[EnergyPlus_Support] Re: Low Temperature Radiant Cooling Won't Meet Loads

["Jean marais" <jeannieboef@xxxxxxxxx>]

Monitor the surface temp of your radiant system. monitor the mass flow rates. I would hard size the pipes and mass flow rates realistically (the autosizing at the, for radiant system, conditions may be wrong). Hard size. The setpoint in the lowtemprad object should be lower than that of the zone SP by about 2 degC.

For chilled ceiling you'll get realistically a max of 75 W/m2, and for a floor 20-40 W/m2 at Roomtemp 26degC and surface temps 16 degC. These systems are limited by fundimentals of heat transfer via radiation and convection. Even blowing air across to increase the convection transfer has minimal effect. 

Do some hand calcs. Let us know how you get on.



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