Dear Bldg-sim,

I am having some difficulty with the definition of outdoor air reset
temperatures.
Clause G.3.1.3.12 of A90.1 (2007) states:
/The air temperature for cooling shall be reset higher by 2.3degC under
the minimum cooling load conditions./
Question 1: We are not using DOE2 or EQuest. How are the "minimum
cooling load conditions" decided?

Question2: During non-occupancy and cold external conditions, what SA
temperature setpoint should be used? For example, if the air handler
cycles during night to meet Zone heating setpoints, the SAT setpoint
must be close to the RAT otherwise the system will first cool (possibly
by increasing cold outdoor air) and then reheat the air in the zones.

Question 3: For the sake of comparison we generated a file similar to
our model using the E+ example file generator but when we queried it, it
appeared to operate the economiser via a differential enthalpy. A90
appears to stipulate a fixed Dry Bulb shutoff (G3.1.2.7). Is the example
file in error here?

Best regards

Chris Yates