Why is a properly sized HVAC system important?

Why is a properly sized HVAC system important?

  • Efficiency: You wouldn’t purchase a jet airplane to get to the other side of town, right? It would not address the need directly and it would cost a fortune to run and DSC07760maintain. The same is true for your heating, cooling, and ventilation system.If your system is oversized as many are in residential projects, it means that you are paying more than you need to maintain the air temperatures in your home. Your goal should be to get a system that is right sized. If the right sized system runs for an extended period of time, it will filter air and control humidity, while maintaining the comfort levels in your home. This right sized system will cost less to install and to operate.
  • Comfort: No matter what you have heard, bigger is not better when it comes to HVAC systems. An over-sized air conditioners will not dehumidify the air inside your home. The typical air conditioning units need 10 minutes of running before the coils get cold enough to cause condensation. This the needed to dehumidify the air in your home. If the system is oversized, the thermostat will be satisfied in under 10 minutes (short cycling) well before the unit is able to remove a significant amount of moisture from the air. This creates a cold, clammy condition that is not comfortable. A right sized air conditioner should produce relative humidity levels of less than 50%  in the cooling season inside your home. This will improve your indoor air quality and feel more comfortable. Heating season comfort is also impacted by over-sized heat pumps. They produce supply air that is roughly 100 degrees, compared to furnaces that produce supply air that is 125-135 degrees. The result is a heat pump having to move more air around the house to deliver the needed amount of heated air. If a heat pump is oversized, more air than is necessary will be moving around the house, creating drafts, and causing complaints about comfort or causing you to turn up the thermostat. Heat pumps should be right sized based on the insulation, orientation, air leakage, windows, and size of the home.Triple C Camp - NEST Rebuild, 2010
  • Air quality: If your system is over-sized and therefore not properly dehumidifying, you’ll most likely have moisture problems. This could result in strange smells, mold or mildew growing in areas that don’t receive much air flow, excessive presence of dust mites, etc. Air quality will be impacted unless the system is right sized.