Exhaust fan and evaporative cooler sizing in dry cleaning plants

Almost all dry cleaners use evaporative coolers, or swamp coolers as some call them, in their plant or laundry area. Using refrigerated air conditioning would be too expensive for them. Their steam boilers emit millions upon thousands of BTUs of heat into the work area. Removing that much heat using air conditioning would cost thousands of dollars per month. Because of this, the dry cleaner’s work area should have an exhaust fan that is capable of performing a complete air change approximately every 1 1/2 minutes. Let me give you an example to help you determine the correct size exhaust fan for your vacuum.

Let’s say you rent space in a shopping center that is 25 feet wide by 80 feet deep. The total square footage of this lease space is 2,000 square feet. foot The front sales area is usually heated and air-conditioned. Then remove from the 2,000 square feet. foot its sales area of ​​25 feet wide by 15 feet deep which makes a total of 375 m2. ft. This leaves you with 1,625sq. ft. The boiler room is 10 feet by 10 feet (100 square feet) and the bathroom is 6 feet by 6 feet (36 square feet), adding another 136 square feet. pie is generally not included in the refrigerated area. This gives you a final total of 1,489 square feet. foot of floor space in work area for ventilation and cooling. To get the cubic feet of the work area, you need to measure from the floor to the roof deck. I say roof deck because I never recommend installing a roof over the work area. This just keeps the heat lower in the room and makes the work area that much hotter. Multiply the 1,489 square feet. foot for the 15 feet from the floor to the roof deck and you get a total of 22,335 cubic feet of exhaust area. Divide 22,335 by 1 ½ (the number of minutes per air change) to get the total number of cubic feet of air to remove each minute, or CFM. Under these conditions, you would install an exhaust fan rated at approximately 15,000 CFM. The most common exhaust fans used in dry cleaners are from Grainger. There are Grainger stores in most major cities in the United States, making it convenient to shop for fans and parts. I have purchased exhaust fans from Grainger for years. I learned of a way that any Grainger customer, even if they’ve never bought from them before, can get 10% off their fans. If you email me, I’ll let you know how you can get the discount at any Grainger store across the country.

Next, you need to compensate for the expelled air with an evaporative cooler. These work great in dry weather areas. But even in more humid areas they give some freshness. You may only get a 10-degree temperature drop in a humid area, but on a 95-degree day, a light breeze of 85-degree air can feel good while you’re working on a hot press. In a dry cleaning plant, you’ll usually find them using a large commercial evaporative cooler. For the work area I calculated above, I would need to install a 15,000 CFM chiller. Keep in mind that when you look at chillers they usually give the free air CFM ratings. Since you will probably have a duct system that cools the work area, there is static pressure or restriction in the airflow of the cooler. If you use a 15,000 to 16,000 CFM evaporative cooler, you will probably have a good match with the 15,000 CFM exhaust fan. Static pressure from the ductwork will typically reduce the CFM rating by a couple of thousand CFM. The reason this combination is good is because you want a small amount of negative pressure in the work area, in other words a little more air leaving the room than is being supplied to the room. The most common evaporative cooler used in dry cleaning work areas is the Champion 14/21 SD or the Essick 14/21 SD. These are the most common because they are the cheapest models that are sold. If you’re willing to spend a little more money, I recommend going for a cooler that will last much longer. The Champion AS150 or Champion AS15012 are better built and more durable coolers. If you want a better explanation of why they are better Coolers, you can type these Coolers into a search engine and find articles written about them.

I know there is a lot of technical information out there that would be boring to many people, but if you want to cool down a dry cleaning plant, I highly recommend using this information. I have installed exhaust and cooling systems at Cleaners for decades in the Dallas/Fort Worth, Texas area. These formulas and equipment have worked very well. I hope these tips I have learned will help others in the future.