Connecting the Fan Filter Housing to House Exhaust
We recommend the use of an air gap or “THIMBLE CONNECTION” to provide safe exhausting of the FS4010 Fan Filter Housing.
The house exhaust system is subject to velocity and flow fluctuations due to the fact that it is exhausting many areas that have constantly changing demands. The “Air Gap” thimble connection provides a simple way to isolate pulsations occurring in the house exhaust system. The use of an “Air Gap” thimble connection stabilizes the air flow in the Vented Balance Safety Enclosure™ by preventing the fluctuations that exist in the house exhaust system from affecting or disturbing the airflow in the Vented Balance Safety Enclosure™. In addition, the “Air Gap” thimble connection prevents the two fans, the fan filter unit with the Vented Balance Safety Enclosure™ and the house exhaust fan, from fighting each other if they were hard connected. Always use an “Air Gap” thimble connection on the discharge for the Flow Sciences fan filter unit when sending filtered air to house exhaust to insure proper performance of the Vented Balance Safety Enclosure™.
Since the FS4010 has a built-in fan downstream from the filter, the connection should be made with a thimble (FS2083) which has been designed to fit over the square discharge of the fan filter housing. The thimble is 5 7/8” in diameter. Once the thimble is in place, it is connected to house exhaust with 6” diameter flex duct.
If the FS4010 is exhausting 100 CFM, we would set the General House Exhaust to 115 CFM. The purpose of this is to prevent fluctuations in the general exhaust from adversely affecting the performance of the enclosure.
For additional information or questions please call us at 1-800-849-3429.