[Equest-users] Can you use eQuest for PMV calculations?

[Neil Bulger]

Alex you are correct, eQuest does not know the surface temperatures required to calculate the Mean Radiant Temperature. eQuest /DOE2 uses the Cooling Load Temperature Difference (CLTD) method to arrive at heat loads in a space. This approach makes approximations of the radiant component of heat transfer and does not directly calculate radiant gains or losses. Because of this, any DOE2 based software at best can predict air temperature and moisture needed for a PMV calc.

EnergyPlus or IES are the only engines that can produce hourly surface temp information and therefore, mean radiant temperature averages.

If you are interested in providing comfort feedback of envelope changes and not HVAC changes, learning EnergyPlus using OpenStudio from NREL is well worth the time and effort. Their workflow takes some practice to adopt but once you get the hang of things, creating buildings is very easy. Their youtube channel is best for explaining this, search for OpenStudio and NREL.

Neil Bulger
Project Engineer
________________________________
I N T E G R A L
                          GROUP

427 13th Street, Oakland CA 94612
510 663 2070 x 235
nbulger at integralgroup.com<mailto:nbulger at integralgroup.com>
www.integralgroup.com<http://www.integralgroup.com/>
DEEP GREEN Engineering.
________________________________

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Alex Krickx
Sent: Thursday, April 12, 2012 9:13 AM
To: Kathryn Kerns
Cc: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Can you use eQuest for PMV calculations?

I'll second the suggestion to purchase the Thermal Comfort tool. It is easy to use. I believe that a newer version was recently released - we're still using the 1994 version.

However, I'm not sure that it solves Jason's problem - it still requires a user-entered Mean Radiant Temperature which I don't believe eQUEST gives as an output.

When we use the tool (specifically for perimeter comfort analysis understanding the impact of different glazing options on comfort) we make some assumptions on wall/floor/ceiling temps, some calculations on glass-temperatures, and some further assumptions on the ratio of glass-to-other surfaces from the occupant's perspective. Based on that we can calculate the PMV for that single point time with those conditions.

I've used software in the past that was able to calculate PMV for every hour of the year (so every hour it would combine air temp, a calculated MRT based on surface temps, humidity, etc) and then give an output for how comfortable the space was throughout the year (with hourly outputs of PMV for different spaces).  I don't believe that eQUEST gives the necessary information (surface temps) to do this type of analysis.

I included Jeremiah's response below which suggests that Energy Plus can do these calculations. This was my impression, however I have never used E+ to do them.

Kind regards,
Alex

Alex Krickx, LEED AP
Building Energy Specialist
Serious Energy, Inc.
1250 Elko Dr, Sunnyvale, CA 94089
(t) 408.541.8124
akrickx at seriousenergy.com

The information contained in this e-mail and any attachments may be confidential, proprietary and/or privileged. If you are not the intended recipient then you have received it in error and any review, distribution or copying of this message and any attachments is prohibited and you are to notify the sender immediately by reply e-mail and delete immediately this message and any attachments.



________________________________
Energy Plus does PMV and inside surface temperatures as well...

Jeremiah D. Crossett
CleanTech Analytics
503-688-8951
www.cleantechanalytics.com<http://www.cleantechanalytics.com>


From: Kathryn Kerns [mailto:kathryn.kerns at bceengineers.com]
Sent: Thursday, April 12, 2012 8:58 AM
To: Alex Krickx
Cc: equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] Can you use eQuest for PMV calculations?

Alex, ASHRAE sells a Thermal Comfort program which will do these calculations for you based on temperature, humidity, air speed, etc. It doesn't cost much and is easy to use. Check the ASHRAE website for things to purchase.

________________________________
From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> on behalf of Alex Krickx
Sent: Wed 4/11/2012 3:42 PM
To: Jason Quinn; equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Can you use eQuest for PMV calculations?
Hi Jason,

I'm under the impression that eQUEST can't output surface temperatures which are needed to calculate PMV values.

I think an EnergyPlus based program might be a better place to look. I would ask on the Bldg-Sim list for recommendations as it has a broader user-base (this list is eQUEST specific).

Good luck,
Alex

Alex Krickx, LEED AP
Building Energy Specialist
Serious Energy, Inc.
1250 Elko Dr, Sunnyvale, CA 94089
(t) 408.541.8124
akrickx at seriousenergy.com<mailto:akrickx at seriousenergy.com>

The information contained in this e-mail and any attachments may be confidential, proprietary and/or privileged. If you are not the intended recipient then you have received it in error and any review, distribution or copying of this message and any attachments is prohibited and you are to notify the sender immediately by reply e-mail and delete immediately this message and any attachments.


From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Jason Quinn
Sent: Wednesday, April 11, 2012 3:36 PM
To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: [Equest-users] Can you use eQuest for PMV calculations?


Is it possible to use an eQuest model to do thermal comfort PMV (Predicted Mean Vote) calculations per ASHRAE 55/RP884?

If not are there any recommendations?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20120413/8f0d9ce7/attachment-0001.htm>