Wednesday, May 29, 2013

Installing a RV Refrigerator into a Cabin
Scott Symmes11:36 PM

With the summer fast approaching, the quest for cold beers and the ability to store food for longer periods would definitely keep the family happy and increase the moral. Therefore, the propane RV refrigerator project shot up to the top of the list.

Prior to the propane fridge, we had a 12 volt Mobicool thermoelectric cooler. On hardware store shelf, it looked ideal for my humble 12 volt solar system and didn't seem to draw a lot of amps. It cost around $100 dollars and was easy to move. But, the downside, it had to run all the time, 24 hours a day! In about a day, it would drain the four 6 volt golf car batteries down to dangerous levels. I'd have to run the generator to charge the batteries back up. It was a waste of fuel and time.  We ended up disconnecting it and use it as cooler with blocks of ice.

The next plan was a small refrigerator that would be used in a dorm room or under a bar, It ran only on AC current, but, we estimated it needed about 175 watts to run on the lowest setting. It worked without problems in the summer months and it was exciting to see it running full-time off my solar panels system. But, as the sun got lower in the sky, I noticed it started to draw more current and drain the batteries. Luckily the AC inverter had a low power setting and shut off the power before the batteries were damaged.

Wall modified for RV fridge 
One day, a good neighbour dropped off an old Dometic 12 Volt or propane refrigerator. He had upgraded to a bigger model in his cabin and wasn't using the smaller one. What a treat! Since I was new to propane appliances  I was a little leery about bringing it inside. So for the first year, it was out on the back deck working. My spouse made a few subtle comments about it looking a little junky for the neighbour. So, I decided to bring it indoors.

The only problem with the smaller style of RV refrigerators is that it needs to be inserted into a cabinet. The plan was to install it into a nifty wall/pantry unit, but, there just wasn't enough time to build it. I suggested that we go to IKEA and check out the "As Is" section for any cabinets or wall units that were big enough. Ended up finding a pantry unit with a couple of dents, but the price was right and was perfect for the space.

Before any building, I went online a found a Dometic Installation and Operation Manual. An excellent guide with diagrams for 5 different Dometic models. For example, on page 16, there is a Technical Data chart giving overall and recess dimensions, capacity, weight, electrical data (watts) and LP gas data. very handy! 

RV refrigerator can sit in a cabinet, but the chamber behind the cooling
Chamber covered with flashing
elements had to be made from non-combustible material. Went to my hardware store picked up some wall flashing and furnace ducting.
The plan was to make a box in a box approach. That way, if I did need to service the RV refrigerator, it could simple slide out of the chamber. The installation manual had all the measurements and I made a simple box out of plywood,
After assembling the IKEA pantry unit, I measured for the height of the plywood box and adjusted the shelf it was to sit on. Added a few more boards to the shelf for extra strength.
After the RV fridge was hoisted up and on to the pantry shelf, I went around the back and did some more measurements for a ventilation chamber for the wall.
Since the cabin wall behind the fridge was not insulated yet, it was easy to trim the boards and build a frame. It looked like a window frame, accept there was no hole for a window. Once the lower, upper vents, hole for propane hose and exhaust for the flue were cut, the unit would slide back and screwed into place.

For the exhaust flue, a 4" dryer vent was fastened to the flue with pipe clamps. A larger 6" hole was cut and flashed with furnace duct metal. To keep out drafts around the 4" vent, a special high temp caulking used for wood stoves was pumped into the cavities. Spray foam was used in other spaces where there was no contact with heat.

4" Dryer vent through wall

View from the exterior

The IKEA pantry is pushed to the wall

Since the  propane RV refrigerator project was completed, it been wonderful. We use it all year and it is really efficient on propane gas. A standard BBQ tank will last 2 months. My spouse is happy and in turn, everyone is happy.