New project in the works - adding roof air

[JPete]

John,
When I did some rewiring to my 40AD recently, I ran some cable from the panel at the end of the bed to the One Place as follows: I snaked the wire down the One Place chase and under the shower, thru the existing chase between the shower base and the vanity and drilled a small hole in the bedroom wall ( the wall with the pocket door ) and another in the bed base opposite the one in the bedroom wall and hid the wires with some stick on wiremold where they were exposed in the bedroom. It was an easy job. The return grill in the shower base provided access to snake the wire to the vanity chase.

Hope this helps.

Pete

 

[John Canfield]

Hope this helps

Pete - God bless ya' - I'll consider that first.  I've had the grill off of the shower pan before when I was running Cat5 for the Xantrex from the OnePlace to the power bay.

DW Jane and I drove about 160 miles round trip to pick up the Genie lift this afternoon.  It all went very well until unloading.  I got it about half-way down the ramps and the relatively small wheels got stuck in between the ramp's angle iron cross members.  Not to be defeated, I hooked up the tractor to the Genie with a chain, got Jane in the Genie, put some tension on the chain and told Jane to operate the Genie.  The plan worked extremely well until the Genie didn't want to stop coming down the ramp.  I hollered at Jane to release the joystick, which she did immediately, but the Genie brakes didn't operate instantaneously wow - what excitement.  All I saw was 3500 pounds of Genie lift and Jane coming at me at about 75 mph.

All worked out quite well in the end and no damage was done.

 

[seilerbird]

Back in the mid seventies I was an apprentice electrician and I was given the job of changing about 10,000 4 foot and 8 foot fluorescent tubes at the Charmin Paper Plant in Oxnard California. The warehouse section had 30 foot high ceilings and I was given one of those lifts to do the changing with. It had a limit switch that would not allow me to drive it unless the basket was lowered all the way to the ground. So I would go up to 25 feet, change about 12 tubes, lower it back down, move it ten feet and go up and change a dozen more. That got real old real fast. So the second day I duct taped up the limit switch and so now I could drive it at 25 feet with no problem.

John, if you really want a cheap thrill duct tape up the limit switch and go for a drive. Then come down and change your underwear.

 

[John Canfield]

Tom - 10,000 bulbs- up and down in the lift!? Wow!  My Genie lift will move at 0.5 mph extended so apparently your problem was well noted.  Steering is a little clunky with a rocker switch at the top of the joy stick that doesn't work well with my thumb.

 

[seilerbird]

No, I didn't do all 10k from a lift, just the ones in the warehouse and part of the production area. Most were done off a 6 foot ladder.

 

[geodrake]

I hollered at Jane to release the joystick, which she did immediately, but the Genie brakes didn't operate instantaneously wow - what excitement.

THE VINE JANE, THE VINE

 

[PancakeBill]

made me spit my coffee.

 

[John Canfield]

Making progress.  12/2 with ground is now run from the main breaker panel at the foot of the bed up into the OnePlace area - I used Pete's suggestion to run the wire in the corner of the bed area. .  I used plastic flex conduit for most of the run to protect the wire.  Depending on when our company (due to arrive any minute) leaves, I might be able to get it installed tomorrow.

 

[Missionman]

John,
If I remember correctly you are in North Texas somewhere. I live in Corinth and I would be willing to come by and help you get the unit on top of your coach if you can wait until this weekend.

Michael

 

[Ned]

If you click on the link in John's signature, you can see exactly where he is, to within a few meters

 

[John Canfield]

Michael - that is so kind!  Thank you very, very much for the offer.  Careful planning paid big dividends and scooting the roof unit in place from the Genie lift was easy and simple.  The stamped sheet metal of the roof unit had pretty sharp edges and I sprung a leak on my thumb.  Then I got a pair of gloves  :

Just got the install completed about 4 PM CDT.  Could have been done by 3 PM if I had a circuit breaker on hand.  Had to make the 50 mile round trip into Kerrville to find a Cutler-Hammer 20 amp breaker.  I have used SquareD, Siemens, and GE breakers before, but never a Cutler-Hammer.

First impressions...

- The low profile roof unit is not obtrusive at all

- We now have new sounds and noises, roof noise when you are outside, and blower noise inside the salon.  I think I have become a fan-boy of basement air due to the blower living in a far corner of the coach, however the new noise is perfectly acceptable considering the end result  ;D

- Roof air on high cool is fairly noisy.  It appears we will only need to run the roof air on high cool for a while during the hottest part of the day, low cool otherwise in the afternoon for basement air augmentation and to cool the interior as desired

- As I sit here at the salon table typing this, I am starting to get really cold - the roof unit is blowing cold air on me (the table is 73 degrees.)  How sweet it is

- The cab area is still warm (~ 80 degrees, but cooling) even with the MCD shades lowered.  We won't have even temperature distribution inside unless we run a box fan or two (that's not in the plans though)

- With the roof air blowing cold air very close to the basement air thermostat, that's going to create a little problem with figuring out what temperature to set the basement air thermostat

- Air temperature exiting the roof air (on low cool) is in the 30s, forward vents of the basement air are reading in the 40s, outside air temps are 92 degrees.  The difference might be due to heat gain while the chilled air is making the long roof duct run

- Should have installed roof air three years ago when I first thought about it

- No idea yet how effective roof air will work while we are running down the road in the summer.  I would like to only run the roof air while on the road due to the unit being up and out of the way of road dust and dirt

- The project wasn't too difficult (the major problem being how to get the unit on the roof), but working in the small breaker panel while laying on the floor wasn't my best moment

- It's nice to have a backup AC unit

When time permits, I'll do a full project write-up for our web site.

 

[carson]

Good report, John.  Just remember for every action there is a reaction. Hope you don't freeze to death.

  "Free lunches are rare these days" 

Carson

 

[2dalake]

John, nice job.  So, there was at least one unused space on the bus bar in your service panel for another breaker?  I need to check mine to see if I also have a space.

A comment:  While I do like our Winnebago and think they have many nice features for the money paid, it is unfortunate that one has to add a supplemental AC to their 'flagship' coach.  The manufacturer really should have engineered/spec'd the factory installed unit to cool that coach in hot weather. 

 

[PancakeBill]

Not many coach builders used basement air, Winnebago and Alfa come to mind, Alfa made the mistake of pumping the cool through floor vents, and as we mostly all remember, cold air sinks, hot air rises.  Winnebago at least pushed the cool air up to ceiling vents.  But on real hot days, you loose some cool in the transport, and as John mentions, in dusty conditions the fins etc, are closer to the dust.  Winnebago is going to roof air for the 2011 models. 

Advantages, gaining storage, disadvantage adding weight up high and adding overall height.

 

[John Canfield]

John, nice job.  So, there was at least one unused space on the bus bar in your service panel for another breaker?

Gary - I had three unused breaker positions, but the box is so small fitting two more breakers would be a challenge

Bill - nice summary of advantages/disadvantages of basement vs roof air

 

[afchap]

summary of advantages/disadvantages of basement vs roof air

advantages = quieter operation, no water trickling off the roof 24/7, much easier to clean the cottonwood off the condenser intake (required every two days where we were recently in NW Oklahoma)

Several months ago we were parked beside a Newmar that had basement air/heat pump mounted about midway on the driver side ...think it was a King Aire ??  I would guess it was a 1990 something model...

 

[fred42]

John,

It is only with a small amount of shame that I admit that my RVing started with "Hippie Vans".  I have put roof air on a couple of vans that I built into RVs.  My most recent project was putting a Mach 3 on a 2008 14' Featherlite enclosed aluminum trailer that I converted into a mobile office.  It can also haul a golf cart or Smartcar.  I wanted to pass on what I learned from that experience:

1.  Getting it up there:  I have back issues and spend hours or days designing ramps, tools, hoists, etc instead of just jerking things around like a couple of "normal" men would do in a matter of seconds.  I had a barn and used a cheap Northern Tool hoist.  I had to construct a custom wooden frame to lift it with to avoid bending the unit.  Once on the roof, I unscrewed the frame from around it and removed the frame.  This rig was much lower than a class A, you would need a tall hoist connection as the hoist, chain and unit may take up 4-5 ft. 

2.  The shroud that comes with the unit is plastic garbage.  I installed the $100 MaxAir replacement shroud during installation.

3.  This year, I noticed that the interior ceiling control panel was hanging down a bit.  I assumed it was simply the panel screws, but saw that it was the 4 long threaded bolts that hold the unit on the roof that had come loose.  This allow the unit to shift and bend a couple of the bolts.  If not noticed, I could have lost the unit on the highway.  Now I know what your thinking, "typical hippie installation", but the second man rule I commonly break is to read instructions carefully.  I had installed it exactly as the instructions indicated, compressing the foam seal only as the yellow tabs indicated.  I must admit, if you were not reading the instructions, the intuitive thing to do would be to tighten them much more than I did.  I removed all bolts, straighten a couple of them, and reinstalled, but this time I threaded additional nuts and lock washer on so that I could lock the nut on another nut at the desired tightness.     

hope your project goes well,
fred

 

[Harry B]

Looks like another project nicely completed John.

I believe that the biggest reason for the basement units challenge to really cool the coaches down even though I have no complaints even in FL, is the capacity of the RVP unit vs the size of the coach. The total cooling capacity for the RVP A/C we have is 24000 BTU (2x 12000 BTU). Most 40 ft coaches with 2 roof A/C have 30000 BTU cooling capacity (2x 15000 BTU) installed.....

Now with the added 12500 BTU you exceed the 30000B TU by far, so it should work really well. As you mentioned you now have a spare A/C and you are still able to operate on 30 Amp service with both RVP compressors running. Sounds like the best of both worlds to me.

 

[John Canfield]

Harry - the roof air will have to stay off while we are on 30 amp power, but other than that, we can exist quite well on 30 amp thanks to the basement unit that can run on one or two compressors (and the EMS system )   I'll have to be more diligent about finding campgrounds with 50 amp power when it is hot.

I now have a full afternoon's experience with the roof air running.  Some stats:

Outside air temp - 91 degrees.  Coach parked in full sun.

West facing interior wall temperature (with no awning and full sun exposure) low 80s to high 80s
West facing interior wall temperature (with awning and in the shade) about 78 degrees
East facing interior wall temperature is the mid 70s or the ambient room temp
Salon table temp - 74 degrees
Cockpit dash temp right above the Sony rear view monitor - 75.5 degrees
Cockpit dash temp right behind the windshield - 91 degrees

The roof air has been running since lunchtime on low cool, and the basement air is also on.  The past few days (pre-roof air) our interior would be about 81 or 82 degrees as a maximum for the day, so generally with basement air only we are about ten degrees cooler than ambient air temps.

Now with 37,500 BTU of heat extraction, we are keeping well ahead of heat gain in the coach and that's with the roof air on low cool ;D ;D 

It would be interesting to repeat our Gila Bend, AZ experience of a couple of years ago in June with the roof air.  It was 112 degrees and the best we could cool the coach interior down was about 95 degrees.  That might sound horrible, but we were actually coping quite nicely and weren't miserable (it would have been great to have the interior down to the 80s though.)

 

[mrschwarz]

A couple of more questions:

Did you consider using the block heater circuit for connecting the unit? If so, why did you choose to run a new circuit to the breaker panel? Did you consider installing some form of breakout so in the event you were at a 30-amp site, you could connect the roof unit to a separate 20-amp plug?

How did you get power to it on the roof?