Duct system design is a crucial aspect of an efficient HVAC system and they usually are the weak link. Just as with the human circulatory system, ductwork needs to be carefully thought through and sized. Not only does the comfort delivered and the efficiency of the HVAC system depend on it, so does the long-term longevity of the ducts and the equipment.
If the initial installation of the duct system is not properly designed and installed, your HVAC contractors ought to size systems by completing an industry accepted load calculation of the home - such as Air Conditioning Contractors of America's (ACCA) Manual J. They then ought to use the results and a duct calculation design process to size ducts and determine the configuration and capacity of the ductwork. Regrettably, far too often, these essential steps are skipped in the cut throat, low cost environment of most new construction these days. Most homeowners cannot judge the quality of their duct installation and the overall HVAC installation until several years of use which is when the problems start to crop up.
These are the most important considerations for your duct system design that the professionals will take into account:
- Placement - Ideally, whenever possible, the ductwork should go through conditioned spaces to reduce thermal losses.
- Material - Metal ducts are made from galvanized metal and will resist mold growth. Rigid duct board is usually lined with aluminum and can be an alternative to metal. Flex ducts are insulated and easy to install, but if not done so carefully, can be inefficient, hard to seal and may kink or collapse.
- Returns - The supply and return from the blower need to be balanced. Many homes have inadequate return airflow back to the blower, which tends to create uncomfortable rooms and contribute to leak development in the ductwork system.
Listen to the sounds your system makes as it runs. If you hear excessive noise or whistling, it's likely that the supply ducts are too small or have leaks.
You can test the adequacy of the returns by closing all the windows and exterior doors, turning the blower fan on and opening interior doors slightly, one by one. If the air coming through the duct pushes the door open further, chances are you have inadequate return air, air imbalance or the register is blocked. You can remedy inadequate return air by adding vents to a room or shortening the interior doors so that air will move out of the room when the door is closed.
To learn more about duct system design and improving existing ductwork, contact P.K. Wadsworth Heating & Cooling. We've provided outstanding HVAC services for the greater Cleveland area since 1936.Follow @PKwadsworth
Paul Wadsworth is the President and Owner of P.K. Wadsworth Heating and Cooling. For 37 years, Paul has been providing heating and cooling services to the Greater Cleveland area. P.K. Wadsworth has been a trusted Cleveland HVAC service company for over 75 years. The company understand the area's construction and local heating and air conditioning needs. Paul has an MBA from the University of Michigan and a B.S., Industrial Engineering from Purdue University. Paul is the Chairman of COSE's Energy Advisory Council. He's been President of the Cleveland Air Conditioning Contractors of America and a founding member of the local chapter. Paul was born and raised in Cleveland and has been active in the local community. He resides in Cleveland, Ohio with his wife and two sons.
The opinions and statements contained in this article are for general informational purposes only and are not instructions. Only trained, licensed and experienced personnel should attempt installation/repair. The author assumes no liability for the opinions/statements made in this article. Any individual attempting a repair or installation based on this article does so at their own risk of loss.photo credit: Pulpolux !!!