March 25, 2019
Frequently Asked Questions about HVAC
Q. What does HVAC stand for?
A. HVAC (often pronounced “AYTCH-vack”) stands for Heating, Ventilation and Air Conditioning. It refers to equipment or systems designed to keep buildings comfortable by warming, cooling and circulating the air inside of them.
Q. Why should I replace a functioning HVAC unit?
A. Just because a unit is working doesn’t mean that it’s working well. A 15-or 20-year old HVAC system may still be keeping your building cool in the summer, but is using much more electricity to do so than a new unit would. The older system may have been efficient for its time, but has certainly lost some of it over the years. And even the most efficient equipment of that era can’t compare to the technology on the market today. Replacing an older system now – even if it’s still running – will start paying off immediately in energy cost savings.
Q. What is a “ton” in measuring air conditioning?
A. When air conditioning contractors talk about how many “tons” a system might be, they’re not referring to its weight (although the term supposedly came from the amount of energy needed to melt a ton of ice). Tonnage in air conditioning refers to the amount of heat the system can remove from a room in one hour. Each ton of air conditioning can remove 12,000 British Thermal Units, or BTU, per hour.
Q. What are EER and SEER ratings?
A. EER stands for Energy Efficiency Ratio and is a traditional way of measuring an air conditioner’s efficiency. The higher the EER number, the more efficient the equipment. EER is calculated by dividing the number of watts in the unit’s electrical input by the amount of cooling created, as expressed in BTU, under a single set of outdoor temperature (95 degrees F.) and humidity (50%) conditions. Add the word “Seasonal” and you get SEER. Instead of measuring efficiency at one standard temperature like an EER, a SEER measures it using a wide range of temperatures (65 – 104 degrees F.).
Q. Is it better to use an EER or SEER rating in measuring energy efficiency?
A. You can use both. The SEER will provide you with a better indication of how the equipment will perform in varying temperatures during an entire cooling season because it measures energy efficiency over a 39-degree range. On the other hand, the EER will give you a good idea of how efficiently the equipment will operate in extreme heat because it’s calculated at a fixed temperature of 95 degrees F.
Q. Are there minimum EER and SEER ratings for HVAC systems?
A. Yes, but it’s complicated. In 2015, the U.S. Department of Energy replaced its national standards for air conditioning energy efficiency with regional standards, so the minimum requirements depend on what part of the country you’re in. California is grouped in the Southwest region with Arizona, Nevada and New Mexico, where there is a minimum SEER of 14 and a minimum EER of 12.2 for all central air conditioning systems.
Q. Does ENERGY STAR provide certification for HVAC equipment?
A. Yes – the U.S. Environmental Protection Administration’s ENERGY STAR certification program covers a wide range of HVAC equipment, including central and room air conditioning, boilers, furnaces, ventilation fans and heat pumps. Equipment carrying the ENERGY STAR label must meet the program’s strict energy efficiency standards. For example, ENERGY STAR certified central air conditioning systems have higher EER and SEER ratings and use at least 8% less energy than conventional models.
Q. Are air conditioning refrigerants safe for the environment?
A. They are now, but that wasn’t always the case. In the 1980s, popular refrigerants known as chlorofluorocarbons, or CFCs, were found to be harmful to the ozone layer. The federal government banned the use of CFCs in 1996. CFCs were replaced by HFCs, short for hydrofluorocarbons, which don’t contain the chlorine atom that caused the ozone damage. Today’s refrigerants go by alphanumeric designations like R-410A, R-407C and R-134a, but are often sold under brand names.
Q. How can I save even more when I replace my HVAC system?
A. You can enhance the energy savings that new HVAC equipment will give your building by integrating it with an energy management system, or EMS. An EMS will continually monitor temperature and airflow levels throughout your building and automatically adjust the operation of blowers, condensers, compressors and fans to ensure maximum efficiency. These automated systems can also perform diagnostics that alert the building owner or manager to the need for maintenance or parts replacement.