Dear Everone,
We are using new version of Carrier HAP 5.11i software which forces us to set leaving temperature for reheat box. There is no requirement for reheat box temperature in appendix G so there are 2 ways of modeling that case:
1. Reheat LAT can not be set according to G3.1.2.9.1. I assume that for heating purpose of System type 7 airflow rate should be constant minimum required and max reheat temperature should vary based on max heating demand. In our case we set the maximum allowed reheat box LAT in Carrier HAP, or
2. We set Reheat LAT according to ASHRAE G3.1.2.9.1 ( 11.1C + thermostat set point) airflow in heating operation is higher in that case. We can get extra savings.
I want to be sure that method 1 is correct.
Many thanks for help
Tyler Thumma
7GroupLEEDuser Expert
60 thumbs up
April 26, 2019 - 10:03 am
Method 2 is allowed, but is not necessarily the intent of the temperature difference in G3.1.2.9.1, which was more likely established as a cooling setpoint. Another acceptable alternative would be to use a temperature differential that is more consistent with what is used in the Proposed case.