[Bldg-sim] Need help in IGBC review for energy credits

Nathan Miller nathanm at rushingco.com
Tue Mar 10 07:35:08 PDT 2015

Without knowing the specifics of your project (and based only on the projects I’ve submitted to the USGBC, not IGBC), I’d say:

1)      Heat Rejection is typically energy use for cooling tower fans (or similar system) as opposed to compressors (which usually shows up in Space Cooling category if you are using eQUEST). So the reviewer seems to be confused why there are (significant?) differences in the amount of cooling tower energy use between the baseline and proposed. Can you justify/back up the difference by showing that the energy conservation measures/systems used in the project result in less run-time for cooling tower or significantly more efficient cooling tower operation.

2)      For residential applications, I like to use the calculators provided as part of the Energy Star Multifamily High Rise Program to estimate plug-loads. This is the standard referred to for LEED for Homes Midrise as well.
Guidelines can be found here:

Excel Sheet for calculating plug loads (and DHW loads, and many other useful tools) here:

I would think that if you used this tool to develop your plug loads and submitted it to the reviewer it would be adequate documentation to justify whatever % energy use it comes out to, even if less than 25%. Note that these standards were really developed with the US market in mind, so for an international project you may have to use your discretion to adjust some of the values to be more appropriate for the market.

Hope this helps,

Nathan Miller, PE, LEED AP BD+C – Mechanical Engineer/Senior Energy Analyst
RUSHING | D 206-788-4577 | O 206-285-7100

From: Bldg-sim [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Rasheed Ahmad
Sent: Tuesday, March 10, 2015 10:19 AM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Need help in IGBC review for energy credits

Dear all,

I got review for IGBC green homes for energy credit. And it is as follow;
1.      1) Please provide the details about loads considered under the head of “heat Rejection” and  Explain energy conservation measure to quantify the energy savings
2) 1.      The project has not provided any consumption values for Receptacle, process and equipment loads. Please note that these loads should be considered and default consumption
should be considered as 25% of the total energy cost. For buildings, where the process energy cost is less than 25% of the baseline building energy cost, the
Submittal must include supporting documentation substantiating that process energy inputs are appropriate. Receptacle and Process loads include, but are not limited to, refrigerator, washing machine, television, electric geysers, computers, parking garage exhaust, pumps & motors, elevators, etc.,

It would be very helpful , if any experts can explain what i need to do to reply to these queries.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20150310/e39ff342/attachment.htm>

More information about the Bldg-sim mailing list