HVAC Terminology

Whether you're a DIY-er or leave all the work to the pros, here are some common HVAC terms explained!

  • SEER (Seasonal Energy Efficiency Ratio) – each air conditioner and heat pump receives a SEER rating, ranging from 13 to 20. The higher the rating, the more energy-efficient the HVAC unit operates
  • Evaporative Cooler - The part of an air conditioner or heat pump that absorbs heat. In an air conditioner, the heat is pushed outside. In a heat pump, the heat is used to heat the home.
  • Ductwork - Air flows through this type of system so that it can be distributed through a home.
  • Humidity - The amount of water vapor that is in the air.
  • BTU - British Thermal Unit –one BTU equals one unit of heat energy. It takes one BTU to raise one pound of water one degree. When a heating unit has a high BTU, this means it has a high heating capacity.
  • Carbon Monoxide - When carbon burns in a home without sufficient amounts of air, an odorless and poisonous gas known as carbon monoxide will be released.
  • Compressor - This is the part of an HVAC unit that pumps refrigerant so that cooling requirements can be met and maintained.
  • Condenser - Part of the air conditioning unit that gets rid of heat. This is most often located outside.
  • Evaporator - This part of an air conditioning unit captures heat and removes it from the part of the unit that needs to be cooled. This is most often located above or below your furnace. Hence the upflow/downflow term.
  • Furnace - A device used in homes to put out heat. It can come as a single unit or be combined with an air conditioning unit, commonly referred to as a central heating and cooling unit.
  • Geothermal heat pump - A type of central heating and cooling unit that takes heat from the ground and uses it to heat a home. This can be a very efficient way to heat your home however can require the most amount of money to retrofit.
  • HVAC - Heating, Ventilation, and Air Conditioning
  • Joule - Basic SI unit of energy.
  • Latent heat -This heat is required to transform a liquid into a vapor or vice versa without changing the actual temperature.
  • MERV Rating - Minimum Efficiency Reporting Value –Filters have MERV ratings, which describes how big the holes are in the filters. A higher MERV rating means the smaller the holes, which translates into higher efficiency.
  • Refrigerant - A liquid/chemical that’s used in cooling units; this chemical gives off a cooling effect, and it is commonly referred to as Freon.
  • Split System - When a home has a HVAC unit that has components located both inside and outside of the home, this is known as a split system.
  • Sensible heat - When a substance is heated and the temperature itself rises; unlike latent heat where the state of substance changes but the temperature does not. We often refer to this as the type of heat that you feel.
  • Static Pressure - The amount of pressure that is exerted on the duct system, but it’s not the pressure coming from any moving air. We use static pressure to measure if the airflow and duct system are undersized.
  • Ton - A unit of measurement that is used to identify the cooling capacity of an air conditioning unit. Here’s a nifty tip- 12,000 btu’s equals 1 ton. And we need approximately 400 CFM per ton. So a 3 ton system is equivalent to 36,000 btus and will need about 1200 CFM for proper airflow.
  • Ventilator - Part of the HVAC system that ventilates the home.
  • Watt - The amount of energy that an HVAC uses. The higher the wattage, the more energy the unit is using. Our power bill shows up with this measurement- referred to as kilowatts.
  • Zoning- This is a method used in homes when different rooms require different comfort zones. Zoning provides enhanced heating and cooling, which translates into optimal comfort and efficiency. Imagine being able to turn certain parts of the house “on” while turning other parts “off”. All seperate from one another.