[Equest-users] In-duct heating coils

[Sharad Kumar]

Hi Omar,

Please find my responses in blue :

Dear all,
             I have a std VAV system with electric reheat, where we did add
electric heating coils inside the ducts for some zones.
While modelling this case on eQuest; at system level; I did enter the "Heat
Source" as " Not Installed", and the "Zone Heat Source" as "Electric". At
Zone level, I did define a temperature schedule for heated zones. Zones
with no coils were defined as zero "Maximum Heating Rate", and Undefined
schedule.

What I did find in the SV-A report is that; zones with zero max heating
rate still report Heating Capacity,

[SK] One can have the required or zero heating capacity in SV-A report
for these zones by having input some higher value more than 140
degree Fahrenheit as Indoor design heating temperature.
The higher the heating design temperature there is no heating requirement
in that zone.
The heating capacity of any zone is derived by the temperature difference
between design temperature and the outside temperature.
If the design temperature is higher than the outside temperature than there
is no requirement of heating.So the zone is not being heated.

Another problem is that I can't yet define heating capacity limit to heated
zones.
[SK] Kindly check that the heating capacity is input at the system level
and not at the zone level.For  purpose maximum heating rate can be input at
zone level. Heating capacity is a thing of system sizing.

I tried defining electric baseboard heating instead, with equivalent
capacities to my installed coils, but my savings were reported to be very
exaggerated.
[SK] Generally reheat is used for the case like of your purpose.Try using
reheat and reheat delta T to control the unmet load hours and system sizing.

Any help on an appropriate method to modelling this case would be
appreciated.

Thanks,
Sharad.Kumar.
Green Horizon Consulting LLP
Gurgaon
India.

Linked-in
<https://www.linkedin.com/profile/view?id=151208255&trk=nav_responsive_tab_profile>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20150616/f971d72a/attachment.htm>