Hi Erik,
Yes, I should have mentioned that I tried that too. That is typically
what I do, but I thought perhaps defining a heat source with a small
amount of capacity would be a reasonable way to alleviate the "free"
heat energy I appear to be getting...
Attached is a quick and dirty wizard model that illustrates the issue
(you will need to download .bin file or change to something
comparable). This is representative of the configuration I was going
for except air-cooled DX.
David
Hi all,
I am modeling a PIU system w/ a water-cooled DX coil and series electric
FPBs; no central or preheat heating coils. Using eQ v3.64
SV-A report indicates heating capacity for system is 0.
Despite this configuration, hourly reports of for SYSTEM, 'Total central
heat coil output (Btu/hr)' indicates there is varying amount of central
heat energy output in the first 1-2 and in some cases, the last 2-3
hours of many days in heating months (location Seattle, WA). This is
also confirmed by looking at the difference in energy reported between
SS-A Heating and SS-B Zone Heating. It is not necessarily a trivial
amount of energy, ~25% of total.
Have others observed this before, and if so, found a way to fix this?
Can't say I've tried everything I can think of, but this is what I have
tried:
A) Set HEAT-SOURCE = "ELECTRIC" and use a very small capacity both -1 or
-1000
B) A + setting HEAT-CONTROL = "CONSTANT"
C) B + set HEAT-SET-T various values, including minimum (50F)
D) Setting HEATING-SCHEDULE to something that locks out heating. This
works, but also locks out zone heating, so not a viable solution
Thanks in advance for any input.
-David
--
David Reddy
*360 Analytics*
Building Energy Analysis Consultants
mail: 9750 3rd Ave NE, Suite 405, Seattle, WA 98115
office: 206.557.4732 x 201
cell: 206.406.9856
web: www.360-Analytics.com
David,
Have you tried setting the HEAT-SET-T (Hot Deck Max Leaving Temp) to no
value (i.e. Restore Default)? I think that any value for that keyword
enables heating at the AHU level.
-Erik
*Erik Kolderup, PE, LEED AP*
erik at kolderupconsulting.com | 415.531.5198 | www.kolderupconsulting.com