Replaced My Heat Pump

[AmCruiser]

I just replaced the 14 yr old 12000 BTU heat pump that was installed in my B at the factory, with a $99 Haier 5000 BTU window AC from Walmart. The old unit hasn't worked in heat pump mode since we bought it, and in AC mode was only marginal. Last week I tried it for the first time this year and got no cooling at all. I thought about taking it to one of the local RV Dealers to get in serviced but decided that ACs have improved dramatically in 14 years so I probably would be better off with a new one. The old unit about brings my generator to its knees when it starts. Unfortunately, I bought the new one on the spur of the moment before checking to see what the BTU rating was of the original. Had I checked first, I would have gone with a bigger unit.

The hard part was removing the old unit - it weighed a ton and just fit in the cabinet. I salvaged the plastic drip pan base which was plumbed with 2 drain lines terminating under the vehicle. Once I got the old unit out and plugged a couple of bolt holes in the drip pan with silicone, I installed a couple of wood mounting rails for the new unit to sit on. Once in place, I anchored it to the rails with 4 L brackets. The old unit was hard wired. I ran the old power cable to a new outlet box within the cabinet, accessible by removing the louvered weather cover outside the van. I cut a piece if 1 inch thick double foil faced foam sheathing to fit snuggly around the front of the unit, covered with a piece of white faced Masonite, trimmed out with the original oak frame from the old unit.

Time will tell if the 5000 btu unit will be big enough - if not, I can always replace it with a bigger one and use this on in the house. I've run it on both shore power and the genny and it seems to cool the unit quickly enough, but it was only about 80 deg inside at the time.

For heat, I found an old wall mount portable electric heater/fan in the basement that we had bought several years ago. I mounted the quick release bracket on the cabinet door over the passenger seat. We used it Memorial Day weekend down in Camden and it worked pretty good but I need to come up with a means to push the heat down nearer the floor or mount it somewhere lower.
Randy

[markopolo]

Nice neat job

You're in Maine so at least it isn't hot like Florida, Texas, Arizona etc. so the 5000 btu might be fine. I have about the same sized A/C and it was nice to have last summer. I haven't needed a/c yet this year. The nice thing with a 5000 btu unit is that it is no problem at all running it off a standard 15 amp outlet if overnighting at a friend or relatives house etc. It's only about 600 watts so you can run the fridge too on the same 15 amp service with lots of capacity left.

[AmCruiser]

Update -It took a couple of fixes, but I've got the new AC unit working pretty well. The first time I ran it for any length of time, I discovered that it would stop blowing cold air after about 10 minutes. The condenser on the old unit was right up against the louver in the side of the van. On the new unit it is about 7 inches in from the louver so the hot air exiting the condenser was not being blown outside and replaced with cooler air but was being pulled right back through the condenser. After about 10 minute, it was too hot to cool the condenser, hence no more cool coming out of the evaporator.

My first fix was to fabricate some duct work to direct the hot air flow to the louver. I had some double foil faced styrofoam sheathing kicking around so I used that. Its pretty crude and I plan to replace it with a tighter fitting version fabbed from aluminum flashing. The AC compartment has a Dometic refrigerator louver cover with 3 horizontal louver slots. Assuming hot air rises, I directed the duct to the center portion of the two upper louver slots, which would allow the cooler air to enter through the lower slot and the outer ends of the upper slots. It worked well when I first tested it, I let it run for 2 hours and it blew cool air the whole time. The outside air temp was about 75 deg F so I've been waiting for hotter weather to give it a real test.


This week, we have been having a heatwave (for Maine) with the temp hitting 90. On Wednesday, I plugged into the house (you were right Marko - unlike my old unit, I can run this one when plugged in to a 15 amp receptacle) and started the AC. After about 20 minutes it stopped blowing hot air. The louver cover that came with the van when I bought it had been modified by the previous owner who had cut out the louvers and replaced then with plastic mesh. It was pretty ugly so I bought a new one earlier this year and replaced it. Suspecting that the new louver cover didn't have enough open area to get adequate air flow, I put the old cover back on. That did the trick. I ran the unit all day - nothing but cool air coming out. I plan to do some additional mods to the cover to improve it's appearance, but at least its working.

[AmCruiser]

Update 2 - I replaced the temporary Styrofoam duct work with some permanent duct fabricated from aluminum flashing. Its pop-riveted together and held to the back of the condenser with the rear AC housing screws so should hold up better on the road. I wandered around Home Depot looking for ideas to fix the side cover and settled on some aluminum suspended ceiling track and some expanded metal roof gutter covers. A few tin snip cuts, pop-rivets and a coat of paint later and I had a half-way decent looking cover. I finished just in time for a Thursday - Sunday stay at the Birches Campground in Litchfield ME on Cobbosseecontee Lake. It was in the 90's the whole time and the AC worked great. Total project cost was about $130 US ($99 for the AC and the rest for flashing, mesh and ceiling track). Well worth it to stay cool!