I suggest you use 2 accurate thermometers.
Ac unit temperature drop attic duct.
Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts.
The temperature your ac puts out is relative to the temperature you set on your thermostat.
You should expect a 15 to 20 degree temperature differential from the air temp going in and the air temp coming out after the unit has been running a period of time.
To reset the switch you ll need to climb up into.
So why put an hvac system up in the attic at all.
There too unless the supply duct is long uninsulated running in a hot space such as an attic the air temperature at the supply register should be around 55 degrees.
Attic hvac systems save space.
Summer hasn t even arrived he notes in a post at gba s q a forum and when the temperature outside climbs to more than 95 f the temperature in the attic tops 120 f.
2009 ashrae hof chapter 4 equation 48 pg 4 21 this calculator estimates the temperature drop or rise of air flowing in a duct.
Ted also has inherited a powered attic ventilator.
If the temperature in your area rarely gets that hot wait until as hot a day as possible to test.
Put one into a return duct closest to the unit as possible.
An attic can get up to about 130 f in the summer and the conditioned air entering the ducts is about 55 f or so.
Place the thermometer on a vent and leave it in.
Instructions input information may generally be be obtained from design documents or field measurements.
That has kept the ventilator working but ted surmises the high temperatures are reducing the efficiency of his air conditioning equipment.
The system should be blowing air that is noticeably cooler than the building s air.
Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal.
In addition to making the unit hard to get to for service high attic heat can trigger the high pressure limit switch turning your condenser off.
Put another into a supply duct as close to the unit as possible.
So even though there s no single ideal temperature you do want a 16 22 f difference from the supply air and return air.
Then allow the ac unit to run at least 15 minutes.
The result is that air your furnace or ac has already treated is losing energy back into the attic.
Well mainly it s a way to save space.
As long as the building has not reached its thermostat s set point.
It also means that the air in those ducts is continually exposed to the ambient temperature in the attic.
Professionals call this temperature.
Going up into an attic and seeing ductwork running every which way is not an uncommon sight.
Well there s not a universal fixed temperature your ac should always be blowing.