What is it about household equipment that makes it decide to break down at the least opportune time?

The washer invariably refuses to spin when you have a week's worth of laundry piled up. The vacuum cleaner craps out when the house is particularly filthy and company is on the way.

The car — don't even get me started about how automobiles seem to know when you just managed to get a little extra cash stashed away and decide it's time for a major part to fail.

The most recent example of this phenomenon in my household?

The electrostatic air cleaner attached to the furnace and air conditioning system has done a marvelous job of removing dust, pollen and other particles from the inside air for the 20 years since we had it installed. When did it decide it was time to quit working? When wildfire smoke began to be a constant presence in the valley, of course.

The air cleaner consists of metal cells with blades that carry an electric charge and attract particles from the air as it flows from the air return into the ductwork. Every couple of months, I pull the cells out, wash off the dirt in the bathtub, let them dry and put them back. No disposable filters to buy, and nice, clean indoor air.

On what turned out to be the last clear night for weeks, we opened up the windows and I took the opportunity to clean the cells and let them dry overnight. But when I reinstalled them the next morning, the unit refused to work.

The local company that services the system came out (after a week, of course, because it's the busy season for air conditioning repair) and delivered the bad news: The air cleaner is burned out and needs to be replaced.

While we wait for an estimate for a new unit, I went off in search of the best disposable filter I could find. Three stores later (the guy helping me at the first stop apologized for his small selection, joking that "you'd think it was smoky outside or something." Funny guy) I had the right size filter with the highest available rating for small particles. And I was only out 20 bucks. Something tells me the new electrostatic unit will cost a bit more than that.

But with the smoke thicker than ever Tuesday, I was glad to be breathing well-filtered air inside my house if nowhere else.

The good news is, the air conditioner is still running like a champ.

For now.

— Reach Editorial Page Editor Gary Nelson at gnelson@mailtribune.com.