A properly installed HVAC system serves a multitude of roles – whether it’s maintaining a comfortable temperature within your home or ensuring proper humidity levels, everyone strives to have a HVAC system that works properly. However, this ideal is incredibly difficult to achieve without a proper HVAC design, which includes a Manual J (Load Calculation), Manual S (Equipment Selection), Manual D (Duct Design), and Manual T (Air Distribution).
- Manual J (Load Calculation)
- After considering the home’s location, insulation values, square footage, window specs, etc., a Manual J calculation can be conducted to calculate the heating and cooling loads of the home. Each home is unique when considering all these factors, so conducting a Manual J on each individual home is imperative to ensure accurate results.
- Manual S (Equipment Selection)
- Once the heating and cooling loads of the home are known, equipment selection is conducted to determine what size equipment is needed. Rules of thumb using square footage are commonly used and frequently lead to discomfort and high humidity.
- Manual D & T (Duct Design and Air Distribution)
- Equipment sizing has been completed, now one must determine how to properly distribute the heating and cooling throughout the home. To do this, a Manual D and Manual T are conducted to determine what size ductwork is needed and how ductwork will run to distribute the air throughout the home to ensure comfortability.
After the full HVAC design is conducted, commissioning is needed to bring the design to fruition. Making sure duct lines are installed correctly, including making sure duct lines are pulled tight and reducing any excess length as well as avoiding compression and tight turns, is extremely important, along with complete duct sealing to reduce duct leakage. After this is completed, a round of diagnostic testing and balancing is conducted to ensure proper installation and proper air flow directed by the design.
Conducting a full HVAC design does not only benefit the homeowner; it benefits the home builder equally if not more so. Lawsuits against HVAC contractors has been on the rise, primarily due to either faulty installations or oversized units. Conducting a full HVAC design and commissioning ensures that builders have appropriately sized and installed the duct system specifically for the home being built and provides quality assurance to reduce the amount of call backs attributed to HVAC systems.
