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

[cmikal]

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.

They stay closed except when I need to get something.

[EPH 461]

Check out the video below. My son-in-law and I did this and its amazing the difference it made.

https://www.youtube.com/watch?v=fBAUuMoD-ec&t=63s

[cmikal]

Originally Posted by Learjet

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.

I actually did read your post regarding outdoor air temp. I guess you didn't read my response indicating that I was measuring indoor air air temp both at the inlet and outlet.

Here is the exact quote from the article:
"Typically, most of the RV AC units will have a temperature conversion increment of not more than 20 degrees. If your RV is hot like 80 degrees, your AC can drop the temperature down to just 20 degrees, which is 60 degrees maximum and not more than that.".
The sentence says YOUR RV, implying the temperature of the RV, not the outdoor temperature. Later, he mentions outdoor temperature which, to a certified or self-proclaimed expert, might be problematic or imprecise, but to the average person trying to solve a problem it's factually adequate.

I appreciate the conversation, but honestly, I don't think your comments have added anything to the discussion

[norty1]

Originally Posted by Learjet

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.

Another shortfall of a rv ac unit is that the output and intake( return) air are adjacent to each other in a roof top ac. If your home ac was that way it would be very inefficient also.

[cmikal]

Originally Posted by EPH 461

Check out the video below. My son-in-law and I did this and its amazing the difference it made.

I actually did something similar on my previous TT and yes, it worked great. I would recommend it if you have an AC unit that is accessible from inside the camper.

My current AC unit is hidden above the ceiling. I am guessing that doing something similar would work, but the problem is that I think I would need to pull the air conditioner off the roof to gain access to that area. I don't know if it's possible to add the air diversion and isolation baffles without removing the AC unit first.

I'll try if necessary, but right now, I'm trying everything else first.

[Cincinnati Kid]

I have the whisper quiet ducts with prep for 2 a/c's but only have one a/c. In your case, you mention that the bedroom ac cycles on occasionally, brings down the temp, then cycles off..... but the living room a/c continues to run and doesn't get cool enough.
I agree that sealing duct leaks, finding shade, etc are important- but right now you have a situation where one of your a/c's is not running when you need more cooling. It seems that since both a/c's share the same ductwork, what you need to do is adjust the vents (closing the bedroom vents partially) so it doesn't cool off before the living room does. Just keep playing with the thermostats and vents until the 2 units run approximately the same amount of time.
It doesn't make sense to have one a/c off, (half of your cooling power) when the temp is too high.

[Learjet]

Originally Posted by cmikal

I actually did read your post regarding outdoor air temp. I guess you didn't read my response indicating that I was measuring indoor air air temp both at the inlet and outlet.

Here is the exact quote from the article:
"Typically, most of the RV AC units will have a temperature conversion increment of not more than 20 degrees. If your RV is hot like 80 degrees, your AC can drop the temperature down to just 20 degrees, which is 60 degrees maximum and not more than that.".
The sentence says YOUR RV, implying the temperature of the RV, not the outdoor temperature. Later, he mentions outdoor temperature which, to a certified or self-proclaimed expert, might be problematic or imprecise, but to the average person trying to solve a problem it's factually adequate.

I appreciate the conversation, but honestly, I don't think your comments have added anything to the discussion

I wasn't quoting you...but thanks for making me repeat myself and judging my post...just saying...your response was snarky and continues to be. Have a good day.

[Weatherman1]

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.

As Learjet explained the 20 degree temperature difference or what is referred toas Delta T is well within limits of an air conditioner.
It is measured at the air inlet (return air) and air outlets (supply).
A couple of problems with RV air conditioners are air leakage up into the ceiling cavity and poor insulation.
Since there is a lot of glass, that is not really that high in preformance, the air conditioners are always struggling.
I have a 31XL Redhawk that had a vent in the bedroom that I replaced with a 13K BTUH air conditioner, non-ducted.
Funny that it works better than the larger stock, ducted airconditioner.
Since we were in Texas, it was the best thing I ever did.
Just remember you can never have too much air conditioning!
The redundancy helps incase one of the air conditoners fails.
If you have the time take a temperature of the outlet closest to the air conditioner and one at the furthest outlet and note the difference!

Sorry for being a wind bag, but knowledge is powewr. :-)

[Edutron]

Add window AC's. Not practical if you are on the move a lot and only have very short stays here and there, but its a great option for longer stays if you are a snowbird that is if you have to have below normal temps in your coach, but it is all about insulation. You know, they also have water coolers, and there are water fans. I think for full time, window AC's.

[cmikal]

Originally Posted by Learjet

I wasn't quoting you...but thanks for making me repeat myself and judging my post...just saying...your response was snarky and continues to be. Have a good day.

Thank you for noticing. Good day

[cmikal]

Originally Posted by Weatherman1

As Learjet explained the 20 degree temperature difference or what is referred toas Delta T is well within limits of an air conditioner.
It is measured at the air inlet (return air) and air outlets (supply).
A couple of problems with RV air conditioners are air leakage up into the ceiling cavity and poor insulation.
Since there is a lot of glass, that is not really that high in preformance, the air conditioners are always struggling.
I have a 31XL Redhawk that had a vent in the bedroom that I replaced with a 13K BTUH air conditioner, non-ducted.
Funny that it works better than the larger stock, ducted airconditioner.
Since we were in Texas, it was the best thing I ever did.
Just remember you can never have too much air conditioning!
The redundancy helps incase one of the air conditoners fails.
If you have the time take a temperature of the outlet closest to the air conditioner and one at the furthest outlet and note the difference!

Sorry for being a wind bag, but knowledge is powewr. :-)

I'm sure air leakage is a problem, unfortunately, with a ducted system, fixing some of those leaks probably means removing the AC unit. If I were in Texas or another perpetually hot location, I would probably do it. I would probably also install the 3rd ac unit. I'm near Pittsburgh, so I am hoping I can do all the cheap and easy fixes before resorting to expensive or harder stuff. So far, things look promising with cheap and easy.

[rkymntsno]

Add the third AC and be done. In my opinion, the whisper quiets don't cool as well as the "standalone" ACs like the Coleman Mach 8 in my bedroom. But our whisper quiet ducted throughout has trouble cooling the 42' 355mbqs in Texas heat. I won't buy another without three air conditioners.

[Skyline]

I’ve mentioned this before on other posts I have made. Some Flex-Tape or duct tape on the floor (heat) vents might help, it’s easy, cheap and certainly won’t hurt. The coldest air in the trailer is on the floor and the floor ducts are acting as drains. I will try it this Summer.

[Magnolia Tom]

Take a look at the Mods to 377 thread. Removing the black collar from the vents and taping the ducts to prevent leakage into the attic space helps with airflow and you can put the louver vent back on. There’s a duct chase in the loft that supplies air to the bunk room which is not sealed and leaks a lot. All the other things helped a lot but adding the third AC was definitely the answer to hot Texas summers. I would recommend doing all the other minor things first to maximize the results of adding the additional AC.

After say a 5 hour drive in 100+ degree weather, our rig would be 90+ inside when we start setting up. First thing we do is turn on all the ACs. By the time we get done setting up the rig is in the high 70s and within 15-20 minutes it is 72.

Btw, I have one whisper quiet unit and two regular ones that I did the styrofoam thing inside the return grill which eliminates the dump function but the air output is way better

[Cincinnati Kid]

I'm all for finding and sealing leaks in the ducts. I taped all the ceiling vents when we first got out trailer. They hadn't even been connected at the factory, just stuck in a loose hole in the Styrofoam duct.

But the biggest problem that the OP has, it seems to me, is that one of the air conditioners is cycling off when more cooling is still needed. Here's what the OP says- "The bedroom AC kicks on occasionally....."


The living room is too warm, but the bedroom a/c is off! They both feed into the same ducts, so why not run both until the trailer cools down?
They could get a third a/c, but if that one isn't running when you need it either, it's not going to help.

Best to try to see how it works running both a/c's until the hot parts of the trailer cool down.

[Textman]

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

Do have any pictures of what you installed in your staircase? Thank you.

[cmikal]

Originally Posted by Cincinnati Kid

I'm all for finding and sealing leaks in the ducts. I taped all the ceiling vents when we first got out trailer. They hadn't even been connected at the factory, just stuck in a loose hole in the Styrofoam duct.

But the biggest problem that the OP has, it seems to me, is that one of the air conditioners is cycling off when more cooling is still needed. Here's what the OP says- "The bedroom AC kicks on occasionally....."


The living room is too warm, but the bedroom a/c is off! They both feed into the same ducts, so why not run both until the trailer cools down?
They could get a third a/c, but if that one isn't running when you need it either, it's not going to help.

Best to try to see how it works running both a/c's until the hot parts of the trailer cool down.

The front and back AC are on separate thermostats. The main living space is 2 or 3 times the size of the bedroom area, but both ACs are the same size (15k). So, the bedroom gets colder much quicker than the living area. I would need to set the bedroom thermostat below 70 degrees, perhaps waaayyyy below 70 to get each AC to turn off at roughly the same time. I would have a freezing cold bedroom just to obtain an adequately cold living space.

A third AC is an option, but due to cost, it's the last option on the list of possibilities.

The biggest benefit so far was removing the adjustable louvers in the ceiling output vents so airflow restrictions were greatly reduced.

[cmikal]

Originally Posted by Magnolia Tom

Take a look at the Mods to 377 thread. Removing the black collar from the vents and taping the ducts to prevent leakage into the attic space helps with airflow and you can put the louver vent back on. There’s a duct chase in the loft that supplies air to the bunk room which is not sealed and leaks a lot. All the other things helped a lot but adding the third AC was definitely the answer to hot Texas summers. I would recommend doing all the other minor things first to maximize the results of adding the additional AC.

After say a 5 hour drive in 100+ degree weather, our rig would be 90+ inside when we start setting up. First thing we do is turn on all the ACs. By the time we get done setting up the rig is in the high 70s and within 15-20 minutes it is 72.

Btw, I have one whisper quiet unit and two regular ones that I did the styrofoam thing inside the return grill which eliminates the dump function but the air output is way better

I haven't looked at the loft/bunk leakage issue that you mentioned. Never thought of it. (Thank you).

Fortunately, we spend our Summers in the northern states, so the brutal heat is only an issue for short periods of time. I think I can get by with 2 AC units, but will install the third if necessary.

I'll also look at the "Mods to 377" thread. Thank you.

[cmikal]

Originally Posted by Skyline

I’ve mentioned this before on other posts I have made. Some Flex-Tape or duct tape on the floor (heat) vents might help, it’s easy, cheap and certainly won’t hurt. The coldest air in the trailer is on the floor and the floor ducts are acting as drains. I will try it this Summer.

I never thought of that. The only issue is that in the Pittsburgh area during the month of May and sometimes into early June, it can get into the 80s/90s during the day, but the nighttime temperature can drop into the 30s, which means turning on the furnace. It's happened several times already.

I think the 30s are done for the season, so I can seal the furnace ducts now, which should help as we get into the hotter months.

[Cincinnati Kid]

Originally Posted by cmikal

The front and back AC are on separate thermostats. The main living space is 2 or 3 times the size of the bedroom area, but both ACs are the same size (15k). So, the bedroom gets colder much quicker than the living area. I would need to set the bedroom thermostat below 70 degrees, perhaps waaayyyy below 70 to get each AC to turn off at roughly the same time. I would have a freezing cold bedroom just to obtain an adequately cold living space.

A third AC is an option, but due to cost, it's the last option on the list of possibilities.

The biggest benefit so far was removing the adjustable louvers in the ceiling output vents so airflow restrictions were greatly reduced.

They are on separate thermostats, true- but they both blow cold air into the same ductwork.

Try this- Set your living room A/c AND your bedroom a/c to your desired temp. Then when you notice the bedroom reaching the cool temp and shutting off, then start gradually closing your bedroom vents until the bedroom A/c runs longer, helping to cool both the bedroom AND the living room.

You might even find that you're turning your bedroom vents completely off, but experiment!

Another thing to experiment with is the fans. Try leaving the bedroom fan on continuously, so even when the compressor cycles off, if will be drawing in cooler air from the bedroom, and sending it through the ducts to help the living room.

Like I said before, I only have one A/c, and wish I had 2. If I get the second one installed, I will definitely be counting on the bedroom unit to help cool the entire trailer, not just the bedroom, by experimenting with duct vents and fans.