Energy Source Builder
Humitrak Ventilation Controllers
Tamarack Technologies has developed a line of solid-state ventilation controllers based on an electronic humidity sensor. Humitraks can control exhaust fans or heat recovery ventilators up to a maximum load of 1.8 amps. A "Fan On" indicator glows whenever the fan is running. The control mounts into a typical single-gang electrical box.
Four models are available:
- Humitrak-FS has two fixed relative humidity (RH) set points. The summer setting is 35 percent RH, while the winter is 55 percent. These factory-set points can be changed by special request.
- Humitrak-AS has a knob for adjusting the humidity set point between 30 and 90 percent RH.
- Humitrak-R comes with a remote humidity sensor. This allows the sensor to monitor a remote space, such as a crawlspace or attic, while the control remains conveniently located in the living area. The sensor can be located up to 200 feet from the control.
- Humitrak-D compares the RH in two locations and engages the fan when one reading exceeds the other. This addresses a problem that occurs in wet climates, such as coastal areas, where high humidity may not accurately indicate the need for ventilation. Here's how it might work. You place the main control in a bathroom and the remote sensor in the hallway. Set the control to 50 percent RH. The fan comes on only when the RH exceeds the set point and is three percent above the reading in the hall. That way the control can't be fooled by humidity that is always high.
All four models share several features. There is no "off" position, so the control remains in automatic mode. A manual switch can activate the fan for a preset 12-minute period. Then the fan returns to automatic. A Humitrak can be wired to engage on either rising or falling humidity. That means it can operate as either a humidistat or a dehumidistat. In controlled ventilation systems, it would be wired as a dehumidistat.
Contact:
Tamarack Technologies
This article appeared in Energy Source Builder #39 June 1995 |
