Whether you have an older air conditioner or a newer, high-efficiency system,
maintenance is critical. Older units need all the help they can get and high-efficiency models won't deliver all that high-dollar
efficiency without routine care. The primary culprit is dirt and debris, which clogs coils and taxes equipment, but even something as simple
as an out-of-level condenser unit can reduce efficiency and burn bearings. Here, more than most places, maintenance pays.
And all it takes is about an hour a season. In most cases, you won't even need to buy tools and materials.
Most of the work you'll be doing will be outdoors, on the condenser unit.
To eliminate any chance of an electrical hazard, begin by opening the unit's electrical disconnect panel and pulling the disconnect
block from its slot (Fig. 1). Most such panels come with a reversible on/off block. Just flip the block over, so that off
reads correctly, and return it to its slot.
In order for the condenser fan to do its job, its louvered panel needs to
be fairly open. The tradeoff is that plenty of leaves and debris get into the housing when the fan's not running. To remove
the debris from this compartment, undo the screws at the top of the unit and tip the panel upward. Then, lift out any leaves,
twigs and debris you find in the coil enclosure (Fig. 2).
To clean the outside of the coil, undo the screws from one of the side panels,
or from all three sides, if the design of your air conditioner makes that more convenient. Then, use a soft-bristle paintbrush
to sweep the fin tubes clean (Fig. 3). Always brush vertically, in line with the fins. Because the fan pulls air through these
fins, you can expect to find a blanket of dust and lint clinging to the fins, which can really reduce efficiency.
The condenser coil's aluminum fins are paper thin and very delicate, enough
so that you may find several areas where the fins are smashed together. Virtually anything can damage them. Of course, smashed
fins won't remove much heat, so it's a good idea to straighten them whenever possible. For a minor crush, you can use a toothpick,
but for professional results, nothing beats a fin-tube comb. They're only sold by HVAC suppliers, but they're inexpensive
and will last a lifetime. We paid $11 for a 6-comb set, with each plastic comb sized to fit two fin spacings. Our kit, called
Super Comb Model T-400, covers spacings from eight to 20 fins per inch and was made by Wagner Products Corp., 5190 N.W. 165
St., Miami, FL 33014. Be sure to match the tool to the spacing. Then carefully insert the teeth and comb through the damaged
area (Fig. 4). You'll be impressed by the result.
After you've reinstalled all the panels, check the condenser unit for level.
Condensers are often set on backfilled soil, which tends to drop like a rock, especially through the first few seasons. If
the condenser has settled out of level, the strain can wear out bearings and reduce efficiency by as much as 10%. Check for
level, in both directions (Fig. 5), and if needed, pry up one end of the support pad and add soil or gravel until the pad
is level. Slate shims can also be used for minor adjustments.
And, finally, one of the most frequent air conditioner maintenance problems
is a clogged condensate line. The culprit is a bacterial slime that grows in condensed water. To keep this line flowing freely,
pour a 1:9 mixture of household bleach and water through the line every month or so during cooling season. Just pull the hose
from its A-frame fitting and flush the line, all the way back to the floor drain (Fig. 6).–M.H.
