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A desert-proof routine for better airflow, fewer breakdowns, and less swearing
The best time to clean your RV’s air conditioner coils is about three years ago. The second-best time is before they clog up with palo verde flowers and stop working in 104-degree heat.
After four years of procrastinating, we finally climbed onto our motorhome roof and handled it.
We knew better. But life got lifey.
A pandemic and a hundred little distractions pushed this chore further down the list until the front unit finally gave up and froze over.
That’s when we packed a backpack with tools, climbed onto the roof of our too-tall-for-most-bridges motorhome, and got it done.
We sweated, scraped our knuckles, and got a damn good view of the Tucson skyline while we were at it.
Here’s how it went, what helped, and what we’ll do differently next time.
Why You Should Clean Your RV AC Coils Regularly
RV air conditioners are already under a lot of stress, especially in desert climates.
When coils get coated in dust, pollen, or pet hair, airflow drops, efficiency tanks, and the risk of freeze-up or full-blown failure skyrockets.
That means higher power bills, shorter AC lifespan, and a lot more swearing when you realize it’s 95° inside.
If you’ve noticed weak cooling, odd noises, or your unit icing over, this is the first place to look.
Tools We Used (and Why)
We crammed all the tools into a backpack so we wouldn’t have to climb up and down a dozen times:
- Two bottles of Nu-Calgon foaming coil cleaner. Lots of RVers use two different kinds of coil cleaner for the front and back coils, but Nu-Calgon did the job for us just fine.
- A Wolfbox electric blower to blast out dust, dirt, and tree debris before spraying cleaner on the coils.
- A spray bottle filled with water for rinsing (no dragging a hose up there).
- A dish brush for scrubbing and gently straightening coil fins. (Worked better than the overpriced specialty tools.)
- A screwdriver for removing the AC shrouds.
- A towel to lay below the front coils to keep water and excess cleaner from leaking into the ceiling.
How We Cleaned the RV Air Conditioner Coils (Step-by-Step)
- Turn off the breakers for your AC units. You don’t want anything kicking on while you’re up there.
- Pick the right time. We waited until the snowbirds left so we wouldn’t have an audience. Early morning or late evening works best. Avoid direct sun.
- Climb safely. Our ladder is part of the motorhome, but we mounted our Starlink satellite to it years ago, which makes it extra sketchy. Don’t rush. Don’t overreach. Don’t look down.
- Remove the shroud. Use a screwdriver to take off the air conditioner cover and set the screws somewhere safe so they don’t roll off the roof.
- Blow out dry debris. Before spraying anything, we used the Wolfbox blower to clear loose dirt, dust, and tree debris stuck in the coils.
- Spray coil cleaner. Foam it on generously. Let it sit for 5 to 10 minutes.
- Scrub the coils gently to remove dirt, dust, bugs, or whatever else you’ve got going on up in there.
- Rinse with spray bottle. We used water in a bottle instead of dragging up a hose. It took a little longer but worked well.
- Check coil fins. If they’re bent or crushed, a dish brush does the job.
- Reassemble and test. Once everything’s clean and dry, screw the shroud back on and run the unit to check airflow.
Things We Learned
- The two-step coil cleaner method isn’t necessary for regular grime. Nu-Calgon was enough.
- A small electric blower works well and is easier to carry than a shop vac.
- A dish brush is a solid stand-in for those expensive fin combs.
- You don’t need to do this every season, but every couple of years is a smart idea in dusty climates.
- Putting all your tools in a backpack comes in clutch if you don’t want to climb up and down a sketchy motorhome ladder.
Why This Job Is Worth the Hassle
In Arizona, RV air conditioners deal with more than heat. They choke on dust storms, bug corpses, and flower petals from overly dramatic desert trees.
Cleaning the AC coils is a simple way to give your unit a fighting chance and keep yourself from roasting in July.
If you’ve been putting it off, this is your nudge.
We waited four years, which is roughly three and a half too many. Not because we didn’t care, but because it felt like a hassle. Roof work always does.
But the second that unit kicked back on without freezing up, it felt worth it.
This isn’t the kind of task that makes your rig prettier or gets likes on Instagram. But it keeps you from sweating through your sheets in July. And once you’ve done it, you’ll wonder why you waited.
If your AC’s been acting up or you can’t remember the last time you cleaned the coils, go ahead and add it to the list. Right under “check tire pressure” and “where’s that smell coming from.”
Still Here? You Must Be the Human Equivalent of Well-Seasoned Cast Iron Pan.
Most people tap out early like tourists who underestimate Arizona heat. But not you. You’re built different. So why not pull up a camping chair with us on Substack?
