Possible solution(S) for lowering the temperature inside the trailer

[cmikal]

I have a 377RLBH with 2 15k AC units They are installed with the whisper quiet ducting that runs end to end through the trailer. You can't see the AC units from inside the trailer. This is the first year that I will be running the AC in the Summer. Previously, we headed South in the winter and parked the trailer in the Summer, so AC was either not needed or was needed only occasionally or minimally.

This year we will be using the trailer during the hotter months. We are in PA, so it could be worse. Today, it got up to 80 in the shade and maybe 85 or 90 in the Sun. The trailer is parked in full sun. The main living area AC unit will only cool the main living area to 74 or 75 degrees today and runs constantly. The bedroom stays at 72 to 73 degrees (set point is 72). The bedroom AC kicks on occasionally, then turns off at 72 degrees (as it should).

I am aware of many of the cures and fixes for this problem like parking in the shade (not possible for awhile), adding reflectix in the windows (haven't done this yet), adding ceiling vent covers and/or reflectix in the vents and skylights (currently reflective interior covers are installed), installing an RV airflow device in the plenum (I'm not sure if this is possible with a whisper quiet system, so I haven't done it yet), and taping up seams and gaps in the ductwork (doing this now).

The inlet air temperature is 75 degrees (I measured it inside the duct). The outlet temperature inside the duct is around 52 degrees. I think a 20ish degree temperature difference is expected and normal, so I don't think there is an issue with the AC unit functioning properly. Correct me if I'm wrong regarding the 20 degree temperature difference.

My trailer came prewired for a third AC. I'll install it if necessary, but I'm hoping for something else to work before spending the money on a third AC.

Have I missed any tricks or solutions that other people have tried? Has anyone added more ceiling outlets to allow for more air flow? Currently, my main living area has four. The RV has a total of 9 of those round outlets that rotate in the ceiling. I'm wondering if adding 2 more outlets in the living room area would help reduce back pressure and increase air flow or volume. If anyone has tried this, I'd be interested in your results.

What about adding air inlet openings next to the existing openings, or maybe make the existing openings bigger to allow more air to be sucked into the inlet side of the AC unit. Giving the AC unit more of a chance to breathe seems like something worth considering.

Before I sat down to type this, I removed the adjustable louvers in the the 4 living room vents to allow unrestricted airflow out of those openings. Air is now blowing straight down towards the floor. I just checked the temperature. The living room has decreased from 75 degrees to 72 degrees. The AC is still running, but I seem to have gotten a 3 degree drop just by removing 4 louvered vents.

Has anyone cut a hole in the ceiling under the AC unit to basically eliminate the whisper quiet ductwork to allow the AC unit to dump air directly into the living space the way it's done in lower end trailers. Is that asking for trouble or does it improving cooling?

Thoughts on any of the above?

[kirkelli]

Sounds like your AC units are doing the job cooling.. You can only expect about 20 degree cooling from outside temps. You are sitting pretty comfortable at the temps you posted.. Last summer we had a month long heat spell between 105-110... Needless to say,, that was miserable. Make sure to clean your vent filters monthly,,, they clog up with dust and pollen pretty quick.. I keep an extra set on hand and clean them with soap and water.

[Grumpy]

The 20 degree temp drop is good since 15/20 is the standard. Personally I wouldn't be adding any holes in the ceiling until I checked the duct work at the A/C which can be done from the roof. You should be able to remove the shroud and then the box covering the fan to access it.

[cmikal]

Originally Posted by Grumpy

The 20 degree temp drop is good since 15/20 is the standard. Personally I wouldn't be adding any holes in the ceiling until I checked the duct work at the A/C which can be done from the roof. You should be able to remove the shroud and then the box covering the fan to access it.

I've never messed with whisper quiet AC units. I never had a need up until now. I've previously had the plastic shroud off to do some cleaning, but never investigated how everything was bolted to the roof and how to access the opening into the ceiling from above. I guess I'll probably need to do it soon. Summer has just started and we'll be using it a lot this year.

[Randyman69357]

We have the dark full body paint and three air conditioners. I swear we could hang meat in there It gets so cold. I would just go ahead and bite the bullet and add the third air and you’ll be super comfy.

[Learjet]

The 20 degree temp change is from inlet temp to outlet temp. Nothing to do with outside temp. Common misconception.

[cmikal]

Originally Posted by Learjet

The 20 degree temp change is from inlet temp to outlet temp. Nothing to do with outside temp. Common misconception.

That's where I was measuring. Room air temp at the inlet inside the trailer and air temp as it exits the outlet inside the trailer.

[cmikal]

Originally Posted by Randyman69357

We have the dark full body paint and three air conditioners. I swear we could hang meat in there It gets so cold. I would just go ahead and bite the bullet and add the third air and you’ll be super comfy.

I may end up doing that. It's supposed to be about 10 degrees hotter by the end of this week. I'll see what happens between now and then.

[Rustic Eagle]

Originally Posted by cmikal

snip...... adding reflectix in the windows (haven't done this yet),.......snip

I place my Reflectix panels in all the windows that get PM sun..., makes a noticeable difference on my larger slide window.

I only have a single slide, so I added a 'topper' and it made a notable heat reduction 'within' the slide's interior area.

Bob

[Skyline]

I have an 2019 Eagle HT with only one ducted AC unit. I never had a problem with the performance during the Summer except for the first day at a site. I watch the weather report carefully. If it’s expected to be a very warm humid day I turn the AC on early in the morning set as low as it will go. Getting a head start before the high temperature of the day helps a lot. Putting a fan to move some colder air from the bedroom to the living room will also help. I’ve arrived at campsites on 95 degree days after a 3 hour drive, there’s no hope of cooling the unit until the sun goes down. I keep my trailer plugged in at my house. In warm weather everything in the trailer is hot if it’s been sitting with the AC off, everything is hot, floor, walls, cabinets and furniture. I might turn on the AC for a day or two to cool things down before I leave and see if it helps. An extra AC unit would definitely help cool things down but planning also works.

[jetlag]

Originally Posted by Randyman69357

We have the dark full body paint and three air conditioners. I swear we could hang meat in there It gets so cold. I would just go ahead and bite the bullet and add the third air and you’ll be super comfy.

Amen to that. We have the dark body paint and 3 AC's as well, and it works like a charm. Last summer in Hilton Head, we had a 3-4 day stretch of 97-99F days. My buddy, with a similar year/model pinnacle, but no paint and 2 AC's struggled to cool below 85F until the evening. We had ours set at 73F, and they cycled on/off all day. Even my friend noticed the big difference. We were both parked in full sun, so no different variables other than the AC. We didn't order it this way, just found it on the internet. The dealer said he ordered all his Pinnacles and Northpoints with 3 units from the get go. We had no idea it would make such a difference.

[norty1]

One thing is to make sure all your outside hatches are closed and sealed properly.
Any outside air admitted to the units can affect their efficiency and the storage areas are also cooled by the ac's.

[kirkelli]

Originally Posted by norty1

One thing is to make sure all your outside hatches are closed and sealed properly.
Any outside air admitted to the units can affect their efficiency and the storage areas are also cooled by the ac's.

I actually installed lovered vents in the staircase that I can close during summer to avoid loosing that precious cold air into the storage area.. During winter I open them up to assist the return air for heater function

[kirkelli]

Here is a neat read on the topic. https://www.rvzone.com/how-cold-shou...nditioner-get/

[Learjet]

Originally Posted by kirkelli

Here is a neat read on the topic. https://www.rvzone.com/how-cold-shou...nditioner-get/

I stopped reading when I got to "As the cooling air limitation has been restricted to 20 degrees lower than the outside temperature,"

WRONG!

[MarcG]

Do you have to go inside and outside much? Everytime you open the door the cool air will sink and cascade out the door and hot air will get sucked in the top to replace it. You can sit in a lawn chair outside by the door and literally feel the cold air flow by.

[cmikal]

Originally Posted by MarcG

Do you have to go inside and outside much? Everytime you open the door the cool air will sink and cascade out the door and hot air will get sucked in the top to replace it. You can sit in a lawn chair outside by the door and literally feel the cold air flow by.

Originally Posted by MarcG

Do you have to go inside and outside much? Everytime you open the door the cool air will sink and cascade out the door and hot air will get sucked in the top to replace it. You can sit in a lawn chair outside by the door and literally feel the cold air flow by.

On the day that I mentioned in my original post where the temp wouldn't go below the mid-70s, no. The door stayed closed most of the day.

The good news is that I may have found several partial solutions since I first posted. All of the suggestions are free. No cost.

Yesterday, it reached 90 degrees outside. No clouds. I opened the awnings to help block the morning sun that was beating on the entry side of the trailer. I don't know how much this helped because it was primarily morning sun before the day got hot. It had to help a little bit, I would hope.

Next, I lowered the thermostat to 70 degrees first thing in the morning so the interior of the RV had a head start at being cool, vs having the thermostat at 72 or 73 degrees which is where it normally was set. Again, I don't know how much it helped, but I would hope it at least helped delay the time where the air conditioners couldn't cope with the outdoor temperature.

The last thing that I did that I think made the biggest difference was to remove the adjustable louvered vents that are in the living room/dining room ceiling that direct the air in different directions. Now, I have 4 wide open holes pointing straight down out of the ceiling rather than holes that are partially blocked by the louvers.

Yesterday, while it was 90F outside in full sun, the interior got down to 70 to 71 degrees and both AC units occasionally shut off.

Today, its a few degrees cooler outside, and I am going in and out a lot, opening/closing the door, but the interior temp has not gotten above 72.

Removing the vents is fairly easy and straightforward. Mine pop out. I have seen other types that have several screws that are visible from the floor when you look up. Removing the louvers would be my best advice for a first step to get the temperature down, then move on to the other typical suggestions like the ones I mentioned above and/or taping up the gaps around the vents in the ceiling, etc....

[cmikal]

Originally Posted by Learjet

I stopped reading when I got to "As the cooling air limitation has been restricted to 20 degrees lower than the outside temperature,"

WRONG!

??? Please explain "WRONG". Why is that wrong? Sounds like you know the real answer but are holding out and keeping all the "RIGHT" information to yourself.

[Learjet]

Originally Posted by cmikal

??? Please explain "WRONG". Why is that wrong? Sounds like you know the real answer but are holding out and keeping all the "RIGHT" information to yourself.

I guess you didn't read my post above...post # 6?

The standard 20 degree delta has nothing to do with outside air temp. It is inside inlet temp vs. exit temp of the AC...nothing to do with outside air temp.

[cmikal]

Originally Posted by kirkelli

I actually installed lovered vents in the staircase that I can close during summer to avoid loosing that precious cold air into the storage area.. During winter I open them up to assist the return air for heater function

I have the open grids in the stairs that allow free flow of air from the living space into the underbelly. I blocked those off so cold air can't escape into the underbelly. At the time I did it, I didn't have adjustable louvers and din't want to buy them, so I just used solid styrofoam on the inside of the stairs. I had to remove a stair tread to gain access, but it works and has stopped the air flow