AirScape Engineer's Blog

All About Whole House Fans + bonus opinions on energy.

Browsing Posts tagged 2.5e WHF

If you decide to add a remote kit after your initial purchase, the AirScape model, version, and serial number will be required in order to give you the correct remote for your unit. This information is also needed by our technical support staff to diagnose or troubleshoot an issue with your WHF.

Recently we have been using our new and improved sound testing chamber to make sound comparison videos of our different models. The shooting of these videos reminded us that the set up of the ducted models will make a significant difference in the CFM and noise levels. Basically, improper installation will decrease the unit CFM and increase the amount of noise. Some numbers for comparison:

AirScape 4.5 improper installation -  high 59 dBA / low 50 dBA

AirScape 4.5 proper installation -  high 55 dBA /low 46 dBA ……A 4 dBA difference!

The photo above shows the correct install dimensions for the 4.5 WHF. You will notice that we have a nice even bend and the ductwork is fully extended (Note that we used an extra length of the provided chain to help support the bend). It is important to maintain the 20″ diameter of the duct through the 90 degree bend. This will ensure that you get unrestricted airflow through the duct and will help disrupt the sound waves. You also want to make sure the duct and fan are fully extended from the 90 degree bend. This moves the fan to the furthest point from the grill opening, thus decreasing the decibel level.

Airscape 2.5/2.5e installation: The install dimensions for the AirScape 2.5/2.5e are very similar. The duct should be 21″ from the attic floor. It should extend 44″ from the 90 degree bend to the fan (you may be able to extend it to 48″ if the bend is supported as shown in the photo above). The top of the fan should be 44″ from the attic floor.

2.5e Control Board v3.0Not only does the AirScape 2.5e have phenomenally low energy use, the user can also select up to 5 different CFM settings. The 2.5e fan motor has inputs which we program at different CFM. From the factory it is set for a low speed of 1512 CFM at 42 watts and a high speed of 2536 CFM at 196 watts. Now let’s say that the factory low speed setting does not provide enough airflow to properly cool your home over night. The fan speed settings can easily be adjusted for more airflow. For example, you could change the low speed from 1512 CFM to 2080 CFM. At the same time you could also adjust the high speed setting so that the fan will move 2604 CFM on high (see example #2). This is as simple as moving the low and high speed wires on the 2.5e fan control board (located on the fan housing) to different connections. The fan speed adjustment is described below:

  1. Turn your 2.5 e off. Unplug the fan power cord and turn off power to the damper box by unplugging it or switching the circuit breaker off if hardwired.
  2. Remove the fan junction box cover (located on the fan housing).
  3. Move the low and high speed wires to different taps to adjust fan speed (see photos).
  4. Plug in the fan power cord and turn the damper box power back on.
  5. The unit is now ready to operate at the new CFM settings.

ECM_Module_v3.0_cut_1factoryECM_Module_v3.0_cut_1ex1ECM_Module_v3.0_cut_1ex2ECM_Module_v3.0_cut_1ex3

TAP CFM WATTS
TP1 1512 43
TP2 2080 108
TP3 2536 197
TP4 2604 216
TP5 2778 258