Community Forums

smlranger · 08-23-2014, 05:27 PM

I will swim against the tide here and say after having both, I'd opt for roof AC's. Our 2002 Journey had basement air and it did a much better job of heating than it did cooling. It did OK in all but the hottest weather. If we had kept the coach, I was plotting to install one 13.5 BTU roof AC in the living area roof vent. As far as noise, it was more quiet up front for sure. However, if you are a light sleeper, the noise of the compressors running right under your bed may be an issue. Also, the basement AC is a dust sucker and you will need to change the filter often, especially if you have carpet in the coach.

My current rig has 3 roof AC/heat pumps, all 15K BTU. I believe the noise factor is related to how the manufacturer ducts the units. Ours are not noisy. And at night, you can shut down the bedroom unit and let the mid ship or front AC cool the coach and you basically don't hear a thing.

So roof AC would be my preference. However, I would not reject a coach with basement air if everything else about it was to my liking.

georgetown350 · 08-23-2014, 06:53 PM

If the basement air fails you have no air. If one of the roof top airs
fail you can survive with the other one until repair is done.

wa8yxm · 08-24-2014, 11:24 AM

My choice is roof.. A: Warm air rises so the hottest air is just under the roof, The A/C being there is most effective.

Second: More room in the basement for "Stuff"

That said.... More cool is nice too and easier service is not to be sneered at.

NeilV · 08-24-2014, 11:31 PM

Quote:

Originally Posted by Texbeachbum

If you have a 24,000 btu basement unit and you install 2 15,000 which = 30,000 btu units how does that give you more cooling on the basement unit? From what I understand is the roof units are tied into the same ducts that the basement unit is. You just have 2 units instead of one unit with 2 compressors and coils.

Too much cooling is not that great either as it will excessively chill those it is blowing on and then short cycle leaving humidity in the coach potentially causing mold/mildew issues.

On a 37 foot coach the 24,000 btu basement using may be at its limit especially if its got a dark or dirty roof, dark side body paint/treatments or does not have effective sun shades on the windshield.

Also anything below 78 in the Deep South is not a reasonable expectation when its effectively 118 degrees outside. Most do not pay for electric when they camp and give no consideration to how much electricity is used to cool a coach below 78 degrees in our weather. The Green recommendation for AC in Florida is 80 degrees with some going with 82 to cut energy use just about in half.

Heat pumps that work well up in North Florida are only marginally acceptable once you get near to where I live. There are generally not enough heating days to offset the loss of cooling efficiency you get with a heat pump so straight cool units are best in the Deep South. Yes some unscrupulous salesmen will tell you otherwise but you only have a handful of heating days and then that is usually only for a hour or so in the early morning compared to around 340 cooling days with about a month where you can live with just the windows open during the day.

My straight cool dual compressor unit in my home is 19.9 SEER while a heat pump in that size would have been closer to 15 SEER and cost substantially more money. I spent about 40% less for straight cool and have a unit more appropriate to the climate I live in.

Texbeachbum · 08-26-2014, 10:12 AM

Ok the reason for all my questions. I bought a used MH from a company that sells on consignment.. It belonged to them. They were supposed to check all systems before delivery and make sure they worked. The AC was mot working good. Only had a 10 degree difference. But the guy the showed us everything on delivery just said it was because it was hot and hadn't been on long. I took it home and never did get it to cool right. Now I bought this unit "as is" and to me that means its my problem now. I called and talked to the company and they agreed to fix the AC. I took it in and they have had it for 2 weeks. They were going to just fix the basement ac and let me have it back. I talked to the VP and we have come to a agreement that they will install 2 roof mounted 15,000 btu AC's that tie into my ducts that are there already. They have done about 15 of these. I really thought this was good of them. He said I could just fix the basement ac so it would work but it could go out anytime with the age of the unit. Then it would be my baby. So now I will have 2 new AC s with warranty.

1ciderdog · 08-26-2014, 11:59 AM

Quote:

Originally Posted by Texbeachbum

Ok the reason for all my questions. I bought a used MH from a company that sells on consignment.. It belonged to them. They were supposed to check all systems before delivery and make sure they worked. The AC was mot working good. Only had a 10 degree difference. But the guy the showed us everything on delivery just said it was because it was hot and hadn't been on long. I took it home and never did get it to cool right. Now I bought this unit "as is" and to me that means its my problem now. I called and talked to the company and they agreed to fix the AC. I took it in and they have had it for 2 weeks. They were going to just fix the basement ac and let me have it back. I talked to the VP and we have come to a agreement that they will install 2 roof mounted 15,000 btu AC's that tie into my ducts that are there already. They have done about 15 of these. I really thought this was good of them. He said I could just fix the basement ac so it would work but it could go out anytime with the age of the unit. Then it would be my baby. So now I will have 2 new AC s with warranty.

I do like my basement air but that sounds like a good solution. Where will he put the roof AC's? If he uses existing vents then you lose the ability to use those roof vents for exhausting warm air, cooking heat, odors. The basement air in my RV is marginal when it is really hot outside so I installed a roof AC in an existing roof vent and do miss the abillity to use exhaust fan.

Texbeachbum · 08-26-2014, 02:32 PM

Not sure where they are putting both of them but they told me that I could keep the vent that I have. So I would guess that they will cut new holes for both of them.

Arizona · 08-26-2014, 04:56 PM

I've had two in the basement and several on the roof. We have been in Tucson all summer and the basement a/c works great. It makes a difference with duel Payne windows. I like the home style filters and the overall quiet operation.
The only thing better about the roof style is if it breaks you can kick it off the roof and replace it cheaply. There is no maintenance either. The fan motors and bronze bushing bearings need to be oiled on the basement style and that required sliding it out. It tales about 45 minutes to get it out.
I would want to know where they will wire two roof mounted ones in.

smlranger · 08-26-2014, 08:24 PM

Quote:

Originally Posted by Arizona

I've had two in the basement and several on the roof. We have been in Tucson all summer and the basement a/c works great. It makes a difference with duel Payne windows. I like the home style filters and the overall quiet operation.
The only thing better about the roof style is if it breaks you can kick it off the roof and replace it cheaply. There is no maintenance either. The fan motors and bronze bushing bearings need to be oiled on the basement style and that required sliding it out. It tales about 45 minutes to get it out.
I would want to know where they will wire two roof mounted ones in.

I agree that I would want to know more specifics about how they plan to install these. Everyone that I know of who added a roof AC to a Winnebago with basement air, sacrificed only one roof vent and put in one supplement AC unit. I would also want to confer with Winnebago about the advisability of just cutting two more holes in the roof.

Texbeachbum · 08-26-2014, 08:33 PM

Guess I will find out Thursday. I called them today and they were almost finished. Said it would be ready Wed night or Thursday morning.

NeilV · 08-27-2014, 11:12 AM

Then there is the difference in handling transferring that much weight to the top of the coach. On a 37' 2001 gas coach the chassis is already being pushed pretty much to the limit so shifting that much weight around may require some other suspension mods to deal with sway from being more top heavy.

Sky_Boss · 08-27-2014, 11:15 AM

Quote:

Originally Posted by NeilV

Then there is the difference in handling transferring that much weight to the top of the coach. On a 37' 2001 gas coach the chassis is already being pushed pretty much to the limit so shifting that much weight around may require some other suspension mods to deal with sway from being more top heavy.

X2! When we had a 39' adventurer and considered adding 1 unit on top we opted not to because of both the additional weight moved on top affecting handling and overall weight in general. We already had problems with rear axle weight and adding any to it was not good.

Texbeachbum · 08-27-2014, 03:02 PM

Adding 200 lbs to the top and losing 300 lbs at the bottom. Then making that hole a storage area that will get loaded will make that much difference? So if my 150 lb wife walks from the front of the coach to the rear it will make it drive so bad I will have to stop till she comes back up front.

I think you are picking at straws here myself.

NeilV · 08-27-2014, 07:51 PM

Quote:

Originally Posted by Texbeachbum

Adding 200 lbs to the top and losing 300 lbs at the bottom. Then making that hole a storage area that will get loaded will make that much difference? So if my 150 lb wife walks from the front of the coach to the rear it will make it drive so bad I will have to stop till she comes back up front.

I think you are picking at straws here myself.

She's not riding 12 feet up from the roadway like the a roof top AC unit. 300 lbs below the chassis rails will help stabilize things while 200 above the roof can add a hole lot of destabilization.

I talk to many people who complain about ride stability being so bad that its a major problem (something that I really do not experience to the level these others are having) and the major difference between most of the 2001 35 foot coaches on F53 chassis that I am speaking of is that mine has basement air and the problem coaches have roof air. I have driven some of them and yes driven back to back the roof air units on the same chassis type and size coach do tend to handle differently in tight turns and avoidance maneuvers have a greater tendency to lean.

Get a 12 foot pole, stand it on end and clamp a 2 lb object a foot from the bottom of it and swing it around with the weight close to your hand walking around on a zigzag course while holding it straight up afterwards. Now move the weight to the end of the pole grab it from the far end and do the same thing. There will be a very big difference. Same deal with a motor home and the effect will be more pronounced on a lighter gas chassis than on the heavier diesels.