6 Attachment(s)
Replacing A Roof Air (Simple Made Complicated)
What should have been a couple hours of work ended up being MUCH longer. My desire to plumb condensation drains through the coach made it a bigger project. The drains weren't really too hard. I ran one through the driver's electrical bay and one just behind the front slide. They are Teed to each air, so they can run either direction. At the same time I ran one drain I had the opportunity to move the elctromagnetic locks I previously installed on the pantry drawers. Not seeing the locks is much nicer.
Attachment 15241
Hoffman didn't make this job any easier. The roof airs were mounted from the roof, not from inside. Inside, they covered the middle ceiling with a blue tinted mirrored finished plexi material. The problem with the mount is that ever after the units were unbolted, there wasn't enough slack in the wiring to unwire the units. No big deal seeing I had already committed to installing drains. Here's the ceiling with the plexi removed. No, those hack cuts weren't mine. I'm not sure why they were there. Anyway, they too were corrected.
Attachment 15237
Dometic air conditioning division is a PITA to work with if you're doing more than a simple replacement. I went from a 13.5K BTU to an unrated "High Capacity" that is assumed to be a 15K BTU unit. I also wanted to go from a 5 button thermostat to the newer 12 button. The 12 button is more feature rich and it supports 3 fan speeds instead of 2. I also wanted one on my existing 15 year old units to share the same newer thermostat.
The first surprise is the air condition is supplied with nothing except the AC unit. No instructions and no mounting bolts. I called about that and they said it's because these are intended to be installed by professionals...really! I needed the bolts because Hoffman mounted them from the roof and their hardware would not work. No big deal, off to the hardware store for mounting bolts. Installing the remote drain kit on the new and older unit was a piece of cake.
I didn't like the limited support that was provided by the original installation, so off to the aluminum shop to get some 14ga aluminum cut and bent. In the old mount there was a piece of wood on 2 of the 4 sides of the opening, but with little support. The new support has L brackets behind the aluminum that supports the roof from the plywood. All 4 sides have support and each is riveted to the next. That's not going anywhere.
Attachment 15235 Attachment 15236
Not getting answers on using CCC 2 control card on my old unit for the newer 12 button thermostat I decided to just order one. The new thermostat supports a 3 speed fan, unlike the old thermostat. No problem the old unit has a 3 speed motor.
Surprise, surprise, the heat pump solenoid works backwards on the old unit. When its not energized it's in heat pump mode. New units are in air conditioning mode when the solenoid is deenergized. No problem I just added a relay to reverse the logic.
Here's the fitment of the panels that would later be covered.
Attachment 15238
The bluish mirrored plexi is gone...yea. I added some hidden vents while reworking the ceiling. I opted for marine vinyl that I padded with sound deadening foam rather than upholstery foam. Wow, big improvement in sound level. Here's the almost done picture. I need to change the color of the grill covers, rework the A/C cover and get some screw covers. The only screws are in the removable A/C access covers and the grills.
Attachment 15239
When it comes time to replace the old unit is really should be an hour's work once the unit is on the roof. After the rally I'll tackle the drain for the rear roof air.Attachment 15240
