[Bldg-sim] Valance Units

[Christopher Schaffner]

Hi:

 

We've modeled several valance systems. Valance units are sometimes called
"passive chilled beams". They basically consist of a piece of fin-tube,
which is used for both heating and cooling, along with a drain pan to catch
condensate drips. While active chilled beams have an air supply, and could
be modeled as induction units, these do not have an air supply attached.
Typically, ventilation air is supplied through a separate dedicated outdoor
air system.

 

The easiest way to think of these is like a fan coil unit without the fan,
and that is exactly how we model them. In eQuest, set the system type to fan
coil, with chilled water and hot water coils, set the unit fan energy to
zero. One thing to watch for - valance units typically run at a low
waterside delta T (6 deg F on the cooling side)  - make sure you've
accounted for that or your pump energy will be too low.

 

We've found that for certain applications (like dormitories) valance systems
provide a high efficiency, low cost alternative, well worth considering.

 

Cheers,

 

Chris

 

 

________________________________________________

Christopher Schaffner, PE, LEEDR AP

USGBC LEED FacultyTM

 

The Green Engineer, LLP

Sustainable Design Consulting

50 Beharrell Street

Concord, MA 01742

t: 978-369-8978

m: 978-844-1464

chris at greenengineer.com

www.greenengineer.com <http://www.greenengineer.com/> 

 

Do something about Climate Change - Adopt the Architecture
<http://www.architecture2030.org/2030_challenge/index.html>  2030 Challenge!

 

 

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Vikram Sami
Sent: Tuesday, September 02, 2008 12:59 PM
To: Eric Youngson; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Valance Units

 

Tim,

 

I don't know if the induction unit with the 2-pipe option would be
appropriate for this, but it might be worth checking out. Personally I
haven't tried it yet, but it seems to be the most appropriate.

 

Eric, 

A valance unit is essentially an induction unit. From Harvard's website
below:

Valance systems are induction units that provide cooling or heating. In
cooling mode, chilled water is circulated through finned coils in the unit.
As warm air rises, it passes over the coils, is cooled, and sinks to the
floor, creating a constant convective loop. By eliminating the need for
forced air, the cooling load is reduced. In heating mode, hot water passes
through the finned tubes. As air passes over the coils, a layer of radiative
warmth is formed across the ceiling and is radiated back down into the
space. These units eliminate the need for an electric-driven fan to push
air, saving money and energy, while reducing draft and eliminating noise. 

 

 

Vikram Sami, LEED AP 
Direct Phone 404-253-1466 | Direct Fax 404-253-1366 

LORD, AECK & SARGENT ARCHITECTURE
1201 Peachtree Street NE, Suite 300, Atlanta, GA 30361 
Responsive Design . Technological Expertise . Exceptional Service 
Please visit our new website |  <file:///\\www.lordaecksargent.com\>
www.lordaecksargent.com

P Think GREEN before you print.

 

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Eric Youngson
Sent: Tuesday, September 02, 2008 12:16 PM
To: bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] Valance Units

 

Tim,

                What is a 'valance unit' system?

 

Thanks

 

Eric

 

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Howe, Timothy
Sent: Friday, August 29, 2008 12:00 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] Valance Units

 

Does anyone have any experience modeling a valance unit system?  I am
looking to developed an energy model for LEED submission.  Any suggestions,
thoughts, past experiences?

 

Thanks!

 

Tim.  

 

Timothy Howe, MS, LEEDR AP
Mechanical Engineer
Stantec

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