Nearly 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. Your 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.
Suppose you rent space in a shopping center that is 25 feet wide by 80 feet deep. The total square footage of this rental space is 2,000 square feet. ft. Front sales area is typically 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 must measure from the floor to the roof deck. I say roof covering because I never recommend installing a roof in the work area. This just keeps the heat lower in the room and makes the work area much hotter. Multiply the 1,489 square feet. foot times 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) and get the total number of cubic feet of air to be removed each minute, or CFM. Under these conditions, I would install an exhaust fan with a power rating of approximately 15,000 CFM. The most common exhaust fans used in dry cleaners are those from Grainger. There are Grainger stores in most major cities in the United States, making it convenient for buying fans and parts. I have bought exhaust fans from Grainger for years. I learned of a way that any Grainger customer, even if they have never purchased 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 make up for the exhausted air with an evaporative cooler. These work very well in dry climate areas. But even in wetter areas they give some coolness. You might only get a 10-degree drop in temperature in a humid area, but on a 95-degree day, a light breeze of 85-degree air can feel good while working over a hot press. At a dry cleaning facility, 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 CFM ratings in free air. Since you will likely have ductwork cooling the work area, there is static pressure or restriction in the airflow from 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. Duct static pressure will typically reduce the CFM rating by a couple 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 sold. If you’re willing to spend a little more money, I recommend going for a cooler that will last a lot 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 that would be boring for many people, but if you want to cool down a dry cleaning plant, I highly recommend using this information. I have installed exhaust and refrigeration systems at Cleaners for decades in the Dallas/Fort Worth, Texas area. These formulas and teams have worked very well. I hope these tips I’ve learned will help others in the future.
