This unit is used to cool a computer room, I have been having this problem for a couple of years now. Most of the time the unit works flawlessly, but during periods like spring and fall when the outside temp is between 70-75 the temp will climb inside to above 78F, the thermostat is set at 71F. When the temp rises above 80F the unit begins to work notmally, or during winter when the outside temp is below 70 everything works well also. Have had multiple service calls and tech onsite and with no resutls. Have changed the comptuer board in the unit with no improvement.

Any ideas?

Thanks

Ken Zeleny
Sacramento Credit Union