Expecting too much from AC?
We took our 5th wheel out last weekend (Jayco 29.5 BHDS) and the campsite only had 30 amp hookups available, so we could only run 1 AC unit. Unfortunately, that 1 unit could not keep up. On Saturday...
Forum Discussion
2oldman wrote:Old-Biscuit wrote:We've had this discussion a few times and this statement always comes up.
The 20 degree difference is between the A/C Unit Return air temp and the A/C Unit discharge air temp....basically the amount of temp drop across the Evap Coil
MY experience is that my output air is a constant 55 or so degrees. The best my coach can do with that is to stay 20F below ambient.
If the discharge air were only 20F below ambient it would take a very long time to cool the coach. But, this 'fact' has even been said by people claiming to be HVAC techs, which in my case, is just not true. I've even stuck thermometers in there only to be told they were incorrect. So, according to them, my a/c is either 'defective' or magic.
Delta T
“Delta T” is the most common use of the word delta in the HVAC industry, meaning temperature difference. If the temperature before a cooling coil is 75F and the temperature after the cooling coil is 55F, subtract 55F from a 75F to find a delta t of 20F.
Notice the temps are measure before and after the cooling coil...INSIDE Air temp.
Nothing to do with outside air temp
Outside ambient air temps have an affect on 'heat load' but the Delta T is a measurement of A/C performance.
