Summer weather in the Midwest is normally hot and humid, and homeowners rely on a dependable and efficient central air conditioning system to keep the indoor environment comfortable and healthy. Fundamentally, AC equipment provides conditioned air by transferring heat energy from the living area to the outdoors. Refrigerant is the medium used to accommodate the thermal transfer since it has unique evaporation and absorption properties.
For many years, hydrochlorofluorocarbon (HCFC) was the refrigerant of choice in residential air conditioners because of its exceptional efficiency, low production cost and ease of use. However, environmental concerns eventually led to the adoption of measures that mandated a gradual Freon phase-out, which will rapidly accelerate in 2015.
Understanding the Refrigeration Cycle
To appreciate the important role refrigerant plays in providing cool conditioned air, it is important to understand the basic concepts of the refrigeration cycle.
The action of the compressor converts low-pressure gas into high-pressure gas. The condensing fan dissipates the accumulated heat into the outdoor environment. The refrigerant emerges as a high-pressure liquid and is transformed into a low-pressure liquid by a metering device as the evaporator coil. The furnace blower draws warm indoor air across the coil, and heat energy is transferred to the refrigerant. The cooler air is pushed through the duct system into the living area, and the refrigerant returns to the compressor where the cycle begins again.
Traditional AC refrigerant is an effective medium because of its low boiling point and ability rapidly change its physical state without compromising efficiency.
History of Air Conditioning Refrigerants
In general, refrigerants are based on an idea originally introduced by Benjamin Franklin and John Hadley in 1758. They created a formula that used the quick evaporation characteristics of ether and alcohol to cool objects down to sub-freezing temperatures.
The concept was expanded by Michael Faraday in the early 1800s when he created an early version of the refrigeration cycle, which included compressing and evaporating ammonia liquid. Some twenty years later, this same technology was used to air condition hospitals and other large institutions by blowing air across blocks of ice.
Willis Carrier is generally credited with inventing the first commercially viable air conditioner. While the basic principle Carrier devised is still in use today, his system used methyl chloride, propane and ammonia refrigerants, which were all toxic or combustible when they leaked.
The Freon trademark represents a group of products developed in 1928 by a team of DuPont scientists headed by Thomas Midgley Jr. This included chlorofluorocarbon (CFC) and HCFC, which were the first non-toxic and non-combustible refrigerants developed for commercial use. Dupont used a numbering system to identify the various blends they targeted for different industries. Residential and light commercial AC equipment built before 2010 used R-22 refrigerant, which was extremely popular and widely available.
Montreal and Kyoto Protocols
In the 1970s, a clear link was established between CFCs and the destruction of the earth's ozone layer. It was determined that continued ozone depletion would result in a substantial increase in the intensity of ultraviolet radiation penetrating the atmosphere. The data was compelling, and the U.S. became a signatory to the 1987 Montreal Protocol, which is an international agreement that established the timeline for the worldwide Freon phase-out.
The Montreal Protocol was later amended to provide a specific schedule for the eventual elimination of CFCs and HCFCs. The tenants of the Protocol were later enforced in the U.S. through Title VI of the Clean Air Act adopted in 1990.
The timetable for the elimination of R-22 production and usage is outlined as follows:
- January 1, 2004: The U.S. is required by the agreement to reduce its total HCFC consumption by 35 percent below its baseline cap.
- January 1, 2010: The U.S is required by the agreement to reduce its total HCFC consumption by 75 percent below its baseline cap. Allowance holders can only import or produce R-22 replacement products to service existing equipment. Fresh R-22 was not to be used in new equipment manufactured after this date, which essentially mandated that the HVAC industry convert to R-410A products.
- January 1, 2015: The U.S. is required by the agreement to reduce its total HCFC consumption by 90 percent below its baseline cap.
- January 1, 2020: The U.S. is required by the agreement to reduce its total HCFC consumption by 99.5 percent below its baseline cap. As a result, HCFC manufacturing will be effectively eliminated, and only recovered, reclaimed and recycled R-22 will be commercially viable.
R-22 Replacement Issues and Options
The dramatic reduction in the R-22 consumption cap is beginning to affect product pricing as contractors anticipate limited supplies relative to demand in 2015. In fact, the price of R-22 has already increased by 500 percent since 2003. In some areas, prices have quadrupled in just the last six months. Current quotes for AC refrigerant range from $75-$150 per pound, depending on the contractor and the area.
For existing R-22 equipment owners, ignoring a refrigerant leak will no longer make sense from a financial standpoint. A continued reduction in supply will also encourage homeowners to purchase a maintenance agreement from a qualified contractor, like those found on comfort24-7.com. Routine maintenance will optimize system performance and identify small problems before they escalate in catastrophic failures.
As part of the Freon phase-out program, technicians who service R-22 based systems are now required to have EPA Section 608 certification. Techs who provide R-22 replacement service must carry agency issued credentials to verify they are trained to safely handle the material.
As R-22 becomes increasingly scarce, contractors will look to reprocess used refrigerant through one of the following methods:
- Recovery: The recovery process involves removing intact refrigerant from a system and storing it in a sealed external container. This is the easiest way to recapture AC refrigerant and does not require testing or processing.
- Recycling: In the recycling mode, refrigerant is removed from a system and cleaned by separating the oil during a series of passes through core filter-driers. Contaminants, moisture and acidity are reduced during the process, which can be carried out remotely or at a service shop.
- Reclaiming: Reclaimed refrigerant is subjected to a distillation process that restores its purity to new product specifications. It is the only approved method for placing used refrigerant in a different air conditioner. Reclaiming can only be completed at a facility equipped to perform detailed chemical analysis.
The shortfall of AC refrigerant is estimated to be 27.5 million pounds per year by 2015. Since reprocessing will ultimately be the only viable source of additional R-22 in the future, the price of the material is expected to continue to escalate substantially. As older systems become more costly to repair, many consumers will consider replacing existing equipment with units that include a safe and environmentally-friendly refrigerant alternative.
R-410A refrigerant is comprised of pentafluoroethane, difluoromethane and a variety of other additives. Since its active ingredient is fluorine and not chlorine, R410A does not deplete the ozone layer. Originally introduced by Carrier in 1996 under the Puron brand name, R-410A has been used by every major AC equipment manufacturer since 2010. Since there are no significant environmental restrictions in the production of the material, R-410A is readily available and enjoys relative price stability.
Puron and other R-410A products have superior thermal transfer properties, which improves efficiency and can help lower monthly AC operating costs. The refrigerant is produced in abundance, which helps reduce air conditioning repair and maintenance costs relative to equivalent R-22 based systems.
Upgrading to a Carrier or Bryant air conditioner that features Puron refrigerant can help consumers avoid the rising costs associated with servicing aging or obsolete HVAC systems. R-410A is also extremely stable, which has led to improvements in the reliability of standard air conditioners and heat pumps.
Common Sense Approach to Equipment Replacement
Modern air conditioners use much less energy to produce the same BTU capacity as equipment manufactured less than a decade ago. A new energy efficient model with the Energy Star label can save homeowners 10-40 percent on monthly cooling costs. Carrier and Bryant products offer advanced features like a two-stage compressor and Silencer System technology to provide the ultimate in quiet, comfortable performance.
Homeowners with older or failing AC equipment may want to consider purchasing a new system before demand is affected by the scarcity of replacement R-22. Contractors qualified to service both R-22 and R-410A systems can be easily located through the comfort24-7.com website.