Fsi Oil and Propane Has an Eye for HVAC Design

One of the most important aspects of HVAC system installations is the design of the system itself – more specifically, the ductwork that carries the warm or cool air throughout your home needs to be sized correctly in order to operate efficiently and optimally. The industry standard for sizing ducts is called Manual D, a method developed by the Air Conditioning Contractors of America and used across the HVAC industry, and is required by residential building codes. A Manual D method involves:


  • Determining air flow requirements: Each room in your home requires a different amount of air flow, and a sizing calculation will ensure that the duct’s design and materials meet those requirements.
  • Controlling noise level: When air moves through the ducts, it can get noisy. Making adjustments to the ducts help reduce the noise – done often by switching out ducts for more favorable, noise-reducing duct materials.
  • Sealing the ductwork: Leaks account for significant energy losses, when it comes to enhancing efficiency, sealed ducts can go a long way.
  • Insulating where necessary: Ducts can also lose energy when portions of the system are installed in unconditioned areas of your home, such as an attic, crawlspace or basement. In these cases, ducts should be insulated to reduce further losses to conduction


It may or may not be clear why duct sizing is so important, but the truth is that many problems can arise with improperly sized ductwork. If the ducts are the wrong size then the wrong amount of air will enter the room and may cause:


  • The room to be too warm or too cool
  • The air to be too drafty
  • The air to be too noisy
  • The air to be too slow – will not circulate or mix well in the room
  • The fan to work harder, possibly fail sooner, and use more energy to move air
  • The furnace or air conditioner safety devices to stop equipment operation
  • Pressure differentials that may increase energy costs by pushing out conditioned air or drawing in unwanted air


Luckily for homeowners, the calculations involved with sizing the ductwork isn’t something they have to understand or work with because Fsi Oil and Propane’ technicians are well trained in proper HVAC design and installation. If you’ve noticed any issues with your HVAC system’s performance or efficiency, call or contact Fsi Oil and Propane today.