Apache HVAC modeling

[Cristian]

Hi

I wanted to ask you guys about some problems i have with modeling my HVAC system.

I am using a AHU with heat recovery for the fresh air and Fancoil units for the conditioning.

First of all i want to modell a building wich have two source of heating:
- one conventional noncondensing boiler with natural gas and one Heat pump - GWHP

I have setup the time profile for my occupied building between 07:00 - 19:00
I have setup the heating set point to work between 06:00 - 19:30
For this case i wanted to setup two difrent heating set point
1. 18 C when the building is not occupied 00:00 - 06:00 and 19:30 - 24:00
2. 22 C when the building is occupied 06:00 - 19:30
3. The fancoil controller is working when between 06:00 - 19:30 and when the building is not occupied only when the outside temperature drops below 10C - (i have made this condition because for ex: in June when the building is not occupied when the outside temperature is 10-20C and even if the room temperature is 20C the program says that i have to use heating coil wich for me is wierd because my heating set point is 18C )

For this situation i had used 1 Cooling coil and 2 Heating coils.
1. one heating coil will work for the period when the building is occupied and will have as source of heating - one Conventional noncondesing boiler
2. second heating coil is made to function for the time when the building is not occupied but this will have as a source of heating, one Heat Pump - GWHP and as a backup one noncondesing boiler

When i run the program only the Heating coil wich use the convetional boiler is working the second heating coil wich should heat the building when is not occupied is not responding. (romm temperature drops below 18C when the building is not occupied)

What am i doing wrong and what tips do you have to solve these problem.

Thank you.