GLENDALE, Ariz. — It’s a summer day. Would you feel good spending a couple of hours sweating in a restaurant that has no air conditioning?
Or how about spending two hours at dinner in a 50-degree restaurant in the wintertime? Would you want to go back there?
Many Laundromats around the country have not yet realized that they need to keep the inside temperatures comfortable. During summer, fans will only provide minimal comfort. In winter, the nominal heat coming from the dryers can only keep a mat acceptably warm on days when the temperature outside is 40 or warmer. Any lower and the store begins to get uncomfortably cold.
In Part 1, I suggested how to handle your dryers’ makeup air, and options for heating and air conditioning. Let’s conclude by determining how to choose the right heating and cooling system for you.
CHOOSING THE RIGHT SYSTEM FOR YOU
AC installation and operation is expensive but doesn’t cost as much as you may think.
Many AC installation companies don’t know how to properly size up a Laundromat, I believe. They may be aware of heat coming in through windows and doors, lack of insulation, losses from ductwork, and maybe even radiant heat from the dryers, but there’s also heat and humidity from washers, the boiler, as well as that makeup air deficit! An unwitting AC company could easily size your unit at half the size that you really need.
Seek help from your distributor, which has experience with this. I would start by giving it the square footage of the mat, the numbers of washers and dryers, your electric service capacity, and whether you have your dryers sealed off from the customer area or not. Most distributors will be happy to help you.
The more efficient AC units will have variable-speed fan motors, and the top-of-the-line units will even have variable-speed compressors. These units, also called “modulating units,” will usually have the highest SEER ratings.
I believe that we need to strike a balance between efficiency, costs and simplicity.
You can compromise by choosing a two-stage compressor, which will operate at two levels of cooling, depending on the need at the time. If your mat has three-phase service, then go with a three-phase compressor.
If you’re dead-set on the highest efficiency, then look at the warranty closely. It may be worth it to consider an extended warranty.
CONSIDER SPLIT UNITS
Split units are inherently more energy-efficient than packaged central AC (HVAC, or heating, ventilation and air conditioning), because they don’t have the losses associated with ductwork. Their condensers may also be mounted on your building’s wall, whereas HVACs are heavy, roof-mounted units that may require dunnage (steel I beams) to support their weight.
If your unit works well but is undersized, you may want to add a split unit or two for those really hot days. You can try adding some fans but if it’s not cool enough, people will get frustrated. Some will actually open the laundry doors if they feel your store is too hot, wasting your AC.
That said, I was told that it’s actually cheaper to run an AC compressor at a steady rate, rather than have it cycle on and off throughout the day. It’s the startup surge to get the motor up to speed, often under a load, that really draws current. Once the motor gets up to running speed, the amp draw drops significantly.
For good efficiency with less exotic AC systems, you can have your main unit slightly undersized, plus a second unit that kicks in on really hot days when the store temperature rises past the main unit’s cooling capability.
The main unit’s compressor will be on most of the time, thereby reducing energy-wasting spikes. A good, thermally protected compressor will last years with proper maintenance. I say set your main unit at 75 F and your second at 77.
Don’t forget to insulate your AC ductwork as well as the mat itself. Why make that nice, cool air, only to have it heat up five degrees in the ductwork before it even enters your mat? At the least, try painting the ductwork white or silver to reflect sunlight.
I also installed 20-by-20 mesh “No-See-Um” screening over the condenser coils to keep lint out. Regular home screens are not tight enough, I believe. All evaporators have filters or screens but I’m not aware of any condensers that protect their coils with filters or screens. This is necessary in some mat installations where the HVAC is too close to the dryer exhaust.
MAINTAINING YOUR SYSTEM
If your AC is properly sized but isn’t cooling well, first consider the possibility that the condenser coils could be clogged, especially if it’s located on the roof near those nasty dryer-exhaust ducts.
I cleaned my condensers twice each summer to keep them free of lint and breathing well, and that was with the 20-by-20 mesh screens in place to protect them.
For evaporators, change or clean the filters often to keep the unit breathing freely. The standard 30-day filter applies to homes, not Laundromats. I changed my store’s filter every three or four days.
Due to their small filter screens, split-unit evaporators may need to be cleaned every day. It’s a simple, easy job that you can delegate to a trusted employee. Not much harder than cleaning lint from stack dryer screens.
You can reuse your filters a few times if you vacuum them with a wet/dry vacuum. Screens for split units can be brushed clean with a dry paintbrush, vacuumed, or rinsed off in a sink.
Mats in the Southwest will often use evaporative coolers (“swamp coolers”) to effectively cool their stores but the humidity level must be below 30% to get any kind of decent benefit.
They are cheaper to run but they also require maintenance, use water, and don’t always cool as effectively as one would want.
Don’t forget that they add moisture to the air. This also creates a potential mold issue in the cooler itself that can be blown into your mat’s air. So they need to be cleaned often. And remember that humid air also makes it harder for the dryers to dry goods.
If you missed Part 1, you can read it HERE.