There’s no better way to effectively cool a large store than by installing commercial exhaust fans. Let’s be real, once you surpass 2400 square feet, your options become limited. Sure, you could go with an AC unit, but that involves hefty upfront costs for the hardware and insulation, not to mention ongoing operational and maintenance expenses. Another option is using large “ceiling fan” solutions like Big Ass Fans (which we haven’t reviewed). However, sometimes all you need is a simple solution to remove the warm air from your store. That’s where installing exhaust fans high up on the eaves comes in, allowing the warm air to escape while drawing in cooler air from below. In this article, we’ll guide you through the process of installing a commercial wall exhaust fan, which can significantly reduce the temperature in your workshop or large garage.
Choose Your Commercial Wall Mount Exhaust Fan – AirFlow
To ensure you select the right fan for your space, you first need to determine how many fans you’ll need to effectively circulate the air. Divide the cubic footage of the room by the number of minutes it takes for an air change. Here’s the formula to calculate the required CFM (cubic feet per minute) capacity for your fan:
- Room size (cubic feet) / air change (minutes) = CFM
- Room size (cubic feet) / CFM = air change (minutes)
For instance, let’s assume our store is 2,400 square feet with an average ceiling height of 14 feet, totaling approximately 33,600 cubic feet. If we want to achieve an air change every 10 minutes, we’ll need a fan with a CFM rating of around 3,360 CFM (assuming 1/8″ SP (static pressure)).
Now, we might be a bit excessive, but we have enough room for a larger fan. Therefore, we settled on a Canarm 36″ Standard Exhaust Fan (Model SD36-G1D). This model can move 8000 CFM with a static pressure of 0.125 inches, which means it cycles the room every 4.2 minutes:
- 33,600 cubic feet / 8,000 CFM = 4.2 minutes
Canarm Wall Mounted Exhaust Fan Features
- Available in sizes ranging from 8″ to 48″ (150 – 15,300 CFM)
- Single speed, two-speed, and variable-speed models available
- All fans equipped with fully enclosed, thermally protected motors
- Rugged steel welded box housing with durable powder-coated finish
- Aluminum louvers supported by long-life nylon bushings (30″, 36″, 42″, and 48″ models have PVC louvers)
- 8″ – 24″ models feature thick line chrome OSHA guards on the intake side (30″, 36″, 42″, and 48″ models have gray powder coat guards)
- All fans come fully assembled
Preparing the Wall
Since our attic lacks insulation, prepping the area becomes easier for us. We opted to cut the hole from the inside. However, we encountered difficulty because the previous workers had nailed the exterior vinyl siding at the bottom, making removal and cutting a challenge. To overcome this, we drilled four 1″ holes using a Bosch Daredevil spade bit. With a thin metal blade and fine teeth, we used our trusty Milwaukee M18 Super Sawzall to cut the hole.
Once we achieved the desired square shape, we cut a top flat header and bottom saddle from 2×6 pine. These pieces provide the necessary clearance for the fan body. Our aim is to securely attach it to the shop’s frame without it protruding. We used the Makita 18V Brushless Circular Saw to speed up the process of cutting the boards.
Next, we cut the middle stud, allowing the newly made flat head and saddle 2×6 to fit perfectly into place. Once we ensured everything was level and nailed down, we achieved a highly secure attachment point.
To complete the installation from the outside, we used DAP DynaFlex Ultra window and door sealant to caulk the J-channel to the frame of the commercial wall exhaust fan. Luckily, the height of our shop was not an issue since we had the convenience of a Little Giant Hyperlite Ladder ─ one of the best ladders in our store.
Wiring It Up
Our fans only required about 6.6 amps of 120V power. Once the installation was complete, we ran the wiring to the fan location and installed a 2-hour timer switch. This switch allows us to turn on the fan without worrying about leaving it running overnight when we close the shop. Additionally, it prevents the fan from running for an extended period with the oversized 14×18 shop door closed, which would cut off the main source of air.
While air conditioning systems may be effective in cooling a store and creating a comfortable working environment, cost is a crucial factor to consider. Wall-mounted exhaust fans provide a cost-effective solution while ensuring adequate airflow. With the right-sized system, you can quickly remove hot air from your store and bring in cool air from below. Although the installation process may seem daunting, with the right tools and attention to detail, it becomes much more manageable.
Additional considerations for mitigating heat in large unconditioned spaces include:
- Installing radiant barriers to control heat buildup
- Adding insulation (which may include elements of radiant barrier systems)
- Exploring limited air conditioning solutions that directly bring airflow to your workplace
- In drier climates, a “swamp cooler” system might be beneficial, depending on your work type and materials used.
For more information on Canarm exhaust fans, you can visit their website here.