[Equest-users] Heat Recovery

[Bishop, Bill]

Bill,

There should always be at least a slight increase in fan energy when you
add heat recovery to a system, leaving everything else equal (duct size,
cabinet size, airflow rate etc.). By default, eQUEST adds either 1.5" or
1.0" static pressure (depending on the ERV device type you select) to
both the make-up and exhaust air streams. The extra static is added to
the system supply and return fans, unless you create separate
"self-contained" ERV-FANS under the system Outdoor Air -> Heat Recovery
2 tab. If you don't have separate fans in the ERV/HRV, and you know what
the total static pressure of the system is with heat recovery included,
you can enter the system SUPPLY-STATIC under Fans -> Fan Power and
Control, and zero out the ERV-OA-STATIC and ERV-EXH-STATIC.

If the heat recovery system is not designed yet and you are running
what-if scenarios, try different control strategies under system Outdoor
Air -> Heat Recovery 1, ERV-RUN-CTRL and ERV-RECOVER-MODE. Optimizing
the control strategy will help you find the best balance between fan
energy penalty, cooling energy savings/penalty and heating energy
savings.

Regards,
Bill


-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bill
Lafley
Sent: Saturday, July 30, 2011 1:34 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Heat Recovery

Hello,

When I add heat recovery to my proposed model the natural gas usage 
drops significantly but the vent fan electrical usage skyrockets to 
almost 6 times the base vent fan usage without heat recovery.  I 
searched the archives and tried adjusting down the in W.G. but it does 
not seem to reduce it.  Is there something else I should be looking at?

Thanks,

<http://www.cetonline.org>

Bill Lafley <mailto:blafley at cetonline.org> | Energy Analyst
Center for EcoTechnology
<http://www.cetonline.org>
<http://www.cetonline.org/Mailist/VR_Signup.php>


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