Air conditioners

[Snowbirds]

We picked up our 2011 3465 and are giving it a "bumper to bumper' going over. The DW is lining shelves, coordinating throw rugs, packing sheets, blankets etc. I'm more interested in the mechanics of it and I feel that the living room A/C is not as cool as it should be, at least not as cool as I seem to remember the 2955 was. The unit is blowing 42 degree air at the vents. Is this temp close to 'good' or should it be lower?? I also checked the U bolts on the axles and none were 65# but I doubt if I had to turn over 1 or 1 1/2 full turns to reach 65, the shackles were wet bolts which I was glad of but the tires were the infamous GY Marathons, proudly stamped "Made in China".... I guess the GY 614'a will be in my near future....Will appreciate what you guys can tell me about the A/C.

[ole dude]

42 degrees supply air is pretty good, depending on the temp of the air entering the unit. If the entering air was 90 degrees, for instance, it is real good. 20 to 24 degree delta T is pretty much the norm. That can be changed some by changing the speed of the blower, low, med, high. In real high humidity situations a low speed setting on the blower could allow the coil to freeze over--no cooling.

[jimcol]

Snowbirds, Not an A/C expert but seems I remember a previous post by a memeber that was. 20 degrees temp difference outside air to register is considered good. If I was getting 42 degrees at the vents I would start being concerned about the unit freezing up. Remember on your new unit you are cooling a much larger area than the 2955 so it is going to take a lot longer to cool down. Jim

[SlickWillie]

I checked both my ac units just recently. The OEM 15K BTU in the rear has a 23* drop across the evaporator (intake/out to ducts). That is exceptional. The Penguin only had 9* drop; that ain't good. So up on the roof and clean the condenser coils. Ah, much better now. But, I still don't think it works just right. I had a new blower motor installed earlier in the year, and I think it is too high speed. I had actually pulled the cover right after they installed the motor, to check the speed with a mechanical tach, but couldn't access the end of the shaft. Oh well, it cools good in low speed anyway.

[Snowbirds]

[quote]Originally posted by ole dude

42 degrees supply air is pretty good, depending on the temp of the air entering the unit. If the entering air was 90 degrees, for instance, it is real good. 20 to 24 degree delta T is pretty much the norm. That can be changed some by changing the speed of the blower, low, med, high. In real high humidity situations a low speed setting on the blower could allow the coil to freeze over--no cooling.
[/quote

I appreciate your comments. I finally located my handy-dandy Fluke temp meter and put T-1 in the return air and T-2 in a supply air and at 88 degrees outside temp the return temp was 88 and the outlet was 60 after running 2 hrs the return was 79 and outlet was 60 and it had maintained that since. It just seems that it should be cooler than that in the trailer. I should have gone to A/C school and left the Bomb Disposal alone. Thanks guys.

[ole dude]

Some thing you might check---In looking around my a/c unit shortly after purchasing the rig, I pulled the air filter, the took down the inside cover and noticed a few places where I could see daylight. That, of course, was allowing outside air in, which I was having to cool. I taped the places up. Also, I have, as others have, blocked off the return air for the furnace to keep from trying to cool the basement, just remember to unblock before using the furnace.

[SlickWillie]

Another area to check is leakage from the attic. There was a huge hole around the wiring coming into our factory unit. When I had the Penguin installed, the tech didn't even bother to seal the attic from the ac return. I would say 20-24* across the evaporator is exceptional, not the norm. A 15-20* drop is acceptable in the trade.