HW radiator without thermostatic valves

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Posts: 12

HW radiator without thermostatic valves

Postby Helix » Thu May 08, 2014 12:40 pm

Dear DesignBuilder staff,

I need to model a condominium without thermostatic valves with Detailed HVAC in order to show the advantage of this solution.

The problem is that DesignBuilder models the system by varying the amount of water passing into radiators and correcting it according to the thermal zone heating load (by using a bypass for the water enetering into HW radiators).

In reality, without a room control device, the amount of water in a terminal unit remains the same and the only thing that varies is the temperature of the incoming water (which is , in general, a function of the outdoor temperature).

According to this control logic, this corresponds to room overheating (which DB doesn't consider because, as soon as the temperature setpoint is reached in a flat, the heat flow stops).

Is there a way to solve this problem in current DB version?

And, if not, are you trying to consider it for next versions?
Thank you in advance,

Best regards,
Posts: 7

Postby kpx » Tue Sep 09, 2014 5:12 pm

I've modeled a similar case, but in order to do this, I went outside DB and I worked directly on IDF file locking the mass flow rates via EMS. Quite complicated, but I reached what I wanted. And more: to model correctly a thermostatic valve i wrote another basic function via EMS based on zones temperatures, as the energyplus default modulation is based on thermal loads that are not directy detecbable actually

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