An “Air Balance” is a useful process for measuring the performance of a simple or Complex HVAC System, and for providing the occupants with a comfortably conditioned space.
To understand how this process works, let’s first look at the different types of Air Balance by defining the two extremes: Comfort Balance and a Certified Air Balance. A Comfort Balance is simply checking to see whether the room feels comfortably conditioned. It may be as easy as walking from room to room, holding a hand up to the ceiling to see if sufficient air is coming out of the registers, and asking the occupants if they are comfortable. If they are not, your journey starts to discover how to resolve the HVAC problems associated with the situation. It may involve Adjusting/Moving Registers, installing Restrictors/Dampers after the fact, or just insuring the air doesn’t blow directly on an occupant. Many occupant complaints are associated with air circulation: too much and too little.
A Certified Air Balance ensures all components of the HVAC (Heating, Ventilating, Air Conditioning) System are working in harmony, at their optimum performance, providing total occupant comfort. The most important part of the HVAC plans used by the Certified Air Balance company is the list of “CFM” requirements next to each supply, return, intake, exhaust and ventilation opening. Without this important information, a Certified Air Balance is not possible. The actual Air Balancing process includes a number of related tests that determine the performance of your Air Conditioning and Heating system.
Air balancing hoods are used to measure the amount of air at each Diffuser. Manometers measure system pressures. Hygrometers measure System Temperature and Humidity. The results of all these tests are compiled into a report to determine how well your system is functioning. The Air Balance Technician will change all of the Air Filters in the system, and insure that all dampers are fully open. Readings are taken at every opening inside, on the roof, etc. Slowly the dampers are closed in an effort to meet the Design Air CFM requirements detailed in the HVAC plans. Adjusting one Damper changes the air CFM at all other openings. The Air Balance Technician returns to every opening, making new adjustments and readings based on the changes from the previous one. Registers, Grilles, Exhaust Fans, and Fresh Air must all “Balance” to meet the System Performance Requirements.
After the Technician believes the system is all in tune, he locks down all of the Dampers and other devices, so that the settings will not change. While this should keep the System “Balanced,” the System can be thrown out of Balance by such things as Dirty Filters, the occupants changing the Register setting, office remodeling, and redesigning and installing Registers and Ducting.
At US Air Contractors, we check the Static Pressure of your System whenever repairing or planning to replace your Heating and/or Cooling equipment. A familiar comparison is when you go to your doctor, someone always checks your blood pressure. Like blood pressure, Static Pressure is one of the key vital signs of your Heating and Cooling system. This Air Balance test helps our Technicians identify any significant Air Blockage or Air Leakage. With this initial testing along with an in-depth interview, we can recommend the appropriate diagnostic tests followed by recommendations to correct existing issues and optimize your home’s comfort and Energy Efficiency.