Researching common HVAC terms

Purchasing a new HVAC system can be overwhelming. It’s a big purchase that has a large impact on your family’s comfort. Making informed purchasing decisions and getting the best performance from your home’s system is easier when you know common HVAC terms.

Tonnage

A ton is the cooling capacity or size of an air conditioning system. One ton is equal to the amount of heat required (288,000 Btu) to melt one ton of ice in a 24-hour period. A one-ton air conditioner is rated at 12,000 Btu per hour (288,000/24). A two-ton unit would be rated at 24,000 Btu per hour. Typical residential central heating systems provide up to 5-tons of cooling. Commercial systems can range anywhere from small, three-ton rooftop units, to 1,500-ton chiller systems. Why a ton of ice? The term is left over from the days before mechanical cooling when ice was an essential part of refrigeration.

SEER

The efficiency of air conditioners is often rated by the Seasonal Energy Efficiency Ratio (SEER) which is defined by the Air Conditioning, Heating, and Refrigeration Institute as the cooling output during a typical cooling season divided by the total electric energy input during the same period. The higher the SEER, the better the energy performance, and the more money you can save.

Indoor air quality (IAQ) 

Indoor air quality is the air quality within and around buildings and structures. IAQ is known to affect the health, comfort, and well-being of building occupants. Poor indoor air quality has been linked to sick building syndrome, reduced productivity, and impaired learning in schools. Health effects from indoor air pollutants may be experienced soon after exposure or, possibly, years later. Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the area. High temperatures and humidity levels can also increase concentrations of some pollutants. There are many products available that can improve IAQ, so be sure to let you HVAC professional know about any issues you are having.

Refrigerant

Refrigerant is the compound (working fluid) used in air conditioners, heat pumps, and refrigerators to transfer heat into or out of an interior space. This fluid boils at a very low temperature enabling it to exude and absorb heat. R-22 is the old standard for residential air conditioners, now being phased out. Most residential air-conditioning units contain the standard R-22 refrigerant. Jan 1 2020, R-22 will no longer be produced or imported. After 2020, only recovered, recycled, or reclaimed supplies of R-22 will be available. The production (not use) of R-22 is being phased out. You are not required to stop using R-22 air conditioners nor to replace existing equipment.

The phase-out period provides time to switch to ozone-friendly refrigerants when you normally would replace your air conditioner. In the future, R-22 supplies will be more limited and costs to service equipment with R-22 may rise.

A chlorine-free refrigerant that meets the U.S. EPA’s newest, most stringent environmental guidelines. R-410A was developed as an alternative to R-22, which will be phased out over the coming years in response to international environmental concerns. R-410A contains no chlorine, so it’s not damaging to the atmosphere’s ozone layer. As an added benefit, laboratory analyses and independent testing have shown that R410A allows higher heat transfer than R-22, resulting in more efficient operation. So, choosing an air conditioner with R-410A not only makes sense environmentally – it also makes sense from an economic standpoint.