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eQUEST Furnace Preheat Coil Energy

Hi folks, I recently run into a situation that eQUEST doesn't count the natural gas consumption of preheat coil. I have googled and no luck on the solution, and I am looking for help on UNMET HOURS.

I have tried the model in both 3.64 and 3.65 beta (v7174).

This is my model inputs: TYPE = PSZ; HEAT-SOURCE = HEAT-PUMP; MAX-SUPPLY-T = 95; PREHEAT-SOURCE = FURNACE; PREHEAT-T = 60; TMY3 file is Boeing Field, Seattle.

The system is serving corridors and operating 24/7. The simulation result indicates there is no space-heating related gas consumption in BEPU, BEPS, or PS-F report. However, the hourly report indicates the preheat coil is operating to meet 60°F preheat air temperature. Also, the SS-B report shows the preheat coil energy consumption for the system, which is consistent with the preheat coil load hourly report add-up. Therefore, I assumed the preheat coil consumption on SS-B report to be correct and manually add that to the annual energy consumption with furnace efficiency modification.

If I switch the PREHEAT-SOURCE to ELECTRIC, the preheat coil electricity consumption is shown on BEPU, BEPS, and PS-F report. The annual space energy difference is consistent with the preheat coil load hourly report add-up.

Have you experienced any similar issue? Do you have a solution for this situation? Do you know any additional preheat coil heat source aren't compatible with eQUEST?

Best Regards,

eQUEST Furnace Preheat Coil Energy

Hi folks, I recently run into a situation that eQUEST doesn't count the natural gas consumption of preheat coil. I have googled and no luck on the solution, and I am looking for help on UNMET HOURS.

I have tried the model in both 3.64 and 3.65 beta (v7174).

This is my model inputs: TYPE = PSZ; HEAT-SOURCE = HEAT-PUMP; MAX-SUPPLY-T = 95; PREHEAT-SOURCE = FURNACE; PREHEAT-T = 60; TMY3 file is Boeing Field, Seattle.

The system is serving corridors and operating 24/7. The simulation result indicates there is no space-heating related gas consumption in BEPU, BEPS, or PS-F report. However, the hourly report indicates the preheat coil is operating to meet 60°F preheat air temperature. Also, the SS-B report shows the preheat coil energy consumption for the system, which is consistent with the preheat coil load hourly report add-up. Therefore, I assumed the preheat coil consumption on SS-B report to be correct and manually add that to the annual energy consumption with furnace efficiency modification.

If I switch the PREHEAT-SOURCE to ELECTRIC, the preheat coil electricity consumption is shown on BEPU, BEPS, and PS-F report. The annual space energy difference is consistent with the preheat coil load hourly report add-up.

Have you experienced any similar issue? Do you have a solution for this situation? Do you know any additional preheat coil heat source aren't compatible with eQUEST?

Best Regards,