Dear UMH forum, I am evaluating my first energy model in which I compare radiant heating (ZoneHVAC:HighTemperatureRadiant) against non-radiant heating. The building is a sizeable (10k m2 / 100k sq.ft.) warehouse in ASHRAE Climate Zone 5a. The model is working with no evident problems and I am reporting:
- normal zone dry bulb temp
- operative temperature
- mean radiant temperature
As I review results, I notice: - the difference in these 3 temperatures for a winter DesignDay is tiny, a few tenths of a degree F. - the zone setpoint temperature is inexplicably different than my schedule (69.4F vs. 68F)
My understanding from radiant manufacturers is that acceptable comfort is maintained by radiant heating at significantly lower dry bulb temperatures - this does not appear to be the case in my model. (I "think" that the operative temperature is supposed to reflect the apparent comfort.) I have reviewed the I/O reference and a little of the Engineering Reference, but do not understand why the radiant system operates with so little difference between the various "types" of zone temperature.
Can you share insights, please?
p.s., there is an air loop which I have temporarily given very low capacity in order to see the impact of radiant more clearly.
