Roof air vs. Hail stones

[plongson]

A few weeks back, we had a terrible thunderstorm here in the desert that was accompanied by large hail. It beat the snot out of my travel trailer AND the compressor coil on the roof air. The fins were mashed FLAT. I got up there and straightened them out as best as I could (you can imagine how they look) and got pretty good air flow through the coil. The hot side seems to be around 120° (going into the coil) and the cool side is around 100° (coming out of the coil). The inside temps are 70° going in the return and 48° coming out the evap. The ambient is about 85° to 90° this morning. I really don't want to replace the unit or condenser coil if the unit will work.



So the question...



IS that enough of a delta T across the condenser coil (overload and burn up the compressor).



Any suggestions...

 

[scotmartin]

It sounds like you are fine! The fact that you have 22 degrees of Delta T across the evaporator on a 100 degree day, shows that the unit is working quite well. You must have done a pretty good job of straightening those fins.



Scot

 

[Barry]

Next time you are by an RV store, pick-up one of those A/C fin combs. They do a great job of restoring the fins back to their original shape.

 

[Ron Bissett]

looks like its in good shape . Just like a refer ,needs time to cool every thing down ,You could help by shading the Rig or use the water hose to cool the rig down a few degrees. And get that comb washing the fins out helps too. Ron Bissett in Metro Louisville KY

 

[rweis]

Comb set also at A/C shops



Bob Weis

 

[Boondocker]

aw hail

Ditto on that hail damage to the trailer AC!

Thanks for the tip on the fin straightening tool.

I got a little dimpling on some aluminum skirting, but the big fiberglass walls show no signs.

 

[frijole]

HAIL DAMAGE/REPAIR

plongson/all: Go down to Home Depot and pick up a small roll of 1/8 mesh galvanized hardware cloth. Remove the plastic enclosure on the A/C unit and unroll the cloth, cut it to mount to the outside of the return bend header plates on the condenser. Drill 3 or 4 holes on each side, MAKING SURE YOU DON'T PUNCH A HOLE IN A BEND OR TUBE, and pop rivit the material on the face of the condenser, keeping it as tight as practical to the finned surface. Result? No more hail damage to the condensers finned surface. DO NOT try to "wing it" and drill without removing the A/C enclosure, I guarantee a return bend will jump in front of the drill bit! We use 1/4" mesh cloth on commercial A/C units here in NM, saves our machinery from unnecessary damage. Never had much luck with fin combs, they tend to tear the fins. We use a pocket screwdriver, or a small blade screwdriver and just sit down and start sliding up the fins, taking care NOT to tear them or distort them. 20* delta on a condenser is good, 22* on the evap side tells me humidity is low, or fan could stand to move a little more air, BUT, typical of a RV A/C. I did commercial/hi rise/industrial HVAC work in Los Angeles for 30 years, 5 here in NM. Have fun, Ron

 

[plongson]

Frijole... 22* on the evap side tells me humidity is low, or fan could stand to move a little more air, BUT, typical of a RV A/C.



The humidity is typically low here in Las Vegas (Nevada not New Mexico ) The day I ran the tests it was around 20% RH. Would you want to see more delta T or less (22°) at that humidity.



Thanks, Paul...