home A/C and R-22 - cost per lb

Comon Chris the word is few other it's cool man, do you digit man you need to to NYC bronx section.

stry, if you you're lucky, you can work with your A/C tech and he'll sell i t to you wholesale if there's labor work involved in the sale. It's still g oing to run you $80/lb and even a small system is gonna set you back $500. Hope this is a helpful message and I don't know who is regulating the costs of R22, but it's more than DOUBLED in the past year or so.

Richmond virginia-5/1/2013. $78 dollar service call and $90 per lb R22.

You could not be more wrong

Yes some of replacement Refrigerants use some mixture of propane/beuteen etc whatever, the Refrigerants are approved by OSH that is all one needs to know! And yes are whole lot more efficient then old 22,12,and 502, and specially over 134 and 410, 410 is efficient on high pressure but very lousy on low pressure/temperatures....

Oh really?

=============== Journal of Environmental Science and Engineering Dec 2010, Volume 4, No.12

A Comparative Study on the Performance and Environmental Characteristics of Alternatives to R22 in Residential Air Conditioners for Tunisian Market

Abstract: This paper presents the simulation results of a 9000 BTU/h air conditioner with some selected fluids that have been assessed for their suitability as alternatives to R22 for air conditioners. Only those refigerants with zero Ozone Depletion Potential (ODP) are considered.

Ther performance of 11 refigerants were comparatively studied using the simulation software NIST Cycle_D. R134a, R290, R600, R404A, R407B, R407C, 407D, R410A, R410B, and R417A are considered in this study.

The thermal performance obtained with R134A and R290 (propane) are very close to those of R22. The power consumption of the units operating with R404A, R407C, and R410A are higher in the range of 22-31% with respect to R22. For units operating with 407A, R407B, R407D, R407E, and R410B, the electric consumption is higher in the range 10-23%. For R600, the power consumption was in the range 6-8%.

For all the fluids, the COP (Coefficient of Performance) is lower by

I was wrong about R22 having better efficiency than R134a (it has the same efficiency / COP) but R410 (A or B) is a big loser in terms of electrical efficiency and COP compared to R22. R410a is what you will get when you install a new A/C system these days.

But clearly, propane (R290) is the way of the future for residential air conditioning, as a drop-in replacement for R22 and R12.

Again, R22 is (was) one of the most efficient working fluids - equivalent to R134. Not sure how it compares to R12. R12 probably has a higher COP than R22, but it's a major ozone killer compared to R22.

See also:

=============

Conclusion: Hydrocarbon refrigerants have environmental advantages and are safe in small quantities. R290 (propane) can replace R22 and HC mixtures can replace R12 and R134a in applications using positive-displacement compressors.

HC refrigerants are completely soluble in and compatible with hydrocarbon lubricants. HC liquid absorbs only trace amounts of water, like R12, so HC refrigerants are completely compatible with R12 driers. HC refigerants with appropriate vapor pressures are drop-in replacements for CFCs on equipment using thermostatic expansion valves. ==============

Exactly!

My 22-year-old central air unit used to draw about 16 amps and my new

Did you really run the numbers? You have to have *very* high electricity rates for the really high SEER units to pay for themselves. BTW, current draw doesn't tell the whole story (either in "efficiency" or energy used). By itself, it's a meaningless number.

You do realize that your source is a study of using R134A and R410 in OLD R22 based systems, don't you? It's being used in systems that were never designed for it. It says nothing at all about the efficiency when used in new systems that are designed for R410. If the efficiency is so lousy, how is it that we had 10 SEER R22 systems that are being replaced by new 14 to 18 SEER R410 systems?

You also need high usage of the AC to make them come out ahead. When I replaced mine 2 years ago, I took a look at the options. The cost went up a lot when going from 14 SEER to 18. My electric cost is 18c kwh and I concluded that with my usage it would take a long time to recover the extra cost. And you'd have to be confident that the unit will last long enough too. I went with the 14 SEER. Part of the cost differential may have been due to the fact that it was a 5 ton, there are less high efficiency units in that size.

Also agree that the current draw by itself doesn't mean much. Biggest potential there for a difference would be if the two systems were not of the same capacity. You could replace a

Assuming 40 degrees evaporating temperature and 105 degrees condensing temperature.

R410A gauge pressures will be 344 head and 119 suction R22 gauge pressures will be 211 head and 68 suction

R410A compression ratio calculation:

R22 compression ratio calculation:

Practically a tie. So in terms of compressor work-load, it's pretty equal. The higher pressures in the R410a system require a thicker compressor shell, and the long-term durability / cost-of-ownership of the entire system has yet to prove itself. The lubricating oil used in R410a absorbs more water than the mineral oil used in R22, so that's another factor.

R410a will also be phased out (or phased down) so who knows if owners who have switched from R22 to R410 will again face the cost of switching in 10 years (to R600?).

The compressor is one of two components responsible for maintaining a pressure difference in the refrigeration circuit. The other component is the metering device at the inlet to the evaporator. For residential air conditioning, a target indoor evaporating temperature is around 40 degrees F. What OEMs have been doing for some time now when playing the SEER game is to lower the condensing temperature, which would concurrently lower the head/discharge pressure. With evaporating temperatures/pressures fairly constant, a lower condensing pressure lowers the compression ratio of the compressor, which in turns reduces energy required to run the pump.

Until R410 came along, OEMs kept making larger and larger condensing units for the same nominal tonnage ratings to reduce head pressure for R22 systems. Not only was that the goal, but the larger coils made for better subcooling of the condensed liquid so there would be a corresponding gain in net refrigeration effect in the evaporator (how much actual refrigeration occurs after the refrigerant is cooled immediately downstream of the metering device).

One thing to consider is the difference between ECM and PSC motors and their effect on SEER ratings, which have nothing to do with what the working fluid in the AC system is.

I could replace the HVAC blower and condenser fans on an R22 system with ECM motors and raise the SEER of the system.

Are any compressor motors ECM these days?

Does all of the above mean that you agree that the R410 systems that are being sold are in fact as efficient or substantially more efficient than the R22 systems they replace and that using R410 is not a significant issue from an efficiency standpoint?

All things being equal, the difference between SEER 18 and SEER 14 is just that; 22% (that's really the bottom line). From everything I've seen, 14 is about the optimum price point. As you point out, the up-front cost skyrockets above that.

Right. In addition, a lower efficiency unit may have a lower PF, increasing the current further for the same KW used. It likely wouldn't be 40% but it could easily be noticeable. Current is a lousy thing to measure where watts is what is important.

I just replaced my 29-year-old central A/C. Efficiency of the new unit is more than twice that of the old one.

That may be true, though you may have saved even more money by not replacing it or replacing it with a lower efficiency unit. Like may such decisions, neither the up-front or the recurring costs tell the entire picture alone.

I ca not comment on whole but perhaps the answer to you question if current

Does all of the above mean that you agree that the R410 systems that are being sold are in fact as efficient or substantially more efficient than the R22 systems they replace and that using R410 is not a significant issue from an efficiency standpoint?

What answers exactly are "industries" giving that are false? Pretty much what I've heard is that the R410 systems are safe for the environment because of the R410 and that the systems are a lot more energy efficient than the typical older systems they replace.

Sure, that's part of it. They've also changed and improved other major components too. Larger evaporators, ie N coil instead of A, scroll compressors, etc.

What do you think the cost differential is between what R410 costs and what R22 used to cost prior to the phase out? Allowing for inflation over the last decade, I don't see it as being a huge difference. R410 is probably a little more expensive. But in the overall cost of a repair bill when you need to add enough to matter, it shouldn't make a big difference. Not sure what the issue is that you're referring to with ease of service.

All the parts of a 410 system must be built to handle the higher working pressures. That makes it more expensive. Leaks that happen because of higher working pressure will reduce system efficiency over time.

Comparing the heat exchanger size and design of 410 vs 22 is disengenuous - you could have just as easily (and more cheaply) built more capable heat-exchangers for r22 systems.

I'd like to see a comparison (real dollars spent by real home owners, real dollars saved over time, etc) if someone takes a 15 to 25 year-old R22 system that needs a recharge and instead of replacing it with a new r410 system, charge it with R290 (propane).

R410 effect on ozone is nil (that is true) but as a greenhouse gas, it's not that good. R410 will be phased down in 10 or 15 years, probably will be replaced with r600.

Again, from a carnot-cycle point of view, and from real-world working pressures and compression ratio analysis, there is no difference between the two systems. If you replace a small A-frame r22 with a larger N-frame R410, you can't say that your increase in system efficiency has anything to do with the r410 circulating in the lines.

And again I ask -> does the use of ECM motors (plenum fan, condenser fan) get factored into SEER ratings?

I don't see that in the installed cost of a new system. The systems today are about the same cost as the ones that they replace, adjusted for inflation. That is if you take an entry level system from 20 years ago, which was 10 SEER and compare it to a 14 SEER system today. Factor in utility rebates, govt rebates, and lower operating costs and they are less expensive than the old ones they replaced.

Nonsense. If a pipe or component is going to fail, it's typically from corrosion, a bad braze joint, etc. And I'd say the probability of that isn't dependent on the system pressure. And if you get a leak, it's not really an efficiency issue, because before very long with a typical leak, it's not going to run anymore.

But who cares? It's that the new R410 systems are a lot more efficient that's the bottom line. Exactly how they got there doesn't matter to the consumer.

You could try it and tell us. If it works you could have a new business. Of course the problem is that a 20 year old system that needs recharging, probably has a serious problem that caused it to need recharging.

Who cares? It's not like a car or power plant that's BURNING fuels that release CO2. Any release of R410 is going to be so small, it's irrelevant, except maybe to an environmental nut.

I never claimed that it did. Nor do I recall seeing manufacturers make that claim. What I see them usually saying is that R410 is environmentally friendly, R22 is phased out, and that the new systems using R22 are a lot more efficient than the old systems.

I guess you could address that to the folks that do the ratings. AFAIK, the only ECM motors used would be for the blower motor in the furnace, if it has one.

Wholesale is about $500 per 30lb Cylinder now. It continues to grow every 3 months or so.