Starting in July 2014 we are offering R-49 insulation on our AirScape line whole house fans (R-47 on the 1.7 WHF). These will be separate part numbers (-XR designation) from our standard units. R-49/R-47 insulation will not be available on Kohilo fans.
How do we get R-49 into the doors? A combination of standard fiberglass insulation and VIP panel (vacuum insulation panel) technology. VIP is a relatively new technology that offers an R–Value (thermal resistance) up to ten times greater than commonly used forms of insulation, such as Styrofoam and six times greater than polyurethane. The chart below gives us a visual comparison of VIP panel R values vs. other common insulation on a per inch thickness basis. (courtesy of ThermoCor)
Why not R-49 on Kohilo fans? VIP insulation is relatively heavy and necessitates mechanical actuators to open and close these insulated doors. Gravity dampers used on Kohilos, and a few other fan manufacturers, are not able to handle the added weight of insulation.
If you would like to read more on VIPs, check out the manufacturer’s website: www.thermocorvip.com