Appendix G additional system types

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I modeled a residence hall on a college campus using ASHRAE 90.1-2004
Appendix G System Type 1 - PTAC, with a system per zone. I received the
following comment from the LEED Reviewer:

"Section G3.1.1 states that additional system type(s) should be used for
the non-residential space types (including corridors, classrooms,
lounges, public living rooms, etc.). The notes at the end of Table
G3.1.1A identify which spaces are considered residential."

The referenced note states, "Residential space types include guest
rooms, living quarters, private living space, and sleeping quarters.
Other building and space types are considered nonresidential."

There is 4,000 ft2 of classroom and conference room space. If I include
corridors, common living rooms, lobby, mech/elec/data, stairwells,
storage, common bathrooms and laundry, I would exceed the 20,000 ft2
threshold condition of the G3.1.1 exception.

The example given in the User's Manuals as a qualifying exception is "a
residential tower with retail and restaurants at the base".

Does anyone think this necessitates additional system types? (System 3
presumably, one per zone.)

Thanks,

Bill

Bishop, Bill2's picture
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I do think this necessitates one or more additional system types. As for what spaces go on it, I am inclined to say everything but the dorm rooms themselves. A possible exception could be there depending on how you are conditioning, ventilating, and exhausting the corridors and common bathrooms. As for what system type(s), that depends on the area and the number of floors. If you have spaces on four or more floors on a second system type, you probably triggered VAV (system 5 or 6). G3.1.1b might keep some of your spaces (e.g. laundry, mech/elec/data) as CAV (system 3 or 4) based on the peak load or hour criteria.

Good luck,
Paul Riemer, PE, LEED AP

Paul Riemer's picture
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Joined: 2011-09-30
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Hi Bill,

Assuming you are treating your building as predominantly residential,
then include a second nonresidential system type if nonresidential
spaces total more than 20,000SF.

Assuming you are treating your building as predominantly nonresidential,
then include a second residential system type if residential spaces
total more than 20,000SF.

"Residential spaces" are exclusively "guest rooms, living quarters,
private living space, and sleeping quarters" per the notes under the
system type table. Laundry rooms and similar don't count, if the
reviewer is taking a very literal interpretation.

This is one of those cases where you could possibly support either
course of action... if the numbers work out.

NICK CATON, P.E.

Nick-Caton's picture
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Joined: 2011-09-30
Reputation: 605

I agree with the approach that corridors and bathrooms in the dorm portion
will be operating continuously, and wouldn?t necessarily share a
schedule/system with the classrooms and supporting areas.

I?d consider corridors and stairwells that support the dorms to be part of
that usage, and spaces that support the classrooms and non-residential usage
to be allocated there, going through the system selection table on their
own.

David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP

*From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Paul Riemer
*Sent:* Friday, June 17, 2011 9:57 AM
*To:* 'Bishop, Bill'; bldg-sim at lists.onebuilding.org
*Subject:* Re: [Bldg-sim] Appendix G additional system types

I do think this necessitates one or more additional system types. As for
what spaces go on it, I am inclined to say everything but the dorm rooms
themselves. A possible exception could be there depending on how you are
conditioning, ventilating, and exhausting the corridors and common
bathrooms. As for what system type(s), that depends on the area and the
number of floors. If you have spaces on four or more floors on a second
system type, you probably triggered VAV (system 5 or 6). G3.1.1b might keep
some of your spaces (e.g. laundry, mech/elec/data) as CAV (system 3 or 4)
based on the peak load or hour criteria.

Good luck,

*Paul Riemer, PE, LEED AP*

*From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Bishop, Bill
*Sent:* Friday, June 17, 2011 9:29 AM
*To:* bldg-sim at lists.onebuilding.org
*Subject:* [Bldg-sim] Appendix G additional system types

I modeled a residence hall on a college campus using ASHRAE 90.1-2004
Appendix G System Type 1 ? PTAC, with a system per zone. I received the
following comment from the LEED Reviewer:

?Section G3.1.1 states that additional system type(s) should be used for the
non-residential space types (including corridors, classrooms, lounges,
public living rooms, etc.). The notes at the end of Table G3.1.1A identify
which spaces are considered residential.?

The referenced note states, ?Residential space types include guest rooms,
living quarters, private living space, and sleeping quarters. Other building
and space types are considered nonresidential.?

There is 4,000 ft2 of classroom and conference room space. If I include
corridors, common living rooms, lobby, mech/elec/data, stairwells, storage,
common bathrooms and laundry, I would exceed the 20,000 ft2 threshold
condition of the G3.1.1 exception.

The example given in the User?s Manuals as a qualifying exception is ?a
residential tower with retail and restaurants at the base?.

Does anyone think this necessitates additional system types? (System 3
presumably, one per zone.)

Thanks,

Bill

David S Eldridge's picture
Joined: 2011-09-30
Reputation: 2000