[Equest-users] Cooling Energy and Exhaust air heat recovery

[Bassam Yammine]

Hi Ahmed, not knowing the details of your system and model, but in
general by having an ERV, your system may not be able to take advantage
of the free cooling when outdoor air temperatures are below your return
air temperature and there is cooling demand. It seems from your numbers
that free cooling could be available for many days during the year.
During the cooling season, and unless it is bypassed, your ERV may  be
preheating cool before it enters the space.

 

Regards,

Bassam

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Ahmed
Azhari
Sent: Monday, May 17, 2010 8:21 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Cooling Energy and Exhaust air heat recovery

 

Hello Users, 

 

I have a packaged (Heating: Gas-Fired, Cooling: DX) air handling unit
with VAV boxes in the zones. The cooling coil control for the AHU is
Zone reset. I have noticed an odd behavior in the cooling side when I
model an exhaust air heat recovery as follow:

 

    

The cooling energy increase from 67.7MBTU to 132MBTU when I include 70%
exhaust air heat recovery which doesn't physically make sense to me.

 

When I change the cooling coil control to Outdoor air reset the results
change as follow:

 

 

 

The above scenario makes sense in a way that both the heating and
cooling energy decreased by incorporating exhaust air heat recovery.  

 

I appreciate any explanation on the strange behavior of scenario I

 

Best Regards, 

________________________________________________________________________
__

Ahmed Azhari, B.Eng., LEED(r) AP

Energy Analyst

 

Jain Sustainability Consultants Inc.

 

2260 Argentia Road, 2nd Floor

Mississauga, Ontario L5N 6H7, CANADA

Tel:  (905) 542 7211 Ext 234

Fax: (905) 542 7622

Email: aazhari at jainconsultants.com <mailto:aazhari at jainconsultants.com> 

Web: www.jainassoc.com <http://www.jainassoc.com/> 

 

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