[Equest-users] 回复： Indoor fan separation at ARI

[赵永青]

Hi，
You can input the EER in eQUEST wizard mode，and then click the finish button，the EIR generated by eQuest in detailed mode is what you want.And also you can calculate it per Elizabeth's suggestion.


Yongqingzhao

---原始邮件---
发件人: "Elizabeth Gillmor"<elizabeth at energetics-eng.com>
发送时间: 2015年06月09日 22:09:31
收件人: "Omar ElRawy"<omaroelrawy at gmail.com>;
抄送: "equest"<equest-users at lists.onebuilding.org>;
主题: Re: [Equest-users] Indoor fan separation at ARI


I seem to get this comment frequently so I have it all typed out as a stock LEED comment response.&#xA0; The advice you received is correct. You can use the following formulas for fan power and EIR:


kW/cfm = BHP / 0.746 * Fan Motor Efficiency &#xA0; &#xA0; (<----from Appendix G)

&#xA0;

BHP = CFM * 0.0013 + Pressure Drop Adjustment




The baseline EIR is then calculated with fan energy modeled separately, using the following formula (same as what eQuest uses in Wizard mode):




原文图片







Where ARI Fan Power = fan power at rated ARI conditions (W/Btuh), and CAP = total cooling capacity (Btuh).&#xA0; At rated ARI conditions, the supply fan is rated at 0.365 kW/cfm and 400 cfm/ton, such that:






原文图片







When normalizing the cooling capacity, the formula is:

原文图片




 




When applied to a baseline EER=9.5, the resulting EIR=0.3051.&#xA0; The eQuest wizard will also do this for you correctly, but usually at LEED submittal time we are all well past the wizard phase, so the formulas above are handy to have. &#xA0;




Good luck!

Elizabeth









Elizabeth Gillmor &#xA0;PE, LC, LEED AP

e n e r g e t i c s &#xA0;consulting engineers, llc
energetics-eng.com
c 303.619.0091










 
On Tue, Jun 9, 2015 at 3:26 AM, Omar ElRawy <omaroelrawy at gmail.com> wrote:

Dear all,

&#xA0; &#xA0; &#xA0; &#xA0; &#xA0; &#xA0; &#xA0; &#xA0;I've got the following reply for a psz system in the baseline case during preliminary LEED design submittal:




"Note that section G3.1.2.1 requires that where efficiency ratings, such as EER and COP, include fan energy, the descriptor shall be broken down into its components so that supply fan energy can be modeled separately. Because the efficiency ratings are calculated at ARI-rated conditions, the fans should also be broken out at ARI-rated conditions. Most simulation software programs have the capability to perform this step automatically. Provide documentation showing that this calculation has been performed by the software automatically or provide calculations consistent with the ASHRAE 90.1-2007 User’s Manual showing that the calculation has been performed at ARI-rated conditions."




What I did is that I referred to eQuest library, and documented the following paragraph to the reviewer:

"COOLING-EIR:
The Electric Input Ratio (EIR), or 1/(Coefficient of Performance), for the cooling unit at ARI rated conditions..... This EIR is at ARI rated conditions, i.e., without correction for different temperature or part load. Note: If you include fan electric energy consumption in your value of COOLING-EIR, then you should set SUPPLY-KW/FLOW to zero. Otherwise, the supply fan electrical energy will be double counted........ Imbedding the fan energy into the COOLING-EIR is valid only if the fan is constant volume and INDOOR-FAN-MODE = INTERMITTENT; i.e. the fan cycles on/off with the compressor. If the fan runs continuously during occupied hours, or the fan is variable volume, then the fan energy cannot be included in the COOLING-EIR (or HEATING-EIR)."

And I did set fan kw/cfm to zero, intermittent, and constant volume, but I've got the SV-A report reporting zero kw power demand, and zero fan (kw) for the system and its zones.

Then I got an advice stating that:

"You should do what the reviewer mentions, divide the indoor fan from the efficiency rating at ARI-rated conditions and model it separately; this way you will be able to report the appropriate fan power"

My question is:&#xA0;where do I separately input the indoor fan power (kw), and what value should it be?, knowing that this is a baseline case that do not refer to an actual design.

Thanks,
Omar ElRawy, LEED AP BD+CLEED Project Manager
EA Sustainable Building Consultants
http://www.ea-buildingconsultants.com





 
 
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