Procedures For testing A/ C Units
Assuming you have convinced the owner to let you test CS on his facility, the following
are the steps that should be followed.
1. Use the pre test question sheet to determine the status, type, etc. and any other
pertinent information listed on the sheet.
2. Visibly go over the units to be treated and look for anything that oblivious about
the units that would cause concern. (frozen coils, no sweat back on suction lines,
short cycling, etc.)
3. If everything seems to be in order, establish what the client would like for you to
measure. (discharge air temp., amp draw, run time, pressures, etc.)
4. From this conversation the correct information logging equipment should be
determined. These pieces of equipment will be discussed later.
5. Using the Pre Test Data sheet fill out all pertinent information. (type of
equipment, model numbers, amp draw, pressures, discharge air temp, return air
temp. etc.)
6. Usually amp draw, run time and discharge air temperature will be all that is
needed.
7. First I would use the Hobo State recorder (H06-001-02) and the RIBGTA contact
sensor to record when the unit is on or off. Program the Hobo from your laptop
with the parameters for the job (name of job, date / time to start and stop, intervals
of time to take readings). Secure the state recorder somewhere in side the
electrical part of the unit (cable ties work well) and hook the current sensor
around one of the leads going directly to the compressor. (always hook between
the contactor and compressor) This sensor should now be adjusted, per the
instructions, for the high and low amp readings. Plug the cable into the state
recorder and validate the green light comes on. It is now recording when the
compressor comes on and goes off. In a 2 stage unit it is imperative to do both
compressors. Showing run time on the 2nd compressor is invaluable.
8. Second install in the same manner the amp recorder. This will give an accurate
log of amperage usage before and after the test. I us the HOBO Temp/external
(HO8-002-02) and the Onset CTV_B current sensor (0-50 amps).
9. If discharge air temp is to be monitored, I use the EL-USB-1 Temperature Data
Logger. This device can be programmed and simply clipped to the supply air
diffuser. It can be purchased online thru the TheDataLoggerStore.com.
10. Let all recorders run for a predetermined length of time ( I like at least a week)
before injecting the system with CS.
11. Let the recorders run for an equal or more amount of time after the treatment.
Collect the loggers and using Boxcar Pro Software for the Hobo’s and the
supplied software for the EL temp. logger , chart the changes and prepare the
proper documentation for the client.