I am using energy balance chart to understand the interaction of the radiant heat released by the process into my zones and it´s effect on the heating and cooling demand on the space. My space has high density of process power load. When I input the process loads to my zones and set the fraction of radiant heat to 0, this resultant energy balance chart is as follows:
I do not understand why the process heat is still a part of the load balance chart when I say that the heat given out by the equipment is 0.
Going further, when I set the fraction of radiant heat to my zones as 1, the resultant energy balance chart is as follows:
Why is the total energy demand decreasing in this case as well?
Can somebody help me understand these energy balance? I have setup an ideal air system and I have ventilation demand for my zones as well.
My understanding is if you set your radiant heat fraction to 0 then the heat associated from that gain is experienced purely as a convection gain - ie directly warms the air in your space.
If you’re using an ideal air system I assume your system is controlling the air temperature to a setpoint, and so your cooling load will higher when the radiant fraction is low compared to when it’s high (when the radiant fraction is high the surfaces of your zone will experience a greater increase in temperature than the air)
Thank you for responding. If the implication is that the heat generated during the process will be introduced into my space regardless of whether I set the radiant heat fraction to 0 or 1, is there a method to configure my model to indicate that none of the equipment’s heat contributes to warming the air in my space? This is because I have a chilled water line that primarily cools down the equipment, and not all of the equipment’s heat is transferred to the air in my space.
It looks like HB handles this through the lost_fract input, which allows you to assign a portion of the gain that doesn’t get applied to the HVAC system and room heating/cooling balance
Thank you so much for this. I don´t know how I missed it but you just saved me from a problem that I have been trying to understand and solve forever!! I really appreciate your prompt help.
Can you also tell me how I can get zonewise energy balance charts?
Do you mean how to get a load balance chart for each room?
Based on this I expect if you plug in a list of your rooms and right click unflatten (or maybe even graft) the _rooms_model input that will hopefully produce a load balance per room.
If that doesn’t work you might need to experiment with variations on grafting and potentially even changing the expected input type.