You can test it either way. Normally you positively pressurize the duct. That way you can introduce theatrical smoke at the fan inlet and see where it leaks out. However, if you were using it in conjunction with a blower door, there are times you may wish to negatively pressurize it so you can determine leakage relative to locations that may not inside the pressure boundaries.
That is one way to look at it. The other way to look at it: If ductwork was not installed so poorly (generally 30-35% leakage) over the years, they would not need to add something to the energy code to have a 3rd party come behind our industry to test our work.
Does the Fan run in suction mode or Blow through mode?
What happens if you are blowing air to the duct?
You can test it either way. Normally you positively pressurize the duct. That way you can introduce theatrical smoke at the fan inlet and see where it leaks out. However, if you were using it in conjunction with a blower door, there are times you may wish to negatively pressurize it so you can determine leakage relative to locations that may not inside the pressure boundaries.
What's the name of testing equipment in your hand...?
The device in Joe's hand was a manometer.
Txv
Another cost to pass on to the customer. Been doing this for 20 years and gets worse every year. A HVAC system is the price of a new car.
That is one way to look at it. The other way to look at it: If ductwork was not installed so poorly (generally 30-35% leakage) over the years, they would not need to add something to the energy code to have a 3rd party come behind our industry to test our work.
Is that a plug in the lower coil trans or a hole?
It is a hole for duct static testing and training.
Luv dat Joe!