Not cooling very well.

GK2018

Well-known member
So I've read a ton of posts on here and was going to see if anyone had anymore suggestions on AC cooling seeing as I'm desperate at this point and we're not even in 110 degree heat yet! We have two rooftop AC's that just constantly run during the day and they only cool the camper 10 degrees cooler than the outside temperature. Our old Mallard M33 bumper pull which was only 5' smaller (37 ft compared to 42 ft) did an outstanding cooling job but this one not even close. I've purchased a portable AC and am soon to purchase a 2nd portable AC and believe it or not the portable AC is 10 times colder than either of the rooftop AC's... I have checked what I can on the ductwork it seems to be attached and sealed, I clean my filters, I'm running 4 big fans to circulate the air, I've tried that homemade shield that helps to redirect the AC through the ductwork and tired other things I'm sure I'm forgetting. I feel like they left out a ton of insulation in the walls because they are hot to the touch unlike our former Mallard. I'm currently at a loss...

Are the AC's under any type of warranty to get them checked out? What about getting insulation within the walls checked out?

It's almost to the point its cooler to be outside than inside this dogon thing... I love this layout but these AC's are really starting to make me miss my old Mallard M33...

The bottom two temperatures are the outside and inside temperature. Ignore the date it's wrong and I've never bothered to set it, that's a picture from today about an hr ago.
3e3ae2e2e93b073eeb3d97624695cbbc.jpg


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danemayer

Well-known member
First, there's the temperature of the air coming out of the A/C vents. Second, there's the amount of cold air coming out the vents. Third, there's the heat load from the sun on windows, walls, ceiling. At times, I can measure air coming out of living room vents at 55 (F). But the airflow is limited and the direct sun is heating the side of the trailer close to 100 (F).

If you have cold air coming out of the vent it sounds like maybe your A/C unit is working and you've done what you can on temp and airflow. You need to work on reducing the heat load.

Some people close off their windows with curtains, or reflective material. That makes it too dark inside for us. We have snap-on outside screening. But that only helps a bit and it does make the interior a little darker.

If I spent more time in hot climates, I would go for window awnings to completely block the sun before it hits the windows.
 

Flick

Well-known member
So I've read a ton of posts on here and was going to see if anyone had anymore suggestions on AC cooling seeing as I'm desperate at this point and we're not even in 110 degree heat yet! We have two rooftop AC's that just constantly run during the day and they only cool the camper 10 degrees cooler than the outside temperature. Our old Mallard M33 bumper pull which was only 5' smaller (37 ft compared to 42 ft) did an outstanding cooling job but this one not even close. I've purchased a portable AC and am soon to purchase a 2nd portable AC and believe it or not the portable AC is 10 times colder than either of the rooftop AC's... I have checked what I can on the ductwork it seems to be attached and sealed, I clean my filters, I'm running 4 big fans to circulate the air, I've tried that homemade shield that helps to redirect the AC through the ductwork and tired other things I'm sure I'm forgetting. I feel like they left out a ton of insulation in the walls because they are hot to the touch unlike our former Mallard. I'm currently at a loss...

Are the AC's under any type of warranty to get them checked out? What about getting insulation within the walls checked out?

It's almost to the point its cooler to be outside than inside this dogon thing... I love this layout but these AC's are really starting to make me miss my old Mallard M33...

The bottom two temperatures are the outside and inside temperature. Ignore the date it's wrong and I've never bothered to set it, that's a picture from today about an hr ago.
3e3ae2e2e93b073eeb3d97624695cbbc.jpg


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To everyone who, in the future is contemplating buying an rv, if it’s over, let’s say 40’, you should seriously consider 3 ac units if you have the choice.
With that being said, if you have 2 ac units, they must be functioning at the top of their game. Do temp checks on the discharge air and be sure they both are cranking out temps in the 50’s and if one is not, have it checked. Even almost new units can have problems.
You can use fans to circulate the room air, but all you’re doing is getting a wind chill. Warm air circulated is still warm.
If your rv cools down at night, run the ac’s wide open and get room temps colder when you can.
Like Dan said, the wall temps can climb to 100 degrees. It’s like trying to cool down an oven.
If you haven’t, it might be worth your time and effort to have someone check your ac units. They should be doing a better job than what your experiencing.
 

GK2018

Well-known member
First, there's the temperature of the air coming out of the A/C vents. Second, there's the amount of cold air coming out the vents. Third, there's the heat load from the sun on windows, walls, ceiling. At times, I can measure air coming out of living room vents at 55 (F). But the airflow is limited and the direct sun is heating the side of the trailer close to 100 (F).

If you have cold air coming out of the vent it sounds like maybe your A/C unit is working and you've done what you can on temp and airflow. You need to work on reducing the heat load.

Some people close off their windows with curtains, or reflective material. That makes it too dark inside for us. We have snap-on outside screening. But that only helps a bit and it does make the interior a little darker.

If I spent more time in hot climates, I would go for window awnings to completely block the sun before it hits the windows.

Our airflow seems partially low in our spare bedroom and that seems to be a common theme with the mid bunks. We do have window tent, black out shades and heavy black out curtains on all of the windows. Measuring our AC temps coming out of both AC's it is outputting a temperature of 64 degrees the portable unit I purchased puts out a temperature of 46 degrees. We dont have any window awnings but that might be something I look into. I've tried to factor in the amount of sun heat (not mathematically but in comparison to our Mallard M33) and they are both drastically different in cooling capabilities which for a higher end 5th wheel seems to be odd. We noticed it wasn't heating as well either this winter but it wasn't necessarily cold enough for me to make a verified determination/comparison to our Mallard which is what began to lead me towards improper insulation plus the walls feeling remarkably hotter. I have also insulated parts of the underbelly for the spare bedroom (theres a post showing the added insulation) which did help quite a bit and I've even went as far as plasti dipping two windows that dont open just to help further insulate. I appreciate the tips and I'm going to look into those window awnings.

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GK2018

Well-known member
To everyone who, in the future is contemplating buying an rv, if it’s over, let’s say 40’, you should seriously consider 3 ac units if you have the choice.
With that being said, if you have 2 ac units, they must be functioning at the top of their game. Do temp checks on the discharge air and be sure they both are cranking out temps in the 50’s and if one is not, have it checked. Even almost new units can have problems.
You can use fans to circulate the room air, but all you’re doing is getting a wind chill. Warm air circulated is still warm.
If your rv cools down at night, run the ac’s wide open and get room temps colder when you can.
Like Dan said, the wall temps can climb to 100 degrees. It’s like trying to cool down an oven.
If you haven’t, it might be worth your time and effort to have someone check your ac units. They should be doing a better job than what your experiencing.

Unfortunately we didn't have a choice of 3 AC units or I would've jumped on that even before now more is usually better but I wouldn't have figured a 5 ft increase in size would've made such a difference in cooling capacity and I'm wondering if heating will be the same way...

The AC output temperature is 64 degrees which is nowhere close to the 50 you referenced so I will get those checked out and hope it's under some type of warranty.

We don't shut off the AC units 24/7 they run all night and day (I'm sure probably isn't good for them, although there has been a couple times I open the windows just so I can give them a rest) and even during the night they just run even if I turn them up from our usual 65 degrees to 75 degrees because the RV never cools down.

I definitely appreciate letting me know about the 50 degree temp output versus our 64 degree output that's quite a difference...

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GK2018

Well-known member
This is 6 hours after the first picture I took, its dropped 2 degrees inside.
7f1cb82acea94cc4a42ea6d3f74ec200.jpg


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TravelTiger

Founding Texas-West Chapter Leaders-Retired
Greg,

I feel your pain, it seems we’ve been “fighting” the heat ever since we bought our Big Country. Most of the heat seems to be coming through the windows.

We tried adding a high quality ceramic window tint, but that didn’t seem to help significantly. We have made our own screens using Solar Screen material cut to size and velcroed to the outside of the windows, for the large windows. That does help the heat transfer quite a bit.

We just had the roof redone with FlexArmor, and that also has helped a little. The best part was they removed the ACs and made sure the plenum was sealed properly before reinstalling them. They seem to put out a little more air and are quieter.

Other mods we have made: 1. Our system claimed to share ductwork, so you could run the bedroom ac to cool the living room and vice versa. Unfortunately it seemed we got very little airflow out the vents. We closed off the duct run in the ceilings to divide the systems into two and this seems to have helped, and closed off the duct run at the very last vents, rather than have the duct continue past the last vent to the rear wall or front of the rv.
2. We replaced all our ceiling vents with ones with “more airflow”. I can’t remember the brand offhand but can look it up if you’re interested. This seemed to help a little, too. You might consider removing the angled vent covers and see if you get more airflow without them.
3. We use a Vornado tower fan to circulate the air. It does a very good job of helping cool the space by circulating the air throughout the room.
4. We applied Dicor CoolCoat to the slide roofs. Again, it may have helped a little. Hard to say since temps are still in the mid to low 90s. Our rig stays comfortable so far.
5. I know you’ve probably read this already, but avoid heat-creating chores during the heat of the day, like cooking or washing/drying clothes, or going in/out the door a lot. Use your awning to help block sun if you can.
6. Keep your return air foam filters clean. I can always tell a difference after they’ve been cleaned.

Using a temp gun aimed at the AC vents, we usually read between 55-65.

Good luck!


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wdk450

Well-known member
If you have a 2020 rig, it is worth a phone call to Heartland Service to see if it can at least be checked for warranty service. There is like a 3 year warranty on the air conditioners, but I don't know about a warranty on the quality of the installation or ductwork - ASK!

Call around and see if you can find any good specialists on RV air conditioning in your area. Ask any fellow RVers or Heartlanders that you know.

Dometic's phone number is: (800) 544-4881
 

GK2018

Well-known member
So thinking about when I mentioned the insulation, maybe I'm wrong on it needing that...? When I cut the dryer vent I noticed it had styrofoam insulation glued to the paneling, I would like to imagine the rest of the coach would be done the same way? Checking something like that might also be near impossible without messing up the paneling and or any styrofoam insulation that I would like to assume is there. The reason I learned towards the insulation lacking is due to the heat and AC systems both being separate in ductwork and functionality yet still both seeming to have issues heating and cooling and also that the interior walls feel much hotter than any camper we've had in the past to include the 79 Wilderness I rebuilt (using rigid foam insulation) therefore leading me to guess that the common denominator would be insulation. But now rethinking this maybe it isn't?

After reading an AC manual I think the AC's are putting out the proper temperature, even though it was 64 degrees coming out of the AC, it was still within the 20 degree cooling margin since the coach was 82 degrees inside. The issue though is 6 hours later the inside temperature only dropped 2 degrees whereas the outside temperature had dropped 6 degrees but once again the AC was putting out it's 20 degree margin on cooling capability.

I had been waiting to post asking for help until I felt I had exhausted enough research on various forums and tried several different things and unfortunately none of them have seemed to work yet.

I do really like Danes idea about the window awnings and potentially a 3rd AC if that's a feasible option for this coach and if so between those two it might fix this issue. I'll have to do some research on the 3rd rooftop AC unless someone has that answer readily available.

I'm currently still in the reevaluation phase on what to do here and have even bought two recliners so I can remove the couch and will have enough room to put in another AC but I'm beginning to second guess this decision as I really feel there is a better option out there that I'm not seeing.

I've debated a mini split AC and was wondering has anybody ever mounted the exterior portion to the roof instead of the bumper? Would there be too much weight for that to work on the roof? Pros/cons on anything about those systems?

I definitely appreciate all the advice and help, I'm pretty handy but at the same time I usually know just enough to get myself in trouble haha.

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GK2018

Well-known member
Greg,

I feel your pain, it seems we’ve been “fighting” the heat ever since we bought our Big Country. Most of the heat seems to be coming through the windows.

We tried adding a high quality ceramic window tint, but that didn’t seem to help significantly. We have made our own screens using Solar Screen material cut to size and velcroed to the outside of the windows, for the large windows. That does help the heat transfer quite a bit.

We just had the roof redone with FlexArmor, and that also has helped a little. The best part was they removed the ACs and made sure the plenum was sealed properly before reinstalling them. They seem to put out a little more air and are quieter.

Other mods we have made: 1. Our system claimed to share ductwork, so you could run the bedroom ac to cool the living room and vice versa. Unfortunately it seemed we got very little airflow out the vents. We closed off the duct run in the ceilings to divide the systems into two and this seems to have helped, and closed off the duct run at the very last vents, rather than have the duct continue past the last vent to the rear wall or front of the rv.
2. We replaced all our ceiling vents with ones with “more airflow”. I can’t remember the brand offhand but can look it up if you’re interested. This seemed to help a little, too. You might consider removing the angled vent covers and see if you get more airflow without them.
3. We use a Vornado tower fan to circulate the air. It does a very good job of helping cool the space by circulating the air throughout the room.
4. We applied Dicor CoolCoat to the slide roofs. Again, it may have helped a little. Hard to say since temps are still in the mid to low 90s. Our rig stays comfortable so far.
5. I know you’ve probably read this already, but avoid heat-creating chores during the heat of the day, like cooking or washing/drying clothes, or going in/out the door a lot. Use your awning to help block sun if you can.
6. Keep your return air foam filters clean. I can always tell a difference after they’ve been cleaned.

Using a temp gun aimed at the AC vents, we usually read between 55-65.

Good luck!


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I haven't tried idea number one you mentioned I'll have to do that and see if it helps. The airflow does in some parts seem to lack more so than in other areas mainly the spare bedroom, I thought about getting one of those duct fans that suck the air through the ductwork and force it back out the vent (can't remember what they call them off hand).

How did you close off and separate those ducts between the two AC's?

I remember you mentioning you did the dicor coolcoat and I've read mixed reviews on it so I wasn't sure that one would work or not so I'd be curious when it heats up what your thoughts on it are.

I really appreciate all the advice and help, I definitely need it!

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GK2018

Well-known member
If you have a 2020 rig, it is worth a phone call to Heartland Service to see if it can at least be checked for warranty service. There is like a 3 year warranty on the air conditioners, but I don't know about a warranty on the quality of the installation or ductwork - ASK!

Call around and see if you can find any good specialists on RV air conditioning in your area. Ask any fellow RVers or Heartlanders that you know.

Dometic's phone number is: (800) 544-4881
My wife actually said the same thing when she got home from work (great minds think alike haha) she said call Heartland Monday and see if they or someone will inspect the AC's and ductwork before we try a whole bunch of other solutions that might not work or will void the warranty. So that's definitely on my list for Monday! She is a 2020 and only a few months old so well within any warranty periods I'd imagine, I'm just not too sure what all "warranty" covers usually I handle any problems myself but this one has got me stumped. I grew up without heat and AC when I was kid and it wasn't fun, I always swore when I grew up so long as I could afford my heating and cooling bill I wouldn't live that way again haha and so far I've been blessed enough to manage that! Wake up in the mornings wearing a snow suit blowing breath and spending days under a shade tree because it was cooler outside than being inside, whew those days... I'm over here reminiscing/having flashbacks

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wdk450

Well-known member
You might want to check out RVServiceReviews.com and the Oklahoma listings. Many of the OKC RV servicers are rated as excellent by the RVers writing the reviews. See:http://rvservicereviews.com/StateList.asp?state=OK

The big performance spec on air conditioning is the difference in temperature between the inlet (warm) air and the outlet (chilled) air. An AC system performing correctly should show at least a 20 - 25 degrees F decrease in temperature. If the incoming air is 100 degrees, the best you can expect is about 75 degrees.
See: https://www.lazydays.com/page/tech-...e, a central AC,65-70 degrees in temperature. "Did You Know" section.
 

Garypowell

Well-known member
I know you said the ductwork was sealed....but in my 3010RE anytime I removed a ceiling light fixture cold air came out.

so I went just past the last outlet in the two runs and constructed my own barrier. This increased the airflow in my rig significantly and cut down the air coming out of a removed light fixture.

I also went to Home Depot and bought circular vents that shut off for the bedroom and bath. At night they are open but during the daytime we close them so all cool air is directed to the living room so it became more livable.
 

dykesj11

Well-known member
We spend a great deal of our time in 90+ and sometimes 100+ weather. Not my favorites but that's where our friends and families live. We have a 2016 BH3575RL, two ACs with common supply and return plenums. We follow the previous recommended actions. This is assuming ACs are operating correctly.
1. run ACs continuously during hot weather to keep the rig as cool as possible even if that means a blanket at night.
2. avoid heat producing activities. When it's hot, cook outside.
3. reflective window covering on the rear window.
4. We do have slide toppers and they made a measurable difference after the first year when we didn't have them.
5. We cut up a pool noodle and placed a section at each end of the supply plenum just beyond the last vents. The plenums go some distance further to no use. Don't know if it really helps but we tried everything.

The biggest improvement however came with this recommendation which was on this forum some years back. (I had thought Dan posted it.)We ordered adjustable vents for the supply side plenum of which there are three in the living room/kitchen, one in the bathroom, and two in the bedroom. During the day, we close the doors to the bedroom, close the vents, open the bathroom door. With this configuration, most of the air, a significant flow, comes from the bathroom vent and the far back vent in LR. At night, we close the bathroom vent, open the bedroom vents and we're good to go. This process has served us well over the years. You may have to mess with what gets closed and opened and the timing depending on rig configuration and which vents on the supply side provide the majority of the air. These systems aren't like home system with supply and demand in mind by zone. Just too small. It won't get us down to 72 on a 100+ degree day but it at least keeps it comfortable and recoverable in the evening.

The vents are Jet Stream #8850 Fully Adjustable Large RV AC Ceiling Vents and they're available at dwincorp.com. Other sizes are available. They also sell air filters for the return side.
 

dykesj11

Well-known member
I know you said the ductwork was sealed....but in my 3010RE anytime I removed a ceiling light fixture cold air came out.

so I went just past the last outlet in the two runs and constructed my own barrier. This increased the airflow in my rig significantly and cut down the air coming out of a removed light fixture.

I also went to Home Depot and bought circular vents that shut off for the bedroom and bath. At night they are open but during the daytime we close them so all cool air is directed to the living room so it became more livable.

Gary - I just saw your more succinct version of what I said after you. The only difference for us was the bathroom vent. Our bathroom vent, with bedroom vents closed, provides a very large airflow. I tried closing it but that airflow didn't seem to transfer to LR vents. Think you just have to play with it. Regardless, this have been the most effective improvement for us.
 

travlingman

Well-known member
I also used pool noodles which helped mine. I cut the noodle to fit at the end of the air run just after the last vents. This made a difference in the flow of air out of the vents. I also got a smaller noodle and cut pieces and placed them in front of the vents in the ducting where it caused the air to have to flow over it.
 

GK2018

Well-known member
I know you said the ductwork was sealed....but in my 3010RE anytime I removed a ceiling light fixture cold air came out.

so I went just past the last outlet in the two runs and constructed my own barrier. This increased the airflow in my rig significantly and cut down the air coming out of a removed light fixture.

I also went to Home Depot and bought circular vents that shut off for the bedroom and bath. At night they are open but during the daytime we close them so all cool air is directed to the living room so it became more livable.
I'll try to pull off a couple of my lights and see if I feel any cold air coming from them, that's not a bad idea. I have a trip over the 4th of July coming up so it might be have to be a week before I can get back on this, I just hope our guests don't sweat while their staying with us. I am fixing to mount and vent this portable AC in the living room tomorrow afternoon though, it seems to have helped drop the temperature quite a few more degrees (went from burning alive yesterday to a nice cool 66 degrees inside while the outside is 87!) . I'll upload pictures of the progress after I finish it up.

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GK2018

Well-known member
We spend a great deal of our time in 90+ and sometimes 100+ weather. Not my favorites but that's where our friends and families live. We have a 2016 BH3575RL, two ACs with common supply and return plenums. We follow the previous recommended actions. This is assuming ACs are operating correctly.
1. run ACs continuously during hot weather to keep the rig as cool as possible even if that means a blanket at night.
2. avoid heat producing activities. When it's hot, cook outside.
3. reflective window covering on the rear window.
4. We do have slide toppers and they made a measurable difference after the first year when we didn't have them.
5. We cut up a pool noodle and placed a section at each end of the supply plenum just beyond the last vents. The plenums go some distance further to no use. Don't know if it really helps but we tried everything.

The biggest improvement however came with this recommendation which was on this forum some years back. (I had thought Dan posted it.)We ordered adjustable vents for the supply side plenum of which there are three in the living room/kitchen, one in the bathroom, and two in the bedroom. During the day, we close the doors to the bedroom, close the vents, open the bathroom door. With this configuration, most of the air, a significant flow, comes from the bathroom vent and the far back vent in LR. At night, we close the bathroom vent, open the bedroom vents and we're good to go. This process has served us well over the years. You may have to mess with what gets closed and opened and the timing depending on rig configuration and which vents on the supply side provide the majority of the air. These systems aren't like home system with supply and demand in mind by zone. Just too small. It won't get us down to 72 on a 100+ degree day but it at least keeps it comfortable and recoverable in the evening.

The vents are Jet Stream #8850 Fully Adjustable Large RV AC Ceiling Vents and they're available at dwincorp.com. Other sizes are available. They also sell air filters for the return side.
I'm thinking those slide toppers might be coming sooner than later. Those might do a fairly good job at keeping the sun off the slides to include protecting it from tree sap and other environmental things.

We bought white spray paint today and I'm going to paint our plastic AC protectors tomorrow since they are currently black and maybe that'll help reduce some heat buildup from the sun. I really liked the black color but ultimately at the end of the day efficiency over looks haha.

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wdk450

Well-known member
If you want to do some internal inspection of your Air Conditioning ductwork, I found this (and many similar) video endocopic systems that work with a smartphone, for minimal cost ($20-$30) on E-Bay. See: https://www.ebay.com/itm/10M-5MP-Wi...983766?hash=item2164cb92d6:g:r~UAAOSwJRldtq~K .If you find problems you should be able to do screen image grabs to send to Heartland Service.

I just may buy one myself, and think that every RV servicer should have one for both AC duct and sewer plumbing issues.
 

Piperflyer

Well-known member
I made the big mistake of not ordering a third 15k air conditioning unit on our RV as an option when we ordered it. We were brand new to RVing and didn't know better. We have slide toppers which help. Presently we are in AZ and looking at temps of up to 110 daily. Both of our 15k air conditioners never shut off all day now and the best we can get the temp to is mid eighty's inside the rig. It still beats being outside. I was thinking of purchasing a window unit that I could put in my back window, as we are staying in this park for the summer months. If not for medical reasons right now there is no way I would be staying in the AZ climate right now.
 
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