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I apologize for not getting to this sooner but I wanted by make sure my
analysis was "real".<br><br>
The PVAV systems are set with COOL-CONTROL = CONSTANT. That is
driving up both the cooling energy and the reheat energy.<br><br>
The zone air flows are self-sized and the minimum flow is too low for
heating. When you change the glazing in some of the windows, the
zone air flows change, skewing the results. I am pretty sure that a
"real world" project would have fixed air flows to the
zones. In order to gain some understanding of how the change in
glazing affects the building you would want to program the zone air flows
to be the same between the three runs - Base Case, EEM 1, EEM 2.
<br><br>
There is no central heating coil. As a result, air is delivered to
the zones at much lower temperatures than required to meet the heating
loads. Hence the thousands of hours underheated. <br><br>
First I fixed the zone air flow rates to the values reported in the Base
Case run. The results are more "real":<br>
Cooling energy decreases in each EEM run, heating energy increases as
expected - less heat in the windows, more heating required. <br>
The fan energy also increases as expected, more run hours at higher zone
air flows as this is a VAV system after all. <br><br>
Interestingly though, the total energy remains exactly the same between
all three runs. <br><br>
Next I took the bold step of setting COOL-CONTROL = WARMEST,
MAX-COOL-REHEAT-T = 70.<br>
The base case total energy consumption dropped by 8.5%. <br><br>
The two EEM runs again save cooling energy, the fan energy and heating
energy increase. The result is that EEM 1 saves 0.17% total
energy. EEM 2 saves 0.02% total energy consumption.<br><br>
<br>
I hope that provides something a bit more real.<br><br>
<br>
At 10:29 PM 15/07/2012, Peter Baumstark wrote:<br><br>
<br>
<blockquote type=cite class=cite cite="">Wow, it looks like the airflow
is throwing it off, somehow. I ran a case where I Auto-sized the
airflow, and it's giving me more reasonable numbers for energy
"differences" in pre and post case. However the baseline
energy use for the building (auto-sized case) is about 25% below the
building's actual usage.<br><br>
I have to think about how a reduction in airflow can make such a
difference when evaluating fenestration products.<br><br>
Pete<br><br>
<br>
<font face="Tahoma" size=2><b>From:</b> Peter Baumstark
<pbaumstark@sbcglobal.net><br>
<b>To:</b> Chris Jones <cj@enersave.ca><br>
<b>Sent:</b> Sun, July 15, 2012 6:21:29 PM<br>
<b>Subject:</b> Re: [Equest-users] Unexpected Custom SHGC Results<br>
</font><br>
Or actually here's a run with actual EEM runs, if that's more straight
forward to evaluate.<br><br>
Thank you,<br>
Pete<br><br>
<br>
<br>
<font face="Tahoma" size=2><b>From:</b> Peter Baumstark
<pbaumstark@sbcglobal.net><br>
<b>To:</b> Chris Jones <cj@enersave.ca><br>
<b>Sent:</b> Sun, July 15, 2012 6:09:40 PM<br>
<b>Subject:</b> Re: [Equest-users] Unexpected Custom SHGC Results<br>
</font><br>
Sure Chris, if you have a few minute to look at it, here it is.
Thank you very much for your time.<br><br>
Pete<br><br>
</blockquote><br><br>
<x-sigsep><p></x-sigsep>
>><br>
Christopher Jones, P.Eng.<br>
Suite 1801, 1 Yonge Street<br>
Toronto, ON M5E1W7<br>
Tel. 416-203-7465<br>
Fax. 416-946-1005<br>
email cj@enersave.ca<br>
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