<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hi Jason,</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Regarding modeling the efficiency of equipment...</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
It depends on whether you're modeling a specific system for a specific building project, or if you're trying to model generalized performance, for example for research. I'll comment on the latter scenario. For generalized research purposes, where we don't
know the exact heat pump system and configuration, my team has found that energy simulation results are too sensitive to many of the heat pump details in the energy model. Therefore, to avoid our results being overly-specific to one heat pump model and configuration
we've done one of the following two things.</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<ol start="1" data-editing-info="{"applyListStyleFromLevel":false,"orderedStyleType":1}" style="margin-top: 0px; margin-bottom: 0px; list-style-type: decimal;">
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<div class="elementToProof">We've output the annual heating and cooling demands from tour energy model, then applied the heat pump heating or cooling COPs in a spreadsheet. We've found the COPs from a published study with realized, weather-dependent, COPs
(from representative climates and buildings)</div>
<div class="elementToProof"><br>
</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<div class="elementToProof">We've also done this with hourly performance, based on realized, weather-dependent COPs at different temperatures from representative field studies. For interpolation, we've calculated the maximum possible COP (based on the Carnot
Cycle) for each time step, then scaled those values down to something more realistic, based on the results from the published field studies.</div>
<div class="elementToProof"><br>
</div>
</li></ol>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Hope this helps.</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Best,</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Holly</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div class="elementToProof" style="margin: 0px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<table class="elementToProof" style="text-align: left; background-color: white; color: rgb(36, 36, 36); box-sizing: border-box; border-collapse: collapse; border-spacing: 0px;">
<tbody>
<tr>
<td class="elementToProof" style="width: 86.5976px; height: 84.6667px; text-align: left; padding-right: 5.4pt; padding-left: 5.4pt; word-break: break-word; box-sizing: border-box;">
<p class="elementToProof" style="text-align: left; margin: 0px; font-family: Calibri, sans-serif; font-size: 11pt;">
<span style="color: black;"><img alt="A black and white letter h
Description automatically generated" data-olk-copy-source="MessageBody" width="56" height="67" size="4560" contenttype="image/png" style="width: 56px; height: 67px; min-width: auto; min-height: auto; margin: 0px;" data-outlook-trace="F:2|T:2" src="cid:0af21394-bb76-43b5-aa12-b716edd73e0c"></span></p>
</td>
<td class="elementToProof" style="width: 454.444px; height: 84.6667px; text-align: left; padding-right: 5.4pt; padding-left: 5.4pt; vertical-align: top; word-break: break-word; box-sizing: border-box;">
<p class="elementToProof" style="text-align: left; margin: 0px; font-family: Calibri, sans-serif; font-size: 11pt;">
<span style="font-size: 10pt; color: black;"><b>Holly Samuelson</b></span></p>
<p class="elementToProof" style="text-align: left; margin: 0px; font-family: Calibri, sans-serif; font-size: 11pt;">
<span style="font-size: 10pt; color: black;">Associate Professor of Architecture</span></p>
<p class="elementToProof" style="text-align: left; margin: 0px; font-family: Calibri, sans-serif; font-size: 11pt;">
<span style="font-size: 10pt; color: black;">Harvard University | Graduate School of Design </span></p>
<p class="elementToProof" style="text-align: left; margin: 0px;"><span style="font-family: Calibri, sans-serif; font-size: 10pt; color: rgb(0, 0, 0);"><a href="http://www.hollysamuelson.com/" id="OWA4b496ed7-cc44-0b11-ab88-26eab5345110" class="OWAAutoLink" style="margin: 0px;">www.hollysamuelson.com</a></span></p>
</td>
</tr>
</tbody>
</table>
<div class="elementToProof" style="margin: 0px; font-family: Calibri, sans-serif; font-size: 9pt; color: rgb(33, 33, 33);">
<span style="background-color: rgb(255, 255, 255);"><i>Unless otherwise noted, I do not expect a reply outside your normal working hours. </i></span></div>
<div class="elementToProof" style="margin: 0px; font-family: Tahoma; font-size: 13px; color: rgb(136, 136, 136);">
<br>
</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div id="appendonsend"></div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<hr style="display: inline-block; width: 98%;">
<div dir="ltr" id="divRplyFwdMsg"><span style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> Bldg-sim <bldg-sim-bounces@lists.onebuilding.org> on behalf of bldg-sim-request@lists.onebuilding.org <bldg-sim-request@lists.onebuilding.org><br>
<b>Sent:</b> Thursday, April 10, 2025 4:00 PM<br>
<b>To:</b> bldg-sim@lists.onebuilding.org <bldg-sim@lists.onebuilding.org><br>
<b>Subject:</b> Bldg-sim Digest, Vol 209, Issue 2</span>
<div> </div>
</div>
<div style="font-size: 11pt;">Send Bldg-sim mailing list submissions to<br>
bldg-sim@lists.onebuilding.org<br>
<br>
To subscribe or unsubscribe via the World Wide Web, visit<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" id="OWA4351b8a9-4eeb-c7e9-90dd-5180b981c67c" class="OWAAutoLink" data-auth="NotApplicable">
http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>
or, via email, send a message with subject or body 'help' to<br>
bldg-sim-request@lists.onebuilding.org<br>
<br>
You can reach the person managing the list at<br>
bldg-sim-owner@lists.onebuilding.org<br>
<br>
When replying, please edit your Subject line so it is more specific<br>
than "Re: Contents of Bldg-sim digest..."<br>
<br>
<br>
Today's Topics:<br>
<br>
1. How do you model minimum and high efficiency DX cooling and<br>
heat pump equipment? (Jason Glazer)<br>
2. Re: How do you model minimum and high efficiency DX cooling<br>
and heat pump equipment? (chris.malcolm.yates@gmail.com)<br>
<br>
<br>
----------------------------------------------------------------------<br>
<br>
Message: 1<br>
Date: Thu, 10 Apr 2025 08:28:44 -0500<br>
From: Jason Glazer <jglazer@gard.com><br>
To: bldg-sim@onebuilding.org<br>
Subject: [Bldg-sim] How do you model minimum and high efficiency DX<br>
cooling and heat pump equipment?<br>
Message-ID: <bf88e843-c541-47e9-9462-0ff92a23c74a@gard.com><br>
Content-Type: text/plain; charset=UTF-8; format=flowed<br>
<br>
I just posted a question on unmet hours:<br>
<br>
<a href="https://unmethours.com/question/101487/how-do-you-model-minimum-and-high-efficiency-dx-cooling-and-heat-pump-equipment/" id="OWA769e4e99-56a8-a561-a3d7-5feff22b1527" class="OWAAutoLink" data-auth="NotApplicable">https://unmethours.com/question/101487/how-do-you-model-minimum-and-high-efficiency-dx-cooling-and-heat-pump-equipment/</a><br>
<br>
"I?m trying to get an understanding of the practice of<br>
modelers when comparing minimum efficiency and<br>
high-efficiency DX equipment and heat pumps for different<br>
applications. I know that detailed performance data is<br>
sometimes difficult to get. How successful have you been in<br>
trying to get detailed performance data from vendors? If you<br>
can?t get data like that, how do you model the equipment?<br>
How do you model the indoor fan? If you know it is<br>
multispeed, how do you figure out those details? What if all<br>
you have is the AHRI data (EER/EER2, SEER2/IEER, COP at<br>
17/47, capacities, full load/intermediate/minimum airflows)<br>
what assumptions do you have to make? What performance<br>
curves do you use? If you can get data from the<br>
manufacturer, what assumptions do you still need to make? Is<br>
it different for residential size equipment than commercial?"<br>
<br>
If you can respond to this email or post a response on<br>
unmethours, I would appreciate it.<br>
<br>
Thanks<br>
<br>
Jsaon<br>
<br>
<br>
--<br>
Jason Glazer, P.E., BEMP, GARD Analytics, ASHRAE 209 chair<br>
Admin for onebuilding.org building performance mailing lists<br>
<br>
<br>
<br>
------------------------------<br>
<br>
Message: 2<br>
Date: Thu, 10 Apr 2025 15:47:12 +0100<br>
From: <chris.malcolm.yates@gmail.com><br>
To: "'Jason Glazer'" <jglazer@gard.com>, <bldg-sim@onebuilding.org><br>
Subject: Re: [Bldg-sim] How do you model minimum and high efficiency<br>
DX cooling and heat pump equipment?<br>
Message-ID: <000801dbaa27$72659cf0$5730d6d0$@gmail.com><br>
Content-Type: text/plain; charset="UTF-8"<br>
<br>
Hi Jason,<br>
<br>
I asked this question over a decade ago to a couple of different suppliers in the UK. What intrigued me was the very high efficiency that suppliers (e.g., Mitsubishi, Daikin) quoted - figures that we just plugged into building code calculations. Based on these
figures it seemed like a no-brainer to just rip out centrifugal chillers and replace them with acres of DX systems! My enquiries came to little. The only interesting thing that I got (from a Danish academic) was that the market was very Germany-centric which
resulted in SEER & COP being established at what seemed like, for the UK at least, quite extreme temperature bins.<br>
<br>
The impression I got is that, locally, there is some design experience within the sales teams but it's limited to sizing. The best I got back in terms of energy was something along the lines of "we've got some boffins over in Japan, we can try asking them."<br>
<br>
I don't doubt that they have some very clever people. Are they clever enough to get centrifugal-like performance out of a scroll compressor? I don't know. Reading your message, it's interesting to see that maybe the US market is subject to the same "black box"
issues!<br>
<br>
Good luck. I'll keep an eye on this thread and Unmet hours.<br>
<br>
Cheers<br>
<br>
Chris<br>
<br>
-----Original Message-----<br>
From: Bldg-sim <bldg-sim-bounces@lists.onebuilding.org> On Behalf Of Jason Glazer via Bldg-sim<br>
Sent: 10 April 2025 14:29<br>
To: bldg-sim@onebuilding.org<br>
Subject: [Bldg-sim] How do you model minimum and high efficiency DX cooling and heat pump equipment?<br>
<br>
I just posted a question on unmet hours:<br>
<br>
<a href="https://unmethours.com/question/101487/how-do-you-model-minimum-and-high-efficiency-dx-cooling-and-heat-pump-equipment/" id="OWA762b399a-8678-482e-b0a4-1e5d377a3f28" class="OWAAutoLink" data-auth="NotApplicable">https://unmethours.com/question/101487/how-do-you-model-minimum-and-high-efficiency-dx-cooling-and-heat-pump-equipment/</a><br>
<br>
"I?m trying to get an understanding of the practice of modelers when comparing minimum efficiency and high-efficiency DX equipment and heat pumps for different applications. I know that detailed performance data is sometimes difficult to get. How successful
have you been in trying to get detailed performance data from vendors? If you can?t get data like that, how do you model the equipment?<br>
How do you model the indoor fan? If you know it is multispeed, how do you figure out those details? What if all you have is the AHRI data (EER/EER2, SEER2/IEER, COP at 17/47, capacities, full load/intermediate/minimum airflows) what assumptions do you have
to make? What performance curves do you use? If you can get data from the manufacturer, what assumptions do you still need to make? Is it different for residential size equipment than commercial?"<br>
<br>
If you can respond to this email or post a response on unmethours, I would appreciate it.<br>
<br>
Thanks<br>
<br>
Jsaon<br>
<br>
<br>
--<br>
Jason Glazer, P.E., BEMP, GARD Analytics, ASHRAE 209 chair Admin for onebuilding.org building performance mailing lists<br>
<br>
_______________________________________________<br>
Bldg-sim mailing list<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" id="OWAf2342c8d-a078-a7a8-f6c1-5193ecaaaa9d" class="OWAAutoLink" data-auth="NotApplicable">http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>
To unsubscribe from this mailing list send a blank message to BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG<br>
<br>
<br>
<br>
------------------------------<br>
<br>
Subject: Digest Footer<br>
<br>
_______________________________________________<br>
Bldg-sim mailing list<br>
Bldg-sim@lists.onebuilding.org<br>
<a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" id="OWAb0a4738c-4c73-b3d0-2e68-a6b0e3259e11" class="OWAAutoLink" data-auth="NotApplicable">http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>
<br>
<br>
------------------------------<br>
<br>
End of Bldg-sim Digest, Vol 209, Issue 2<br>
****************************************</div>
</body>
</html>