Load calculations are performed to determine what causes heat in your home, where it originates from and why. This is done in order to get the correct amount of cold and hot air to the appropriate places. This calculation is made with a whole home approach, and takes insulation, tightness, roofing, materials, windows, and other factors into consideration. System capacity (size) should ideally be a product of these factors. For these reasons, using general rules of thumb to size HVAC systems can result in inaccurate sizing.

Three Major System Design Factors

All three of the following design guides are important in order to have a system that can create and distributes the required amount of cold air to the proper places efficiently. Air isn’t able to flow properly to the right rooms without appropriately sized and configured ductwork.

• Manual J is the foundation. It identifies cooling and heating need determined by construction and geographical location at certain engineering constants (laboratory conditions).
• Manual RS determines appropriately specified equipment for a specific environment’s needs (when real world is different from the laboratory constants).
• Manual D deals specifically with distribution. Air conditioning capacity is dependent on CFM (airflow) to not only distribute the cold air, but to create the cold air in the first place. For example, you could have 5 tons of cold air for a house needing 5 tons of cold air, but without the right ductwork and airflow, there may only be 3 tons of cold air getting to the rooms within the home.

Adam Schniederjan Air Conditioning, Inc. is known throughout Cooke, Grayson, Denton and Montague counties as the expert in load calculations and duct design/re-design. So if you have a room that is too hot compared to other rooms – give us a call. We’re experts in balancing air flow to all of your rooms!