RV AC Systems need to operate a peak efficiency to keep an RV cool in the summer. Even the best insulated RVs are much more susceptible to outside temperatures than the average house. Combine that with the fact that RVs are generally put in varying elements and conditions (sand / dust, etc), and it's easy to see why maintaining an RV AC at peak efficiency is crucial to glamping comfort!
Our RVIA Certified Friends!
For this RV Maintenance video series, we're partnering up with our friends Todd and Stephanie of the Youtube channel Two Beards and a Babe! www.youtube.com/TwoBeardsandaBabe
Todd is an instructor at the National RV Training Academy (nrvta.com/), where they teach the RV Industry Association Certification courses for both technicians, inspectors, and even those who just want to know more about servicing their own RV!
We're very fortunate to have them on board for this video series!
Items / Tools Required
The tool required are pretty basic and not at all expensive:
- Screw Driver – The AC cover on the roof as well as the inside can generally be removed with a phillips screwdriver.
- Spray Bottle (amzn.to/2yGz0gB) – for light rinsing of the coils.
- EVAP Foam No Rinse (amzn.to/2YnM5uH) – For the Evaporator coil (NSF Registered – for the air we breath)
- AC Foam Cleaner (amzn.to/2YFIbsc) – For condenser coil. Cheaper cleaner for the coils that don't touch the air we breath. Also has a great fin brush in the cap!
- Fin Combs (amzn.to/335MFMh) – To straighten the badly bent fins.
- Metal Duct Tape (amzn.to/2Ypgitp) – Get the good 48mm stuff!
Prior to and after maintenance, it's a good idea to check the delta-T. This is just a fancy term for the difference (delta) in temperature (T) between the air going into the AC and coming out. To check this, use a food thermometer (not a laser thermometer – we want air temps not surface temps). Run the AC for 10-15 minutes to give it time to stabilize, then measure the temperature at the AC intake and at the closest vent. A good delta T is between 11 and 20 degrees depending on your location and the relative humidity. We forgot to do a pre-check, but we read a delta T of 23 after our maintenance!
Before we delve into the details of the maintenance, you'll notice a common theme: Air Flow! Dirt, bugs, bent fins, poorly ducted areas… they all impede air flow and the efficiency of heat transfer. And, that's what it's all about – transferring heat OUT (or in for heat pump mode).
Top Side Maintenance
Top side maintenance is mostly about cleaning and should be done twice a year. One of those times should be in the spring before it starts getting hot! Get rid of anything that's not supposed to be there including, bugs, wasp nests, etc. Also cleaning out the fins of any dirt and debris and straightening out any bent fins.
To clean the evaporator coil, you will want to use this cleaner made for the evap coil: amzn.to/2YnM5uH This cleaner is more expensive, but it's NSF certified (food grade) and is safe to have the air we breath passing over it.
To clean the condenser coil, a less expensive alternative can be used (amzn.to/2YFIbsc). This can also comes with a brush built into the cap that is worth the price of the can alone!
Both coils can be rinsed if needed using a simple spray bottle. It's not rocket science… Clean and straighten and make the unit look as new as possible.
Maintenance on the under-side of the AC (inside the RV) should be done once a season (4 times a year). This is a lot of the same: just cleaning and checking air flow.
First, remove and clean the filters and just generally clean the surrounding parts. The air filters can certainly be cleaned more than 4 times a year if needed.
In addition to general cleaning, you will want to check air flow. Every register side of the AC is different but, in general, you just want to make sure the hot and cold sides are isolated from each other with no bleed-over. This can cause a short-cycle where the cold air goes back into the system, which can freeze the evaporator. Also, related to air flow, check for any obstructions like roof material, etc. If your RV has AC ducting, make sure the path between the AC and the ducting is clean and has no gaps bleeding your freshly cooled air into the roof.
Cleaning and air flow pretty much sums it up. You want good airflow where you're supposed to (coils, vents, etc.), and no airflow where it shouldn't (hot/cold sides, bleeding into roof, etc).
Not only will routine maintenance improve the AC's efficiency and ability to keep you cool in the summer, it can help prevent costly repairs.