Fall is upon us friends…the rustle of the leaves across my driveway, the brisk chill in the air…mmm, pumpkin pie. There are some things that can be done this time of year that can keep you more comfortable and save some money to boot.

• Change or Clean Furnace Filters…This should be done at least 3 times per year to help keep the airflow path clear so the blower motor doesn’t have to hard too hard to distribute air. As you likely have seen, after a summer of open windows the filter has taken a beating and is covered with dust and debris.

• Seal the ducts. It has been calculated that roughly 30% of your annual energy costs literally fly out the window due to loss in poorly sealed or even disconnected ducts. You can visually inspect the duct work for tears, and check all connections to ensure they are tightly sealed. If they are not, some Foil Back Butyl Rubber tape will go a long way towards recuperating heat or money.

• Clean your dryer duct and inspect the lint screen. Lint build up can impede airflow out of the dryer, decreasing performance and creating the potential for fire.

The choices to control your fan vary as widely as the choice of fans.

Here are some of the more common ones and a few typical uses:

• Timers. These are usually countdown timers that allow you to leave the fan running after you are done in the bath to ensure all the moisture is gone. These are also nice given how quiet the inline remote fans are. BONUS: If you are using a single fan to vent two baths, these timers make it very easy to install switches in each bath. Here is a wiring diagram:

• Speed Controls. These are fairly self explanatory, they allow you to adjust the speed of the fan itself. Typically used in kitchens because the ventilation needs vary by what you are doing, we have also used them in Duct Boosting applications to set the fan at the most efficient setting for the job. We have ones that look great and those that didn’t go to prom, as well we have models that will take quite a bit of voltage.

• Themostats. We use these to turn on attic fans as well as garage fans when temperatures build up. The most popular use is actually in A/V applications. We have a model that will switch high voltage (110v) so that eliminates the need for relays and ancillary wiring.

• Humidistats. These are used to measure moisture content in the air and turn on a fan to vent an area. Usually under a home, or in a barn or other outbuilding. These are nice, because they do the remembering for you, so you needn’t worry about whether the fan was turned on.

A concern shown by many clients is quiet operation of whichever fan unit they are purchasing. Remote fans clearly will assist with this as the fan is not located directly above you. There are other factors that can help with a quiet installation.

For bath fans, try to get at least 5-8 feet of flexible insulated duct between the fan and grille. We have found this ducting does a great job at minimizing noise and vibration transmission.

Kitchens are bit tougher since any fan moving the volume of air that they do will be louder. Typically a Fantech Silencer will assist in this matter quite well. Distance will also be your friend on these as the fans can typically be mounted anywhere in the duct run. Also, try to get a couple bends in the pipe between the fan and the kitchen. This will help bounce the sound waves back to the discharge side, and help keep things quiet.

For those of you doing general ventilation, boosting your HVAC airflow and other tasks, you can use a combination of the above and use a couple of the following:

If you are trying to boost airflow at a particular register, try to keep the fan back from the register by a few feet if possible.

Those with rigid duct would do well to replace a section around the fan with flex duct to help absorb some noise.

The use of a speed controller can help quiet a fan as well. You can purchase a fan with a little more power than you need and dial it back to suit your need.

One of my favorite activation methods for remote duct booster fans is a pressure sensing switch. The pressure switch has a distinct advantage over hard wiring, since you do not have to pull new wires from the main fan unit to the remote mounted fan.  This saves you time and money on installation.

The pressure switch works by sensing the pressure increase in the duct from the central fan activating. The switch diaphragm is able to sense extremely small pressure increases (approximately 0.05″ – 0.07″) which then activates a single pole, single throw snap switch that starts the duct booster fan.

The pressure switch is connected by means of a pressure tap that is either a section of flexible tubing, such as used by the Fantech DB10, or a short direct barbed tap, as used by the Tjernlund PS1503, that can be inserted into the duct or plenum. In the case of very long duct runs, the tap should be placed “upstream” of an elbow in order to take advantage of the temporary pressure build up before the elbow due to the resistance of the bend. The switch can be conveniently installed near the booster fan localizing and limiting the amount of area disturbed by the upgrade.

Tjernlund Pressure Switch

All in all, the pressure switch is an easy and quick option when installing you duct booster fan.