One of the other differences between this model and the variable flow hydronic radiant
system is that the constant flow radiant system has a built-in local secondary loop. It will
recirculate flow coming out of the system and mix this with flow from the loop to arrive at the
desired inlet temperature to the radiant system (note that this model has the temperature
sensor AFTER the pump to insure proper inlet temperature to the radiant system). The local
loop also contains a pump which is assumed to be upstream of the radiant system and after
the mixing valve. So, the local loop can have some recirculation. The flow from the main loop
may also bypass the radiant system if more than enough flow is available and the main loop
is also a constant flow system.
Vaibhav Jain
On 3 August 2012 16:40, Vaibhav Jain
<vaibhav.energyarchitect@xxxxxxxxx> wrote:
Hello everyone!
I have modeled radiative units (ZONEHVAC:LOWTEMPERATURERADIANT:CONSTANTFLOW) on the floor of the zones. The loops and connections seems to be modeled fine as of now since there are no severe errors, though I have to check more. But I am getting the following warning concerning the flow mismatch. Does this (WaterRecircRate) mean that the volumetric flow rate of the water returning from the demand side is not matching with the rate of water which went into the unit? Or is it something else? How should it be resolved? For info: I am using only District Cooling as the heat source.
** Warning ** Flow mismatch in radiant system--result will be an energy imbalance--should not get this error
** ~~~ ** WaterRecircRate=-8.00E-002, in Radiant System=EAST ZONE RADIANT FLOOR,
** ~~~ ** During Warmup, Environment=CHICAGO ANN CLG 1% CONDNS DB=>MWB, at Simulation time=07/21 19:00 - 19:10
Thank you!