon
higher operation pressures on the new stuff (puron)
some are comcerned that will cause coils to fail quicker.
also handling precautions must be taken.
the puron units I have heard are quiet
look at carriers site and trane's for two different views.
"Chemically, Puron refrigerant is an environmentally sound, 50/50 blend of R-32 and R-125."
Apparently intended to replace r-22. r-22 remains quite cheap at this time, however.
The term "Freon" is a Dupont trademark, and generally means r-12, which is expensive now.
Edited 7/19/2004 4:15 pm ET by csnow
r-12, which is expensive now.
Expesive enough that it's a common item to smuggle in from Mexico (where it is still quite legal).Occupational hazard of my occupation not being around (sorry Bubba)
legal in canada and carribbean I think also
Ann,
Puron is a trade name for a recently developed refrigerant that is designated by the ASHRAE # of R-410A. It also goes by the trade names of Genetron AZ-20, Forane 410A and Suva 410A. It is manufactured by Honeywell, Atofina and DuPont.
It is used in systems that differ slightly from their predecessors that utilize the more standard R-22, which is what most people mean by "freon". By 2006, all residential split systems (what the industry calls your central air conditioning) are required by federal law to be at least 13 SEER and all (or most) of the present systems that currently meet that criteria, use the new refrigereant, R-410A.
R-22 is begining to be phased out now. It will not be available after 2020, or thereabouts. The systems that use R-410A do operate at higher pressures than those that operate with R-22, but they are typically much more efficient. The higher pressures are not a concern for a properly trained technician, not more so than any other. The operating pressure of the high side of you AC system, is a non-factor in making your selection.
R-410A is much more environmentally friendly than R-22, it is the future of small split systems. If I were real cheap, I would by a 10 SEER system that uses R-22. If I were more interested in the future I would by a 13 SEER unit that uses R-410A.
"but they are typically much more efficient." - huh, please provide reference and data....
Bland inaccurate misleading statements just muddy the water.. The unit , when it is more efficient, is not because of the 410A itself, it is because the exchangers are much bigger (*more area) in the first place. In order of fluid performance with the same size condensor and evaporator, NH3 is still best, propane next, then the freons CFC, HCFCs, and the new stuff is last which is why it hasn't been used large scale to date. NH3 and propane obviously can't be used residentially due to the safety concerns.
In answer the original question, I'd stay with R22, it is only about $1.30 a pound nowadays (went up 50cents last year however, next cusp isn't till 2010?? or so.
Anytime you are pumping a compressor of any type to 500 psi vs 200 psi, there is a lot of extra wear (or initial expense) on the compressor and the lifetime is shorter. By 2020, you can get a recharge (if needed) and be good till 2030, by which time 410 will likely be obsolete. Also stress fatigue on the coils and piping, etc. etc..
> NH3 is still best, propane next, then the freons ....
Weren't there also some sulphur compounds? I remember a central refrigeration system in a 1920's building that was H2S or SO2 or something like that. It was a bad smell, but I don't remember which bad smell it was. ;-)
-- J.S.
Right you are John, lots of condensible liquids used, SO2 common then. For a complete pre CFC chemistry, I pulled pop's old 1930 edition of Mark's handbook. Man, wouldn't the EPA go bonkers over some of this stuff in a residential ac?
CO2 would be nice and safe but look at the pressures on that, makes Puron look good even. Remember, to be usable for a heat pump/ac, the stuff has to be able to boil below the coldest temperature and have relatively low vapor pressure
material some pressures boiling point at 14.7 psi
water 1.7 psi @ 120F 212F
Mercury vapor 100 psi @ 900F 670F or so
Diphyenyl 37 psi @ 8F 492 F
NH3 286 psi @ 120F -23F high enthalpy but poison
SO2 121 psi @ 120F 12F
CO2 1072 psi @ 88F brrrrr!below -50F
Ethyl or Methyl chloride 41 psi@ 110F 55F
Propane 240 psi@120F -45F unfortunately, flamable
Butane 71 psi @120F 30F
isobutane 98psi@120F 10F
di and trichloetylene 800 psi@400F 122F
R22 80 psi @ 50F -41F R22 # from memory,may be off
Thanks for all your replies. It helps somewhat - for my non-technical self!
:-) Happy Friday!
"please provide reference and data...." Do you know of anyone that sells a 10 SEER with R410A? Do you know anyone that sells a 15 SEER in R-22?
The available products on the market currently is proof enough. I made no claim or assertion that the R410A refrigerant makes for more efficient systems, only that manufacturers have almost (if not) exclusively, chosen to utilize R410A in their higher efficiency equipment.
Edited 8/4/2004 8:55 am ET by Timbo
I have no technical background.
Recently retrofitted central A/C in our 1950's brick ranch, using a very reputable Carrier installer in our area.
When I asked about Puron, he steered me away from it.
His recommendation was to stick with the conventional stuff.
He installed a properly sized and configured system that runs quiet and does an excellent job, so my suggestion would be to weed out the bubbas and make sure you find the most reputable installer irregardless of the brand.
I was intersted in Lennox, but felt more comfortable talking to and dealing with the Carrier person.
It just depends on where you live, I suppose.
The contractor we decided on tells me today he wouldn't put a puron unit in his own house. He indicated Freon was to be phased out in another 20 years, and the pressure with Freon was about 250 versus 500 with Puron
Agree 100% with the above, I wouldn't put a Puron unit in my own house either -- sounds like you selected a good honest contractor.
There are a lot of hvac hacks out there (go look at the 'wall of shame' on hvac-talk.com and comments about bad installations) that just want to sell whatever the biggest markup is. I built heat pumps from components in the 70's and 80's so had all the grandfather equipment when EPA came along, one of the best secret kept secrets ofthe hvac salespeople is that brand, etc doesn't make a hill of beans difference in cost of operation if the unit has the same size coils, piping, and copeland scroll compressor (IMHO, don't buy any unit that does not have copeland scroll compressor) Also, see if your hvac guy will agree to replacing the "probable' orifice flow controls on you new unit with txv's (an extra hundred bucks or so) as overall cost of operation will be lower over time.
One last hint that many hvac people overlook - occasionally a unit from the factory will have 2 of the pipes in the outdoor unit touching where they cross (e.g routing to get to the other side of the box, no connection) , this will lead to wear and a leak in a few years due to vibration - check for pipe separation and secure close crossing points of different pipes with RTV.