June

DOE says to clean or replace the air conditioner's filter every month or two during the cooling season, and that replacing a dirty, clogged filter can lower energy use by 5 to 15 percent. ENERGY STAR's standing rule is to inspect it once a month. A filter can only clean air while the fan is running, and most systems run less than a quarter of the time, so the filter's main job is protecting the coil and blower. Read how a furnace and AC filter works.

Cooling pulls moisture out of the air at the indoor coil; it drips into a pan and out through a condensate line. Drains clog with dirt, mold and debris, and on modern systems an overflow switch then shuts down the compressor, the outdoor fan and the supply fan to prevent water damage, which is why a sudden cooling shutdown on a hot day often points to the drain. The EPA's mold guide says to keep the drip pan clean and the drain line unobstructed. DOE's homeowner fix is a stiff wire through the drain channels.

NOAA: a minimum of 3 days of food, water and medicine, and a storm plan written before the first watch. CPSC's generator rules, written for this season: never run a portable generator inside a home, garage, basement, crawl space or shed, even with doors open; run it outdoors at least 20 feet from the house with the exhaust pointed away from windows, doors and vents; and have working CO alarms with battery backup on every level and outside sleeping areas. Two CPSC rules that do not change with the season: never plug a generator into a wall outlet to power the house, and turn it off and let it cool before refueling.

The EPA's target is indoor relative humidity below 60 percent, ideally 30 to 50. A working air conditioner is the main dehumidifier in most houses; if it cools the house but the air stays clammy, the system may be oversized or the coil may need a look from a technician. Run the bath fan when showering and vent the dryer outside.

Purdue's extension guide puts it plainly: when the air is humid, wood adsorbs moisture and swells; when the air is dry it shrinks, and drawers that moved easily in the factory can stick tightly in service. Paint, varnish and lacquer slow the moisture change but do not prevent it. Wax on drawer runners gets most through the summer; plane only what still binds in the dry season, or you will have a loose drawer in January.