RV Rooftop AC Update

[John T]

In a previous post I questioned the discharge air temperature of my 12 year old RV rooftop AC unit which was around 61 Degrees. YES the coils and filters were all clean and the compressor and fan motor both started and ran fine n smooth. YES, there was an informative discussion of DELTA T. NO, those units DO NOT have refrigerant service ports.

I bit the bullet and installed a new replacement same BTU AC

Under similar ambient temperature and humidity conditions THE NEW AC DISCHARGE AIR TEMPERATURE IS 53.7 and she pumps out a lot more condensation (like raining n out there lol) Wooooo Hooooo

Now I'm a COOL n Happy Camper

Thanks to all who replied

John T

 

[M-MAN]

Glad you're nice and cool John. Your old unit is a sealed system just like a refrigerator or room air conditioner. You use a line tap port to service.

 

[John T]

Yep I used to have a buddy that could install saddle line taps on the sealed RV rooftop AC's, but he up n died on me and no one in this area does that anymore grrrrrrrrrrr

John T

 

[300jk]

John I missed your original post. Wish I would have seen it. Our family are campers. Travel trailer. We are actually camping this weekend and next at a campground. We recently had to take our camper in because of a faulty thermostat for the heat/air. Just fired up the ac a bit ago and no cold air. Started getting a little nervous. 90 and humid today ! Come to find out I didn't have something set right. Ours is controlled by a remote. Figured it out and all is good ! Will be nice and cool for my afternoon nap !

 

[JMOR]

(quoted from post at 08:23:21 06/30/18) In a previous post I questioned the discharge air temperature of my 12 year old RV rooftop AC unit which was around 61 Degrees. YES the coils and filters were all clean and the compressor and fan motor both started and ran fine n smooth. YES, there was an informative discussion of DELTA T. NO, those units DO NOT have refrigerant service ports.

I bit the bullet and installed a new replacement same BTU AC

Under similar ambient temperature and humidity conditions THE NEW AC DISCHARGE AIR TEMPERATURE IS 53.7 and she pumps out a lot more condensation (like raining n out there lol) Wooooo Hooooo

Now I'm a COOL n Happy Camper

Thanks to all who replied

John T

or future reference, while you have a properly working unit, measure return air temp and outlet temp (out-in)= ? Write it down. Excepting humidity, the outlet will be a near offset from the return, i.e., inlet goes up, outlet goes up, inlet goes down, outlet goes down.

 

[rustyfarmall]

Back in the '70s, when the refrigerant was still R12, we expected the air temperature from the dash vents to be right at 40 degrees. If the air temp was much higher than 40, the system needed work. This new R134 stuff is not capable of doing that, and I can notice the difference.

 

[guido]

Hello John T,

I could send you some left over saddles. Then you you would have to buy the gauges and the refrigerant and the soldering gizmos. Tap a line fitting like a water supply for a fridge? Not a good fix ever. On second thought, a new unit is much cheaper!

Guido.

 

[sotxbill]

cant make up my mind is the saddle self piercing taps are good or bad. I have used them, but others swear they will eventually leak. My late fil could partially open the crimp end, and solder in a fitting, then open the crimp fully so the fitting would work. He was great at most everything.

the "in" vs "out" temp along with air speed setting will usually tell you how the unit is performing. Faster air speed is best for starting out.. Slower air speed will cool more, and dehumidify more as it spends more time across the coils and can transfer more heat,,, is better after the initial cool down.


However the unit can only remove so much heat per minute. And if more heat is coming in the rv than the unit can remove, your goning to be hot. Also a heat soaked rv where the walls and interior have be hot for a long time, will also take more cooling longer, than an rv that already cooled down.

 

[John T]

Yep in years past I had some line tapped and refrigerant added which helped for a while BUT later they leaked, then I was out that expense grrrrrrrrrrrrrrrr The new one should last say at least 10 years or even more, likely longer then I will live or RV, so I just went with the new unit and sure am glad since it, unlike the old one, IS COOLING VERY WELL.

John T

 

[guido]

Hello John T,

Like I said mix 50's is the good temp range. Probably has 410a refrigerant. I hope you stay kool.....

Guido.

 

[DoubleO7]

(quoted from post at 22:49:51 06/30/18) Yep in years past I had some line tapped and refrigerant added which helped for a while BUT later they leaked, then I was out that expense grrrrrrrrrrrrrrrr The new one should last say at least 10 years or even more, likely longer then I will live or RV, so I just went with the new unit and sure am glad since it, unlike the old one, IS COOLING VERY WELL.

John T

We have a Dometic rooftop a/c in our 12 year old trailer.
That thing cools well but is very loud. So loud we no use a window unit instead.
Is your replacement so loud you can hardly talk to each other?

 

[Motorcraftman]

OHH Ya, They will Leak... Anything that isn't Hermetically Sealed... Like a Ref, Will/..Larry...