
The air conditioner in my living room is about 20 years old. It still works, but it’s noisy and inefficient. Once a month, when it’s warm, I drag the 10-foot metal hose to the basement, where it’s replaced by a newer, more efficient model.
The repair was simple. But now that I’m thinking about it, I wonder if it could be done faster.
There’s a simple reason why it’s not: An air conditioner is a sealed unit. A repairman can’t just pop open a door, pull out the dirty coils, clean them, and shove them back in. It’s too dangerous. But with an open system, the repair could be done without letting dust in the air.
Scaling down, the problem can be simplified. The refrigerant, mixed with air, is forced through coils that cool it, then into a metal tube that expands and cools it some more. The expansion valve is the part I need to replace. The valve is screwed into a metal tube, which is connected to the compressor. The compressor pumps the refrigerant through a heat exchanger. The condenser, where the air is blown through hot refrigerant, is the part that gets dirty.