I posted this as a question to the place that I bought the AC unit from but then thought maybe someone here would know the answer.

I purchased a second AC unit last week my son and I will be installing this new unit next weekend and I an making the necessary preparations today 7/5/09.
While reading the installation manual I am seeing that the unit must be mounted at 0 deg nose down when the trailer is level.
But on my unit (mountaineer 345DBQ) the prewired 14X14 vent has about
a 3” angle on the roof from the rear to the front.
This tells me I need to do some leveling of the roof before mounting the new AC.
What material should be used for this and is there a pre built product available.
Or am I reading the instructions wrong.

 

Not that I'm any expert on this subject, but I think I'd look at your existing A/C unit to see how that one's mounted. The 3" roof angle must encompass the entire roof, right? If so, the other unit you have must be off 0* or they have compensated for it to get it at 0*. This would give you some insight as to how to go about it. And if you haven't looked real close at the opening for the new unit, maybe they've already compensated for it when they framed it up.

I'd have to assume that the needed 0* mounting angle is so that water can run out of the unit. I'd also look at that aspect and see if water will drain if it's NOT at 0*. I can't imagine that every application is going to be at exactly 0* for the unit to run correctly.

chaikwa.

 

The other unit is mounted in a more level location.
I don’t think it “must be level” is exactly what they are looking for but it can not be at to much of an angle or as you said the condensate will not drain. The way this thing is made the water comes out of the coils on the side but then runs to the rear. I’m thinking that if I drill a small hole in the pan at the location the water exits the coils I can get away with a small deg off level.
How do you determine the deg off level?

 

I have a cheap dial level thing. It's just a round gauge with a weighted needle that always points up. The dial has 360* all around the outside edge of it. They call it an angle finder I guess, but it's a handy little thing.
http://newark-tools.com/mayes0174-an...e-p-19977.html

I'd get the trailer as level as I could then use the dial level/angle finder thing to determine mounting angle.

I think.



chaikwa.

 

Can you get us some pictures of where you are trying to mount the new unit and of the unit itself.

 

I'll see what i can do this evening

 

Your original post states a 3" angle - - is that what you mean? Or do you mean a 3 degree angle. My main unit over the living area has a 1" slope, the bedroom is flat. They did not try to level the main unit. I have seen sloped shims under factory installs. The shims sat on the factory gasket on the roof and had butyl tape on top of the shims to seal it.

One of the main things in installing the new one is don't overtighten the four bolts down too tight and completely compress the rubber gasket.

 

I did pay particular attention to the instructions on this point. It says to compress the gasket to 60%.

I have a 3 " drop (By drop I mean that from level the nose will be 3” lower than the rear of the AC unit) in the 3' that the AC unit will be covering it will be sitting nose down. Would this be a 1 deg drop or a 3deg or a 30 deg? I’ve looked at this so long that I’m confused.

 

Man it's been a long time but.... you have a 1 in 12 incline. So Tan B = b/c. Tan B = .0834. Angle B = 4deg 45 sec or 4 3/4 deg. Did I get that right?

 

Thanks for helping with the deg of angle


I finally picked up the phone and called Keystone, they told me not to worry about the angle and just mount the AC and turn it on. Now if the AC manufacture says to get it level why would the trailer maker say different? Maybe its because it will not be their bed that has got water dripping on it.

I also called Carrier they said should be level. But that they had no kind of leveling kit.

 

Well after work yesterday I went home and set the new AC up on a table in the workshop. Made a temporary hookup for the electricity set the AC at the same nose down angle as it will be on the trailer and turned it on.
After 3 hours of run time no water was leaking from inside the gasket. but I kept looking and realized that by trimming a small piece of plastic I could let the condensate flow onto the roof ( table in this case ) with no pooling inside the drip pan .
So Saturday my son and I will install this thing as planed.
It turns out that this AC unit is made so that no water would run onto the roof of the trailer under normal conditions. The water was intended to pool under the outside coils were it evaporates. After my little modification it will operate more like a normal RV AC unit, by dripping water onto the roof and running off.