[Equest-users] Follow-up: Evaporative Cooling issues

[jacob goodman]

Forgot to mention: I went through the historical lists and found another 
modeler with this problem and the suggestion was to check humidity 
controls (they are "Not Installed") , I also went through the Hourly 
reports for both models and it looks like the heating is running at a 
higher % of capacity in the Evap model in winter.

Also, the ventilation fans are running at a higher kW... since evap only 
uses can power could this indicate winter cooling that the heaters are 
fighting against?

On 6/5/2015 8:05 AM, jacob goodman wrote:
> Dear List,
> I'm working on a project that is looking to compare simple PSZ rooftop 
> units with Direct evaporitive cooling and gas furnace. When I make the 
> switch, I change "HVAC system type" to Evaporative Cool then add 
> Supply cfm as prompted and "Evaporitive Cooler Type" to Ditect on the 
> air side "Cooling - Evaporitive Cooling" display mode under air side 
> systems.
>
> After these changes I see the expected drop in cooling energy use and 
> a rise in fan energy use since the baseline had small fan power and 
> the evaporative uses the units spec'ed fan power. The strange part is 
> that the heating energy rises significantly. While I made no 
> intentional changed to the heating side of the units I did notice that 
> the monthly peak demands went down while the usage went up sio the 
> heating seems to be running more hours after the change to evap 
> cooling....
>
> Should I just schedule the heater off? I would love to have a more 
> elegant solution.
>
> Attached are two versions of the model before and after the change. 
> Any advice is appreciated.
>
> Thanks!!!!
> Jacob
>