How does air flow and static pressure affect a fan?
The relationship between air flow and static pressure of a fan is shown in the graph above. As you can see, air flow and static pressure have a negative correlation. When air flow increases, static pressure decreases; and when static pressure increases, air flow decreases. The 3 points depict possible scenarios where the fan will perform.
Why is the air pressure in my AC too high?
High pressure when the engine is off When there is higher than normal air pressure if the engine isn’t running, this means that there is high pressure in the condenser fan, which is what cools the AC system by passing air through it. This high pressure is commonly caused by two problems:
What should my air conditioner low pressure be?
Use your air conditioning gauge set to check for adequate levels on both sides. You will attach the low-pressure gauge to the low-pressure fitting and vice versa. On the low-pressure side, you should see readings near 30 PSI when the temperature outside is 90 degrees or less.
Is the exhaust fan inter locked with make up air unit?
Exhaust fan operation is typically inter-locked with the roof-top make-up air unit. This inter-lock is checked.
What makes a low pressure fan low pressure?
Free space, open intake and exhaust grilles, and even clean dust filters present MUCH lower air flow resistance and are considered “low pressure” applications where you use the fan types designed for max air flow.
What should the low side of the air conditioner pressure be?
The low side pressure in your air conditioning system should drop down significantly when your engine is running and your AC compressor is cycling on. When the compressor shuts off or you turn your car off the pressures in the system will equalize between the high and low side so the low side pressure will read much higher.
High pressure when the engine is off When there is higher than normal air pressure if the engine isn’t running, this means that there is high pressure in the condenser fan, which is what cools the AC system by passing air through it. This high pressure is commonly caused by two problems:
The relationship between air flow and static pressure of a fan is shown in the graph above. As you can see, air flow and static pressure have a negative correlation. When air flow increases, static pressure decreases; and when static pressure increases, air flow decreases. The 3 points depict possible scenarios where the fan will perform.