USE - Refrigerant Choice

Refrigerant Choice
By Tom Warner; President, Utility Service Express
We do it right the first time... ™

As an HVAC Master I am increasingly being asked about refrigerants and how they impact the residential equipment selection process. Unfortunately there appears to be a groundswell of concern being generated by many companies doing business in our service area.

What has become disturbing are the blatant pronouncements that R22 (the dominate refrigerant in current use) will become unavailable within the next several years. The Environmental Protection Agency clearly states (December 20th, 2006) that this inference can't be substantiated, nor is it likely to occur.

Here are straight answers to frequent questions:

If I buy an air conditioner/heat pump that uses R22 now, will I be required to replace it in a few years?

Absolutely Not! Air conditioners/heat pumps using R22 can be manufactured until 2010, and the production of R22 is not scheduled to be phased out until 2020. Additionally under the Clean Air Act R22 may be recovered and reclaimed indefinitely, thus it will be available for the servicing all (existing and new) R22 units for their entire design life.

If I buy a new air conditioner/heat pump now, does it have to use R410A?

No. HVAC manufacturers can continue to produce R22 units until 2010.
Can I use R410A in my existing R22 air conditioner/heat pump?

No. The use of R410A in any unit not specifically designed for the refrigerant can damage the unit and/or cause it to malfunction. Plus, it would void the regulatory approval of the equipment.
If I purchase an air conditioner/heat pump that uses R410A will I have to replace my indoor unit?

Not necessarily if your indoor unit is relatively new, however a knowledgeable professional will need to inspect the system to see if it will meet the performance requirements for R410A. If the unit is older, it will most likely need replacing.

To make informed decisions on refrigerant selection one must carefully weight all relevant parameters involved, and only then can a rational, conscientious choice be made.

Please do not rely on any information source that has a vested interest in either refrigerant. Nor should you place credence in private sector sources that may have hidden agendas. At Utility Service Express we strive always to remain professionally objective and we do not profit from the sale of one refrigerant over the other.

So why is there a refrigerant choice?

Scientific research in the 1970's discovered that refrigerants in common use (chlorofluorocarbons or CFC's) were having an adverse effect on upper atmosphere Ozone layer.

To address this serious environmental concern an international treaty (the Montreal Protocol) was negotiated by major world producing countries of these agents. Under this agreement the world producers of CFC's pledged to phase out their use. At present, 191 nations have become party to the Montreal Protocol.

Correspondingly the United States Government passed the 1990 Clean Air Act which sets a schedule for ending production of chemical agents that destroy stratospheric ozone. Under this Act the EPA has implemented a Phase out program which mandate Ozone depleting agents (R22 being one of them) to be incrementally phased out of use.

The current replacement for R22 is R410A which was developed and patented by Honeywell, who also owns all distribution rights to the compound. R410A is marketed under several trade names such as, GENTRON AZ-20®, SUVA® 410A and PURON®.

There is much debate about the qualities of R22 verses R410A as to their use in residential comfort systems. Of merit is the fact that equipment designed for R22 can't use R410A as a "drop-in" replacement.

R22

R22 Advantages

R22 is a mature refrigerant technology, thus well understood by the majority of technicians.
No equipment upgrades required: New vacuum pumps, pressure gauges, hoses, leak detectors etc.
R22 uses mineral oil, which has a much lower affinity for moisture than the polyol-ester oil used with R410A. This makes it easier and more cost effective to service. R410A requires a deeper vacuum and filter driers.
R22 is a single component refrigerant. Accordingly no issues with physical property change caused by improper charging or leakage.
R22 operates at lower-pressures (approximately 60%) than R410A refrigerant. Therefore equipment is lighter, uses less copper, etc.
Caveat: Reliability is a matter of engineering design, thus properly designed R22 and R410A systems are equally reliable, albeit an R410A system uses more materials which increases cost.
Existing R22 systems can be modularly replaced (A.K.A. Outdoor Condensing unit only). Currently the vast majority of systems reaching the end of their design life are R22, although as the R410A user base grows this will obviously become less an advantage.

Please Note: We don't recommend replacing only the condenser because any savings from reusing the A-coil are more than offset by the loss of SEER capacity and the cost of a soon to follow A-coil replacement.

R22 Disadvantages

Ozone depletion potential of 0.05: this is a "show-stopper" and the reason why R22 is being phased out of the market. There are no workarounds; after 2010 there will be no R22 units manufactured in the United States.
Cost: R22 is now becoming increasingly expensive, significantly more than R410A.
R22 is not as efficient a refrigerant as R410A. Under equal conditions R410A will yield an approximate 10% performance advantage over R22. While it may be questionable whether this will offset the increased initial investment of R410A equipment, the advantage at the electrical generation end is enormous. Therefore R22 can be construed to have an additional environmental burden over its ODP (Ozone Depletion Potential) by causing an increase in greenhouse gases and other issues of power plant operation.

R410A Advantages

R410A is an environmentally friendly refrigerant. Unlike R22, it has an ozone depletion potential (ODP) of ZERO. That means if R410A leaks out of the system, it does not harm the earth's protective stratospheric ozone layer. This is because as an HFC, it contains no chlorine.
Cost: R410a is now less than R22.
R410A is a more efficient refrigerant than R22, about 10 percent more efficient. This means that in an otherwise identical system, the R410A system uses less electricity to do the same amount of cooling as an R22 system. Since it uses less electricity, less greenhouse gases are produced in the power plants, so it is not only easier on your finances to operate, it is more environmentally friendly at the power plant also.

R410A Disadvantages are the inverse of the R22 Advantages, albeit after 2010 this issue no longer exists since R22 units will no longer be in production.

In practice what we have found in the past to be a dominate factor in deciding refrigerant selection is the diameter of the existing refrigerant tubing. If the size of your existing line set is marginal for R22 then the allowable liquid line pressure drop and suction line capacity losses preclude its reuse with R410A units.

That said, it is our professional opinion that to assure maximum longevity, R410A systems should be installed with new refrigerant tubing.

Bottom Line: Historically if your current line set was buried behind sheet rock (wallboard) initial installation cost would have been greater than efficiency gained from R410A during the operational life of the system. However this is changing... with the price of R22 rising rapidly even in such situations R22 may still not be a more cost effective option. Thus in nearly all cases R410a will be the refrigerant we now overwhelmingly prefer to use.