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Dear Bldg-sim,<br>
<br>
I am having some difficulty with the definition of outdoor air reset
temperatures.<br>
Clause G.3.1.3.12 of A90.1 (2007) states:<br>
<i>The air temperature for cooling shall be reset higher by 2.3degC
under the minimum cooling load conditions.</i><br>
Question 1: We are not using DOE2 or EQuest. How are the "minimum
cooling load conditions" decided?<br>
<br>
Question2: During non-occupancy and cold external conditions, what
SA temperature setpoint should be used? For example, if the air
handler cycles during night to meet Zone heating setpoints, the SAT
setpoint must be close to the RAT otherwise the system will first
cool (possibly by increasing cold outdoor air) and then reheat the
air in the zones.<br>
<br>
Question 3: For the sake of comparison we generated a file similar
to our model using the E+ example file generator but when we queried
it, it appeared to operate the economiser via a differential
enthalpy. A90 appears to stipulate a fixed Dry Bulb shutoff
(G3.1.2.7). Is the example file in error here?<br>
<br>
Best regards<br>
<br>
<div class="moz-signature">-- <br>
<div>
<p>Chris Yates <span style="color: rgb(79, 98, 40);">C Eng
MCIBSE</span></p>
<p><i style="">Building Physics Consultant<o:p></o:p></i></p>
<p>Tel:<span style=""> </span>+447960731576</p>
<p>Email: <a class="moz-txt-link-abbreviated" href="mailto:chris.malcolm.yates@gmail.com">chris.malcolm.yates@gmail.com</a></p>
<p>Skype: <span class="SpellE">christopher.m.yates</span></p>
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