About Us

Janet and Paul Stearns

How we added more AC to our RV

Last summer, we learned our lesson about humidity and the effect it has on your AC unit’s cooling performance. After purchasing a dehumidifier, we were comfortable for the rest of last year’s summer camping. But we ran into new challenges as we started our full-time RV lifestyle which began just two days ago!

Day two of full-time RV living – It’s too hot in here, I can’t live like this!

Oh no, what have we done?

Our DIY AC project happened quickly as we were sitting in the RV as it climbed from 70 degrees in the early morning to a sweltering 88 degrees by 2pm. Our rooftop AC unit hadn’t had a break all day and just couldn’t keep up with the climbing temperatures.

As a side note, we were able to track the temperature in the RV throughout the day thanks to our Canary All-in-One Indoor 1080p HD Security Camera. See “The Results” at the end of this article for a screenshot of the type of reporting the Canary provides.

Note to self, our next RV will have two AC units.

I really just looked at Paul and said: “let’s go buy a portable AC right now” and off we went. Decisions were made live and on-the-spot considering the options in stock at a local store.

Portable AC units are made for homes and small apartments and are not specifically designed for RVs, especially when it comes to fit. Essentially, “portable” still = huge and cumbersome. Some promising products are coming out of Kickstarters, but not in time for my need TODAY or I’m gonna melt! To make the best of this, we established the following criteria.


  • Must have the smallest possible footprint.
  • Does not need to be all-powerful for the space we need to cool. It will be an “assistant” to our rooftop AC unit, not a replacement.
  • Should be rated for the smallest square footage we can find (turned out to be 200 sq ft). A 30′ RV is not huge on square footage so the smallet rated unit should be fine.
  • Can NOT be an “evaporative” AC type. We do not need more humidity!


The Winner

Best Choice Products 3-in-1 10,000 BTU 2-Speed Portable Air Conditioner Cooling Fan Dehumidifier

How we installed an additional AC unit in our RV

Now that we bought it, how do we make it work in the RV without tripping over it or its giant exhaust tube?

We really had two options.

The bedroom was the worst spot for retaining heat which made sleeping uncomfortable. We initially considered placing this unit as close to the bedroom as possible for maximum effect. This meant it would be on the floor by the bed and we would need to walk around it and move it out of the way continuously throughout the day depending on if we wanted to get into the bedroom or into the kitchen pantry cabinets. The exhaust tube would also have to vent out the small window next to one side of the bead, at Paul’s head. This was not ideal. Being cool in exchange for sleeping with a giant tube next to your head is not a trade-off that comes out advantageous for anyone. We needed to select another spot.

We settled on placing the unit upfront between the driver and passenger seat. But, there was a hump in the road with this plan, specifically, the hump between the seats. It was not flat enough to keep the AC steady and not have it tip over. The first night, we tried balancing it by placing objects in front of the hump: a cooking pot, a laptop stand, and finally, a plastic toolbox did the trick.

The next day, Paul went back to the store for supplies and built an interesting table that would allow the unit to sit steady and level while taking into account its awkward position over the hump. He purchased 4 short table legs that came with their own hardware and did not need to be modified at all. He also had some plywood cut for the table top allowing enough room for the AC unit while taking into account the odd placement of the table legs, and taking advantage of the hump for some extra table support. Lastly, he added a small strip of wood to the front of the table because this AC unit has wheels and we did not want it to go rolling off.

Here is the final result:

Managing the external venting

We planned to have the tube extend over the driver’s seat and out the window. No big deal to take up space on the seat, we don’t normally use this seat when we’re parked. The challenge was to adjust the window insert that was included from a house style square-corner window shape to an RV style curved window shape. The first night we didn’t care and velcroed the vent inside its mounting attachment to the wall just above and just below the window. Then we closed the glass window against the insert and shoved all the foam insulation that came with it around the spots that needed sealing.

Back at the store again, Paul purchased some plastic foam board that was easy to cut but still strong enough to hold its shape inside the window frame. After cutting the hole for the vent, he attached the vent inside its mounting attachment to the foam board and mounted everything into the window frame by simply inserting it into the frame where the glass window would normally go and then closing the glass window up against it.

Managing the power draw

On the first night after we got it set sturdy on the toolbox and hacked the vent to the window, we plugged it into an outlet inside the coach, turned it on, and give a big sigh of relief. Cool at last! About 30 minutes later all the power in the coach went out.

To solve this, Paul cut a very small hole in the plastic foam board and snaked an extension cord through the opening. We plugged our new AC unit into one of the 15 amp sockets outside on the shore power pole.

The Results

The results were amazing! Even through the hottest part of the day with temperatures in excess of 98 degrees and humidity through the roof, our new AC made a great assistant to our roof AC and kept temperatures consistent throughout the day. From the moment we plugged it in through the heat of the day, temperatures never went beyond 73 degrees inside the RV. That’s a huge difference from 88 degrees the day before. I’d call that a big win!



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