What monsoon season does to an HVAC system out here.

Dust first

A haboob does not deposit a fine layer of dust on your condenser; it packs the coil. The outdoor unit rejects heat by moving air across a finned coil, and when that coil loads up, head pressure rises, efficiency drops, and the system runs longer and longer for the same result. Left alone, it trips on high pressure — usually on the hottest afternoon of the month, because that is when the margin is thinnest.

The indoor filter loads at the same time. Restricted return airflow drops the evaporator coil below freezing, and a frozen coil stops airflow entirely. If your system is blowing weak, room-temperature air after a dust event, check the filter before you check anything else.

Then humidity, which behaves differently here

For most of the year Mohave County air is dry enough that an air conditioner is doing almost pure sensible cooling. During monsoon, dew points climb and the same equipment is suddenly asked to pull real moisture out of the air.

An oversized system handles this badly. It satisfies the thermostat quickly on temperature, shuts off before it has run long enough to condense much water, and leaves the house cool and clammy. That short-cycling is hard on the compressor and it is the single most common reason a house feels worse in August than it did in June with no equipment fault at all.

The condensate that is produced has to go somewhere. Drain lines that ran dry for nine months grow algae in a week once they are wet. A blocked drain backs up into the pan, trips the float switch and shuts the system down — or, if the float switch has failed, finds the ceiling instead.

Power, and what it does to motors

Monsoon storms bring lightning, blinks and brownouts. A compressor or blower motor that is mid-start when the voltage sags draws locked-rotor current, and the run capacitor takes the abuse. That is why we replace so many capacitors in August — the heat weakens them and the surges finish them.

A hard-start kit and a surge protector at the disconnect are inexpensive relative to a compressor. Worth asking about if you are on a line that blinks.

And water where equipment sits

Ground-mounted condensers in Golden Valley, Mohave Valley and along the river in Topock and Fort Mohave sit in the path of a lot of fast-moving water during a real storm. Silt in the base pan holds moisture against the coil and the cabinet, and a unit sitting in washed-out gravel goes out of level, which stresses the refrigerant lines and the compressor's oil return.

The four things worth doing before it hits

1. Rinse the condenser coil. Power off at the disconnect, garden hose, spray from the inside outward so you push debris back the way it came. Never a pressure washer.
2. Change the filter, then change it again mid-season. Whatever interval the box recommends is a national average, not a Mohave County one.
3. Clear the condensate drain. Find the clean-out, and confirm the float switch actually shuts the system down when lifted.
4. Have the capacitor measured. It is a two-minute test that tells you whether you are going to lose the system in August.

Items 1 through 4 are the substance of a seasonal maintenance visit, which is the cheapest thing on our price list and the one that prevents the most expensive thing on it.

If you are already down

Call (928) 565-6440. Emergency service runs Monday through Saturday and a live person picks up. If the air coming out of your vents smells like a wet basement rather than nothing at all, ask about duct sealing and indoor air quality while we are out — monsoon humidity in a leaky return is how that starts.