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5.7.5.2 - Single-zone VAV descriptors #215

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
What NACM Section(s) are relevant to this issue?
5.7.2.4 - Heating Supply Air Temperature Control
5.7.5.2 Heating Supply Air Temperature By Stage 
and other Single-zone VAV descriptors

Explanation of issue:
Staged Setpoint is not listed in the list of choices for Heating Supply Air 
Temperature Control, despite the 5.7.5.2 Heating Supply Air Temperature By 
Stage descriptor indicating this is the valid control option (similar to 
cooling SAT control choices).

Proposed resolution:
Add Staged Setpoint to Heat SAT Control descriptor

Please provide any additional information below.

Original issue reported on code.google.com by da...@360-analytics.com on 2 May 2013 at 8:14

GoogleCodeExporter commented 9 years ago 
Made change in version 2.2

Original comment by JohnJArent on 23 May 2013 at 6:57

GoogleCodeExporter commented 9 years ago 
John, 
There are some pretty substantial differences between how controls are 
described in the CBECC tool and how they are described in the ACM.  I think the 
intent of what controls are supported in CBECC are more or less in-line with 
the ACM, but I think it is worth having a call/demo to describe how these have 
been implemented, and review if these changes require ACM updates.

Let me know if you are interested in a demo/call to discuss and I'll set up a 
Doodle poll.

Original comment by da...@360-analytics.com on 24 Sep 2013 at 7:09

GoogleCodeExporter commented 9 years ago 
John will make ACM updates to reflect current approach:

AirSys = SZACVAV
2spd cooling coil
VSD fan with min 0.5 flow ratio
Furnace heating
Warmest zone reset between 55 and 95F

DR: Need to confirm reset priority method (flow or temp first)

Original comment by da...@360-analytics.com on 7 Nov 2013 at 7:16

GoogleCodeExporter commented 9 years ago 
Made updates to ACM (v3 release, expected late November).

Original comment by JohnJArent on 19 Nov 2013 at 11:34

GoogleCodeExporter commented 9 years ago

Original comment by JohnJArent on 19 Nov 2013 at 11:34

GoogleCodeExporter commented 9 years ago 
David, see the attached revisions to section 5.7.5.2. I think the ACM intent is 
carried out in CBECC, as you mention, so if this language needs further 
tweaking, maybe we can have a brief call this Friday 11/22, or early next week, 
so we can close this one out.

Original comment by JohnJArent on 21 Nov 2013 at 11:49

Attachments:

GoogleCodeExporter commented 9 years ago

Original comment by JohnJArent on 21 Nov 2013 at 11:50

GoogleCodeExporter commented 9 years ago 
John,
I am confused, the SZVAV revisions now only have a Standard Design rule for 
supply fan low speed limits, no rules for capacity fractions or other 
properties of baseline SZVAV systems.

Also, how do the following descriptors play into the CBECC compliance analysis:

Duct Leakage Rate
Airflow Adjustment Factor 
Refrigerant Charge Factor

Original comment by da...@360-analytics.com on 25 Nov 2013 at 10:23

GoogleCodeExporter commented 9 years ago 
David, please review the attached language for single-zone VAV related building 
descriptors and verify that this is consistent with our implementation.  I 
removed the airflow adjustment factor and refrigerant charge factor.

I also removed the custom curve fit language for the SEER/EER equipment below 
65 kBtu/h.

Original comment by JohnJArent on 3 Dec 2013 at 9:00

Attachments:

GoogleCodeExporter commented 9 years ago 
John, 
The only discrepency is that The low speed SZVAV fan power is governed by the 
fan curve and the min flow, which is set to Max(0.5*Fan Capacity, Required Vent 
Rate).  I think this is a trivial difference, so closing issue.  Let me know if 
you have any questions on the implementation.

Original comment by da...@360-analytics.com on 15 Feb 2014 at 7:44