Residential Duct Balancing: HOW TO?

[HighPotential]

I have manual dampers for each room at the supply plenums. I just have no idea how to balance them. Can anyone recommend an easy step by step process? The entire house is one zone.

Thanks!

 

[HighPotential]

Sorry, meant AIR BALANCING.

 

[iken]

I Take it you know the air flows required in each area.

Start from the furtherest outlet from the supply unit, measure the air flow achieved, and adjust the damper accordingly, repeating this until the desired air flow is acheived.

You then go to the 2nd furtherest from the unit and repeat above, and so forth.

Once all outlets have been done, you can then go and recheck all readings (no further adjustment)

 

[Yeldud]

If you don't know the design air flows or have any way to measure the flow rate, then you normally would balance by temperature. Use a thermometer, and crank up the thermostat. If by some stroke of luck, all rooms experience the same temperature when the furnace is heating or cooling, then the system is essentially balanced, as is. This assumes there is no excessive register noise etc. When the furnace is in a heating mode, the rooms which run the coldest have the lowest air flow in comparison to their requirement. The rooms which run the warmest have the highest air flow in comparison to their design requirement. Make certain the rooms running the coldest have their dampers fully open, and air flow is not otherwise obstructed. Slightly throttle the outlets to the warm running room nearest the cold running rooms first. As you restrict air flow to the warm running room, the cold running room will experience an increase in flow and temperature. This is an iterative process, so you must go to each warm running space successively to throttle the air flow slightly, to force more air to the cold running rooms. As you work through the system, the temperatures in all rooms should begin to equalize, assuming the system and distribution ducts have been sized adequately to start. have fun