(If you live in the arid parts of the country, and use a "swamp cooler", don't even read this section. It's for hot-humid or hot-moderate climates with split-system a/c units.)
That noisy box in your back yard is called a condensing unit. It consists of a compressor, which you can't see, and a condensing coil, which is usually visible as a grille, comprising the sides or top of the unit. The fan inside moves air through this grille, taking the heat away from the just-compressed fluorocarbon gas in the sealed tubing. One problem that develops, especially here in the Midwest, is the accumulation of fluff from cottonwoods, dandelions, and other plants on the outer surface of the grille. This stuff stops the air flow, and the efficiency of your air conditioning goes way down. To put it another way, the cost of being cool goes way up! Getting rid of the fluff is easy! Sometimes, you can just hose it off. A vacuum cleaner and a soft paint brush will do the job, too. Be very gentle with that coil, it's delicate. You may have to do this every few weeks in the summer, and every few days if you live near cottonwood trees.
Of course, if there are shrubs or other obstructions around the condensing unit, you will have a hard time getting at it to clean it. The same obstructions interfere with the air flow, too. Clean that stuff out of there! ========
This is the time of year when wet basement complaints start to crop up. Sometimes, of course, these are actual leaks, but a lot of people mistake condensation for leaking. "Condensation of what?" you say! Well...
When we talk about relative humidity, we mean how much water vapor is in the air relative to how much the air can hold. Cold air can hold less water than warm air. When air from outdoors at, for example, 80 degrees and 80% RH comes in contact with a cold basement wall, the air cools and its RH goes up past 100%. The water vapor that the air can no longer hold has to go somewhere, so it turns back to liquid water, accumulating in droplets on the cold surface. If a large part of your lower wall looks evenly wet, the problem is not a leak, its condensation. If the wall stays wet for more than a day or so, mildew will begin growing in this wetness, creating a grey stain on the wall. The stain won't go away when the water does, so a lot of basements have this grey cloud on the bottom 2 feet or so of wall.
How can you avoid this problem? You have to limit the amount of water vapor in the air of the basement. Dehumidifiers work well, but the best dehumidifier going is central air conditioning. Open up one or two of those basement registers, and let it flow! Yes, I know the basement is already cool, and it seems silly to waste cooling down there, but the basement, and everything you have stored in it, need that drying effect! The absolute last thing you want to do is open windows and blow outdoor air into the basement in an effort to dry it out. That can't possibly work unless the outdoor air is cooler than the coolest part of the basement wall. In my latitude (Detroit) that's 52 degrees F.
Next month, we will go over some of the easier, cheaper ways to deal with actual basement leaks. Till then, Stay Cool!
Matt, at Sherlock Homes
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