View Full Version : New AC runs 24/7.
hrc1229
Jul 28, 2010, 08:25 PM
Our new Carrier Comfort Series was installed with a Honeywell dehumidifier. The air handler runs 24/7. We also have to have the system set to 71 degrees to feel cool. Our old system was usually set to 75 degrees. We were told to set the Honeywell thermostat to ON all the time. Should the air handler be running all the time? Why is the new system not as cool as our old less efficient one? Should the dehumidifier have an effect on the AC system running?
wmproop
Jul 28, 2010, 08:57 PM
These are questions you should ask the installer,how long has it been? No the airhandler shouldn`t be running all the time,call the installer back out,its possible it is low on refrigerant
KISS
Jul 28, 2010, 11:23 PM
Arrgh: I can't find the "Comfort Curve", but it's in my HVAC reference materials. See: OSH Answers: Thermal Comfort for Office Work (http://www.ccohs.ca/oshanswers/phys_agents/thermal_comfort.html)
Anyway there is this curve which uses summer/winter, temperature and RH and the % of people comfortable.
If the dehumidifier was really smart, it would use this comfort curve, temperature and RH and adjust the humidity.
If it was of average intelligence, it would control the fan based on it's humidity setpoint. It would turn on based on an indoor sensor and off based on the RH in the return duct.
Somebody is pulling your leg.
Dehumidifiers essentially make it more comfortable without excessively cooling the air hence possibly saving energy.
The best a stupid thermostat can do is run the system longer to reduce humidity, but it cannot control it.
Something is seriously wrong here. Can you post some info about the Carrier system like model #'s of unit and thermostat?
hrc1229
Jul 29, 2010, 07:06 AM
Arrgh: I can't find the "Comfort Curve", but it's in my HVAC reference materials. See: OSH Answers: Thermal Comfort for Office Work (http://www.ccohs.ca/oshanswers/phys_agents/thermal_comfort.html)
Anyway there is this curve which uses summer/winter, temerature and RH and the % of people comfortable.
If the dehumidifier was really smart, it would use this comfort curve, temperature and RH and adjust the humidity.
If it was of average intelligence, it would control the fan based on it's humidity setpoint. It would turn on based on an indoor sensor and off based on the RH in the return duct.
Somebody is pulling your leg.
Dehumidifiers essentially make it more comfortable without excessively cooling the air hence possibly saving energy.
The best a stupid thermostat can do is run the system longer to reduce humidity, but it cannot control it.
Something is seriously wrong here. Can you post some info about the Carrier system like model #'s of unit and thermostat?
The model number is 24ACB7 for the AC, the dehumidifier is a Honeywell, but I'm not sure of the model number.
hrc1229
Jul 29, 2010, 07:09 AM
these are questions you should ask the installer,how long has it been? no the airhandler shouldn`t be running all the time,call the installer back out,its possible it is low on refrigerant
Thanks, I did call the installer and they've come once with no result so they are coming again next week. They agreed that the air handler should not be running all the time.
The unit was installed 3 weeks ago. It is cooling at least, when I set it for 72 the thermostat reads 72. It just seems that we used to always have the thermostat set at 75 or 76. Maybe that's not a big deal.