A/C Unit

[nuyork212]

Hello all

Well I have the TD parked in the garage and have been testing the A/C unit... Some days are better then others ..
It does take time for the TD to cool down but that is by the numbers

For example:

Saturday readings:

I set the unit at 72 degrees and had the vent open: I would think the drop in Temp would be better or is it me?


11:00 AM- Outside temp- 87 inside: 83
12:00 PM Outside Temp- 91 Inside: 73
12:52 PM Outside Temp 95 Inside: 76
2:05 PM Outside Temp 96 Inside 76

I shut down the unit since I was stepping away for a few hours:

Restart unit:

6:02 PM- Outside temp: 96 Inside 96
8:00 PM- Outside Temp 85 Inside 78
9:00 PM Outside Temp: 77 Inside 73
10:00 PM outside Temp 77 Inside 71

[nuyork212]

Here is a pic of the way the unit was set up. I purchased the TD about 2 weeks ago:

http://i105.photobucket.com/albums/m232 ... 126ed8.jpg

http://i105.photobucket.com/albums/m232 ... 7c9512.jpg


http://i105.photobucket.com/albums/m232 ... 126ed8.jpg
In/Out house coming from underneath unit....

http://i105.photobucket.com/albums/m232 ... 5def10.jpg
I had taken that part off to get to the old vin for a vin check. New vin sticker was place further up front. , that is why u see the the blue duck tape covering the seems.
Just did that for precautionary measures.. that is the return house...per say

I don't know anything about this subject ............so I need a pro. suggestions? Should I leave the vent open?

[Shadow Catcher]

My bet is that you are having an air flow problem. Insufficient air flow will lead to the coils freezing. I solved it by using a bilge blower which I control with a pulse width controller.

[nuyork212]

Thanks
Shadow Catcher

I wish I had the air set up like your where it comes out from the from instead on the bottom... I would have to have a cover built like yours I guess... also seems like 72 degrees is where I should keep it as it does not freeze up like when I have it at 68 degrees...

I have not even attempted to open the box to check out the way the air flow is set up...but don't want to make it worst..lol
bilge blower


So do you leave any windows open while the A/C is on?

[Shadow Catcher]

The trailer is sealed tight with some make up air coming in from the AC unit. I do have the hatch/vent fans on low, there is enough room that it helps keep cool from stratifying at the bottom of the trailer. The bilge blowers come in various sizes and you might be able to find something that will fit, or can be adapted using PVC reducers by going up in size and then back down. One of the factors is that high humidity will cause the coils to freeze up faster, (found that out the hard way).

[aggie79]

I agree with SC - airflow is your issue.

Try removing the "grates" and see if this helps. If you see some improvement, you may want to consider either increasing the area of your supply and return lines - maybe have two hoses for each - or increasing pressure and volume using an inline blower.

[bobhenry]

Take your hand and pinch your nose and clamp your mouth shut tight and jog around the block.

Looks like you are pushing and pulling air in a 4" tube. There is no flow

When I made the delivery duct for exterior mounted A/C unit for the barn all I took off of the unit was the cold/cold air.

The return air is fed with the ambient outside air. There is no problem with freeze up and at 103 I have 65 degree air in the barn.

[Kharn]

Always check for condensate dripping if you think it is not cycling properly. A dripping AC is a happy AC.
If it is not dripping, the coils are frozen into a big block of ice, and you will not get any more cooling until they thaw out, for which you must turn off the unit and wait a few hours.

[nuyork212]

Thanks for the info guys!

[Bogo]

Look at the rectangular duct work the home stores sell. I'd make a duct at least as large as the area of the output vent set. For the return air, I'd make it at least 1.5 times the size of the output duct, with 2X being better. For my home AC, I pipe the output from a window AC unit into the furnace vent system for distribution around the house. I use a 6" round duct between them. It works well in my super insulated home, but have thought I need to go larger with the duct.

When you look at the rectangular duct work, there will be some that are 2"x8" to 4" x 12" or so in size. There will be elbows changing the flow direction. You could run a big flat duct under the unit for return air, then have the cold air go to the interior via a smaller duct run to the side. If needed, it isn't to hard to resize the rectangular duct work, but then you'll need to make your own elbows. Tin snips, a metal edge bender, and pliers are all that is needed.

Looking at your temperatures, it is obvious you are getting cooling, but it look like the airflow isn't enough. One thing that may be happening is the return air is sucking the cold air back and recycling it again.

[KCStudly]

Is the cabin insulated?

[Vedette]

I am sure this subject has been discussed to death here on the Forum.
But I too will be looking to improve our AC when we return from our trip.
The swamp cooler thing just did not work when the temperature was 100 + all night out in the desert!
So we will be looking for the best possible option for our teardrop.
Good Roads
Brian & Sandi