Adding a roof Air Conditioner

BucknJeff · 07-12-2005, 03:15 PM

So..

As any of you that have full body paint 40' diesels with basement air know, on truly hot days, "she just aint got it". We have been down all of the avenues, and find that our system is "functioning as designed". Our plenum is not leaking, and both A/C compressor units are functioning at full capacity. I guess that's Winnebago's way of admitting a poorly conceived and planned heat load calculation. More simply put, there is more than 27000 BTU's of cooling needed to maintain 74 degrees inside the coach. If we are fortunate to park in the right direction, keep the awnings out, all of the window coverings down, don't generate any heat in the coach, and don't open the entry door much, we *might* keep it in the mid 70's when its 90+ outdoors.

This is, in my opinion, foolishness. It is inexcusable that Winnebago refuses to address this issue. No manner of gentle, even forward prodding met with any admission of the issue. Furthermore, Winnebago is missing a revenue opportunity... They could add a roof air unit as an option, and make money! They could also make happy, satisfied, repeat customers. Most of the competition in this class of unit offer a "third roof air unit" as an option. I guess the other manufacturers know the secret, and they just won't tell poor old Winnebago.

So, as we have in so many other cases, we are taking matters into our own hands. We have ordered the new Carrier AIRV LP 15000 BTU 7.5" tall roof air unit. At just under 88lbs installed, its by far the lightest and lowest profile in the industry.

Now on to my question.

Have any of our fellow late model Winnebago owners installed a new roof air unit? Maybe another fantastic vent where you had to cut in the opening? We have found a circuit for the electrical wiring, and will be using the old 120v electric water heater breaker (now unused with the addition of hydronic heat and unlimited hot water last March).

We have spoken to Winnebago customer service, and they advise that the weight is not an issue, even though the owner's manual "infers" that it's not ok. We have found a way to get the wiring through the ceiling, and down past the one-place center, and on back to the circuit breakers safely. The current plan is to locate it in the bath area, just "rearward" of the sliding door between the kitchen and the bath area. This will involve cutting another 14x14 hole in the roof. Really no different than adding another fantastic vent. A job we have already done several times in the past.

Any thoughts, hints, or other constructive comments are greatly appreciated.

BucknJeff · 07-12-2005, 03:15 PM

So..

As any of you that have full body paint 40' diesels with basement air know, on truly hot days, "she just aint got it". We have been down all of the avenues, and find that our system is "functioning as designed". Our plenum is not leaking, and both A/C compressor units are functioning at full capacity. I guess that's Winnebago's way of admitting a poorly conceived and planned heat load calculation. More simply put, there is more than 27000 BTU's of cooling needed to maintain 74 degrees inside the coach. If we are fortunate to park in the right direction, keep the awnings out, all of the window coverings down, don't generate any heat in the coach, and don't open the entry door much, we *might* keep it in the mid 70's when its 90+ outdoors.

This is, in my opinion, foolishness. It is inexcusable that Winnebago refuses to address this issue. No manner of gentle, even forward prodding met with any admission of the issue. Furthermore, Winnebago is missing a revenue opportunity... They could add a roof air unit as an option, and make money! They could also make happy, satisfied, repeat customers. Most of the competition in this class of unit offer a "third roof air unit" as an option. I guess the other manufacturers know the secret, and they just won't tell poor old Winnebago.

So, as we have in so many other cases, we are taking matters into our own hands. We have ordered the new Carrier AIRV LP 15000 BTU 7.5" tall roof air unit. At just under 88lbs installed, its by far the lightest and lowest profile in the industry.

Now on to my question.

Have any of our fellow late model Winnebago owners installed a new roof air unit? Maybe another fantastic vent where you had to cut in the opening? We have found a circuit for the electrical wiring, and will be using the old 120v electric water heater breaker (now unused with the addition of hydronic heat and unlimited hot water last March).

We have spoken to Winnebago customer service, and they advise that the weight is not an issue, even though the owner's manual "infers" that it's not ok. We have found a way to get the wiring through the ceiling, and down past the one-place center, and on back to the circuit breakers safely. The current plan is to locate it in the bath area, just "rearward" of the sliding door between the kitchen and the bath area. This will involve cutting another 14x14 hole in the roof. Really no different than adding another fantastic vent. A job we have already done several times in the past.

Any thoughts, hints, or other constructive comments are greatly appreciated.

troth · 07-13-2005, 03:25 AM

I would call WI and ask them to send you a print showing the roof skeleton brace locations, as well as the sidewall brace locations. I had wanted to add a roof vent exhaust fan in the separate toilet compartment of my Brave. Winnie sent me the layout drawings and it wasn't too difficult to determine where the roof hole should be cut.

BucknJeff · 07-19-2005, 06:32 PM

Well, its in!

I'd LIKE to tell you it was easy. And, really, it wasn't bad. Just tedious.

We ended up removing the fantastic fan from the kitchen area (our micro-hood vents outside, and we use it most of the time anyway). BUT... the interior shroud would have not fit as the enclosure for the sliding door between the kitchen and bath is in the way. So....

The rooftop unit fit just fine. Removed the fantastic fan and the 3,246 screws holding it in place, cleaned off the sealant, and filled in the 3,246 screw holes with dicor. To feed power to the unit, we routed flexible 12/3 up from the basement, under the shower and up to the "One Place" unit. From there, we poped open a small hole in the a/c duct, and ran the wire over to the area inside of the 14x14 opening, again, opening a hole just large enough to get the plenum-rated 12/3 wire in. Bingo!

Now that the upper unit is in, we had to "re-design" the interior shroud mount. We actually reversed the way the shroud mounts, turning it 180 degrees. This made enough room for a great fit. Just a little re-fabricating to get the feed duct into the right place.

Once it was all together, it was thankfully much quieter then we had hoped for.

The Test:

It was about 95 degrees out when we finished. We were in direct sun, and it was 78 in the coach. Fired up the new unit, and in less than an hour, it was 70 degrees. Just for grins, we let it go, and after less than 2 hours, it was 63 degrees. Not bad, 95 and humid outside, 63 inside. After some fiddling, we got the roof unit thermostat set so that it keeps the room about 73, comfortable for us. Of course, we don't need to run it at night, the house a/c does just fine after the sun goes down.

We are VERY HAPPY with this mod. We can finally just LIVE in the coach, without always fearing that we will bake if we open the door too many times, or park in the wrong direction.

If anyone wants to try this, let me know, and I'll be glad to give more specifics.

Cheers!

DonavonP · 07-19-2005, 07:20 PM

Neat job. Any chance for a picture of the outside and inside?
How much higher is the coach?

I have the less expensive, Adventurer, and I think we only have 2,870 screws in the fan.

07-19-2005, 10:29 PM

....get an electric box fan....sounds like you have a problem moving the cold air up into the hot air-andybe you need a down pipe to take the hot air to the basement.....I have noticed thatvery few AC unites have a high wall register for a return. so try a box fan aimed at the ceiling high first then turn it down as the coach cools.....geofkaye

ichn2go · 07-20-2005, 03:08 AM

Sounds like a winner Buck and Jeff. Now that you have become professional Roof A/C installers what is your Rate?????

troth · 07-20-2005, 03:25 AM

BucknJeff, your installation reminds me of one I did on the rear A/C of my old '88 SuperChief. The replacement A/C unit I bought was also Coleman (on sale, a "special"), but not quite the same model as the one that failed in my coach. Anyway, to make a long story short, I quickly learned that I could not mount the new A/C in the normal position because of interference with the bedroom door slide on the ceiling. I ended up turning the complete A/C unit around 180 degrees on the roof and the inside ceiling shroud fit perfectly and the controls were where they should be. Only one or two people ever noticed the rear A/C sitting backwards on the roof, and when questioned, I told them the story...
I never had a problem with the unit, running down the road or parked at camp. True, the evaporator coils were pointing the 'wrong' way, but it never affected its performance. The only other thing I did was to add 1/4" chicken wire screen over the front coil area to provide a little protection from tree limbs.

-"Where there's a will, there's a way..."

LouRobin · 07-20-2005, 07:15 AM

BucknJeff,
Impressive. We are on our second Winnebago basement air motorhome, and have had the same results you stated regarding the inability to keep the unit cool in hot weather.
We were in Key West a few weeks ago, it was in the mid 90's outside and by 3:30 or so the temperature starting climbing. Finally early evening it would level off at about 83 degrees and slowly go down as the evening went on.
AS we travel with animals this is always a concern if we are not in the motorhome. We have the automatic fantastic fans with the thermostats and they were kicking on every afternoon unless we raised their thermostats.

Think I will check into your solution, BUT no way I can do it myself...you all planning a trip to FL?, I think you could make a good living down here with all the Winnebago's in this heat !!!

BucknJeff · 07-20-2005, 06:23 PM

I'll gather some pictures tommorow...

BucknJeff · 07-21-2005, 09:53 AM

So, here are a few shots of the finished project. We are contemplating removing the interior shroud, and interconnecting the new roof top unit into the existing ducting, and adding a few more vent openings to accomodate the extra airflow. Then we would only see a flush mounted intake, rather than the shroud as you can see it now. One project at a time, I guess. I was just glad to get it in, and that it works so well. On the roof, you can see that the CARRIER AIRV LP 15000 BTU (LP = Low Profile, only 7.5" tall!!) is shorter than the DataStorm or the in-motion sat. One other thing I didn't mention before... We routed the wiring safely back to the rear electrical cord compartment. We also left a little extra cord attached. Then we ran an outlet into the same space, and wired that back to the circuit breaker (and ems relay) so that we could choose to run the A/C unit on coach power when we have 50 amp service or are on the generator, or to run the "cord" to the power pedestal at the park in the case of only a 30 amp connection. Some parks, even though they only have 30 amp outlets, also have another circuit of 20 amps, plenty to run the extra A/C without overloading the pedestal. We'll see how it works out.

I have also included a shot of the washer/dryer project. We removed our Splendide unit, and the TV above it. Then we re-worked the cabinet support structure to accomodate the new units. The base is now all solid plywood, and we have re-configured the venting and electrical to allow for the new electric dryer (220V). We have completed the face frame, but are waiting on the new one piece door from the cabinet maker. Hopefully, when its done, you'll never know it was not factory. (well, save for a little better workmanship...)

There is also a shot of the high-efficiency propane-fired Hydronic hot water and heater system. It's not yet commercially available. We have an enclosure that covers the hydronic unit and its hoses, but it is removed in this picture, so you can see the unit. When the cover is in place, it "isolates" the heater unit in it's own "air space". It's air intake and exhaust are on the bottom of the unit.

Photo 1
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Photo 9

troth · 07-21-2005, 11:46 AM

Nice jobs!

Now how did you get those medium sized pics in your avatar and signature?

BucknJeff · 07-21-2005, 12:18 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Now how did you get those medium sized pics in your avatar and signature? </div></BLOCKQUOTE>

I wish I knew... I feel a little odd, what with such big pics, and all. Not sure what to do. We made no changes, it just showed up that way this morning.

I just deleted it, and re-downloaded the avatar, and its still big. Now what?

I feel like a 10 year old kid with size 16 shoes...

UPDATE:

Removed avatar, resized on my server to smaller size, and violla. Still not sure why my profile suddenly decided my avatar should be larger. Maybe its because I talk too much...

DonavonP · 07-21-2005, 04:54 PM

Thanks for the pictures. VERY nice job.

Looks like it's no higher than the DSS dish.

John_Canfield · 07-25-2005, 08:02 AM

Buck n Jeff,

You have to be the modification king!

Did the ceiling part of the new AC present any head-bonking issues?

Since you have added all of the goodies, do you know what your coach weight is?

I also have noticed that on a sunny day with an outside temp of low 90s and with the coach in full sun (Tampa, Fla) and all awnings deployed, the coach will not get below about 78 degrees. I'm okay with that, but now I'm wondering that if we wind up somewhere with temps in the high 90s or low 100s the AC might not cool the coach down below low 80s.

The trick might be to run the coach very cold at night (low 70s) so there is not as much heat to remove in the afternoon.

--John

BucknJeff · 07-25-2005, 03:30 PM

John,

We tried that trick (down to 69 degrees at night), didn't work. That is why we opted to put on the extra unit. It was really quite easy. There are no issues with head banging as it only sticks down 1.75", which is higher than the door divider going into the bath area. (you can see that in the pictures I think).

Weight issues are negligable, The TV and Splendide along with the various cabinetry parts that were removed were far heavier than the washer and dryer combo we installed. The new Carrier air conditioner weighs in at around 88 lbs. The Propane Hydronic unit weighs about 30 pounds less than the original water heater.

We are in the middle of putting in 12volt powered duet cellular blinds in the front window to get rid of that stupid curtian with the draw string. Also adding one at the drivers side window as well. The cellular blinds should also help with insulating the front window area from the heat and cold.

Cheers!

Jeff n Buck

(P.S. HI MS. HUFFMAN!!!)

Rick Buddrus · 07-25-2005, 04:33 PM

Jeff,

You mentioned that you were replacing the front curtain with some 12V blinds. Could you please give a bit more information. The one thing that bothers me about my coach are those dang blinds. Seems like I spend more time making sure they fold up properly than I do disconnecting utilities. Would love to replace them.

Thanks

BucknJeff · 07-25-2005, 06:29 PM

Well, lets see....

The blinds are from Graber, the motors are from a company called Somfy. We have the powered sun shades now, they will be removed, the switches and wires from them will be moved and used to power the two front blinds. We are also removing the two defrost fans in front (since we have never ever turned them on) and we will use the switch and wires from them to power the drivers side shade.

We had to fabricate some wood channels for the shades to ride up and down in, we are getting some ultra leather in the same color as the dash to cover those wood pieces as well as recover the two panels where we removed the fans and sun visors. Not a small undertaking, but it will so worth it! I hate those stupid curtains. (I liked the manual ones much better)

Once we get it done, i'll post some pictures.

Cheers

Rick Buddrus · 07-25-2005, 08:07 PM

Thanks for the description of the job. Will be great to see some pics when you are done.

John_Canfield · 07-26-2005, 01:44 AM

Buck n Jeff (or is it Jeff n Buck)

The AC install will go on my list of possible projects. Thanks for your documentation of the job. I need to have a little more experience with my coach before jumping into something like that. We have only camped three times in the coach unfortunately so I'm still assessing what works well and what needs improvement.

What happens with the condensate drain? I suppose it runs into the gutter and then down the side of the coach. Any issues with that?

Thanks!

--John