[Equest-users] Control of Energy Recovery System in the Baseline Building on ASHRAE 90.1-2010 Simulated

[Fred Betz]

Konstantina,

It’s not a contradiction as your wheel is only seeing your outdoor flow whereas an economizer would see more air flow.

If you’re 30% outside air at 10,000 cfm you have 3,000 cfm bypassing the wheel. The other 7,000 cfm are being returned and never see the wheel.

If you had an economizer you might get up to twice that flow rate when it’s 65F-75F depending on your location’s economizer requirements.

Yes, it’s economizing, a little but not enough to meet the full requirements of an air-side economizer. The intent here is primarily to avoid the pressure drop of the wheel while not recovering heat.

Hope that makes sense.

Dig into the hourly flow rates and loads to determine that’s working properly as the controls can get wonky.

Good luck.

Fred

Fred Betz  PhD, LEED® AP BD+C
Building Performance
AEI | AFFILIATED ENGINEERS, INC.
5802 Research Park Boulevard | Madison, WI  53719

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From: Konstantina Kalliakoudi <kalliakoudi.k at gmail.com>
Sent: Wednesday, February 5, 2020 3:55 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Control of Energy Recovery System in the Baseline Building on ASHRAE 90.1-2010 Simulated

Hello to all equest -users,
I am trying to model  my  Baseline building based on ASHRAE 90.1-2010.
In my case:

1.       In my case based on paragraph G3.1.2.11 and in accordance with Section 6.5.6.1 due to the climate zone and the %outdoor air at full design airflow rate “my baseline building” require Heat Recovery System.

2.       Due to the climate Zone from Table G3.1.2.6A  an Economizer is not required.
My question is about the control of the heat exchanger in the baseline building. In paragraph 6.5.6.1 is mentioned: “Provisions shall be made to bypass or control the energy recovery system to permit air economizer operation as required by 6.5.1.1”.
The tables of 6.5.1.1, Table 6.5.1.1A and B mention about control of Economizer.
Also is in the baseline building required an economizer required or not? I mean, Table G3.1.2.6A   and tables  6.5.1.1A and B seems to be in contradiction.
I have modeled this in equest as following: What do you think;
[image.png]



[image.png]

Thank you

Konstantina Kalliakoudi

Konstantina Kalliakoudi
Mechanical Engineer,M.Sc.,

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