Education - The ABC's Of HVAC
Your definition of “comfort” may be different from your neighbor’s, and understanding some key terms can help make your search for improved heating and air conditioning efficiency and performance less confusing…and more effective.
Advanced Reciprocating Compressor – a type of compressor that uses a more efficient process for compressing refrigerant for better cooling efficiency.
AFUE – (Annual Fuel Utilization Efficiency) tells how much energy is being converted to heat. For example, an AFUE of 90 means that 90% of the fuel is being used to warm your home, while the other 10% escapes as exhaust with the combustion gases.
Air Handler – is a device used to condition and circulate air as part of a heating, ventilating, and air–conditioning (HVAC) system. An air handler is usually a large unit that resembles a furnace, runs off electric and is usually used residentially with Heat Pumps.
BTU – (BritishThermal Unit) Used for both heating and cooling, BTU is a measure of the heat given off when fuel is combusted. Or for cooling, it’s a measure of heat extracted from your home. One BTU is equal to the heat given off by a wooden kitchen match.
Capacity – the amount a heating or cooling system takes to heat or cool a given amount of space. For heating, this is usually expressed in BTUs. For cooling, it is measured in tons (12,000 BTU’s in a ton of cooling).
Carbon Monoxide (CO) – an odorless, colorless and toxic gas. Because it is impossible to see, taste or smell the toxic fumes, CO can kill you before you are aware it is in your home. At lower levels of exposure, CO causes mild effects that are often mistaken for the flu. These symptoms include headaches, dizziness, disorientation, nausea and fatigue. The effects of CO exposure can vary greatly from person to person depending on age, overall health and the concentration and length of exposure.
Condenser Coil – the high pressure high temperature refrigerant gas leaves the outdoor compressor and enters the outdoor condensing coil where it is cooled to a liquid state by the condensing unit fan that blows outside air across the condensing coil or by immersion of the condensing coil in cooling water in some designs. The heat produced in these steps is transferred to the outside by a fan which blows outside air across the condensing coil. The liquid refrigerant is then able to return to the indoor components for cooling and dehumidifying the building interior.
Digital Thermostat – is an electronic thermostat powered by electric, battery or both. It has digital screen which displays temperature and other information. It’s accurate to +/–0.1°C. It ensures reliable and efficient temperature regulation and can be either programmable or non–programmable.
Downflow – a type of furnace that takes cool air in from the top, heats it and blows warm air out of the bottom—common when a furnace is located in a slab home.
ECM – (Electronically Controlled Motor) is an ultra–high efficient DC driven motor, which is much more efficient than an AC motor. This allows you to circulate and filter the air in your home continuously for about the same cost as operating a standard light bulb.
Electronic Air Cleaner (EAC) – filters out large particles and contaminants from indoor air. It then electronically pulls out tiny particles that have been magnetized, such as viruses and bacteria, drawing them to a collector plate.
Load Estimate – a series of studies performed to determine the heating or cooling requirements of your home. An energy load analysis uses information such as the square footage of your home, window or door areas, insulation quality and local climate to determine the heating and cooling capacity needed by your furnace, heat pump or air conditioner. When referring to heating, this is often known as a Heat Loss Analysis, since a home’s heating requirements are determined by the amount of heat lost through the roof, entry ways and walls.When referring to cooling it’s considered a Heat Gain.
Evaporator Coil – part of a split–system air conditioner or heat pump located indoors. The evaporator coil cools and dehumidifies the air by converting liquid refrigerant into a gas, which absorbs the heat from the air. The warmed refrigerant is then carried through a tube to the outdoor unit (condenser coil).
Fan Coil – an indoor component of a heat pump system, used in place of a furnace. It provides additional heating through electric elements on cold days when the heat pump cannot provide adequate heating.
Freon – a trademark used for a variety of nonflammable gaseous or liquid fluorinated hydrocarbons employed primarily as working fluids in refrigeration and air conditioning and as aerosol propellants.
HVAC – term used for Heating, Ventilation, and Air Conditioning.
HSPF – (Heating Seasonal Performance Factor) is a measure of the heating efficiency of a heat pump. The higher the HSPF number, the more efficiently the heat pump heats your home.
Horizontal Flow – a type of furnace, installed on its “side,” that draws in air from one side, heats it and sends the warm air out the other side. Most often used for installations in attics or crawl spaces.
Humidifier – a piece of equipment that adds water vapor to heated air as it moves out of the furnace. This adds necessary moisture to protect your furnishings and reduce static electricity. Humidity levels should range from 35–50%.
Matched System – a heating and cooling system comprised of products that have been certified to perform at promised comfort and efficiency levels when used together, and used according to design and engineering specifications.
Natural Gas – This energy fuel is a mixture of naturally occurring combustible gases found underground and is widely used for heating and cooking, as well as for a variety of industrial applications.
Operating Cost – the day–to–day cost of running your home comfort equipment, based on energy use.
Payback Analysis – is the overall measure of the efficiency and value of your home comfort system. By combining your purchase price and ongoing operating costs, a payback analysis determines the number of years required before monthly energy savings offset the purchase price.
R410A Refrigerant – an environmentally sound refrigerant designed to protect the earth’s ozone layer. Federal law requires all manufacturers phase out ozone depleting refrigerants within a certain date. It is approved by the US Environmental Protection Agency as a replacement for Freon 22*.
SEER – (Seasonal Energy Efficiency Ratio) is a measure of the cooling efficiency of your air conditioner or heat pump. The higher the SEER number, the more efficient the system is at converting electricity into cooling power.
Setback Thermostat or Programmable Thermostat – a thermostat with built–in memory, can be programmed for different temperature settings at different times of the day.
Scroll Compressor – a special designed compressor that works in a circular motion, as opposed to up–and–down piston action. It has fewer moving parts and provides smooth, efficient and reliable operation.
Split System – refers to an air conditioner or heat pump that has components in two locations. Usually, one part of the system is located inside (evaporator coil) and the other is located outside your home (condenser coil).
Two–Stage Furnace – is a furnace that can operate on both low and high heat settings. Low heat is typically used around 80% of the time. Low stage heat has a lower BTU output and runs quieter.
Upflow – a type of furnace that draws air in from the bottom, heats it and then blows the warmed air out the top into the duct work. This type of furnace is usually installed in a basement or an out–of–the–way closet.
Ventilator – a ventilator captures heating or cooling energy from stale indoor air and transfers it to fresh incoming air.
Zoning – a way to increase your home comfort and energy efficiency by controlling when and where heating and cooling occurs in a home. Thermostats are used to control operating times of the equipment. Dampers are used to direct airflow to certain parts or “zones” of the home.