[Bldg-sim] eQuest 90.1 Window U Values

Vikram Sami VSami at lasarchitect.com
Fri May 23 05:34:33 PDT 2008


I'm curious - with the simplified glass model does eQUEST calculate the variable reflectance as a factor of the incident angle? (It was my impression that it did this only with the detailed option).
 
 
 
Vikram Sami, LEED AP
Direct Phone 404-253-1466 | Direct Fax 404-253-1366

LORD, AECK & SARGENT ARCHITECTURE
Responsive Design · Technological Expertise · Exceptional Service
www.lordaecksargent.com 

________________________________

From: bldg-sim-bounces at lists.onebuilding.org on behalf of Aulbach, John
Sent: Thu 5/22/2008 19:34
To: Josh Greenfield; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] eQuest 90.1 Window U Values



Under DOE2 Help, Dictionary/Glass-Type..


 


GLASS-CONDUCTANCE


The conductance of the glazing, excluding the outside air film coefficient. The conductance given in glass manufacturers' data sheets usually includes the outside air film resistance for a wind speed of 7.5 mph (summer) or 15 mph (winter). Table 10 can be used to obtain the corresponding value of GLASS-CONDUCTANCE. For example, if U(7.5 mph) = 0.64 Btu/ft2-hr-F, then GLASS-CONDUCTANCE = 0.79 (by interpolation). For U-values of different glazing types, see manufacturers' data sheets or the ASHRAE 1989 Handbook of Fundamentals, p. 27.16-17.

Table 10  
Correspondence between Glass manufacturers U-value and GLASS-CONDUCTANCE
(excluding outside air film) [all values are in Btu/ft2-hr-F (W/m2-K)]

U-Value
(including outside air film)

GLASS CONDUCTANCE

(7.5 mph wind speed)

(15 mph wind speed)

0.1 (0.57)

0.10 (0.57)

0.10 (0.57)

0.2 (1.14)

0.21 (1.19)

0.21 (1.19)

0.3 (1.70)

0.33 (1.87)

0.32 (1.82)

0.4 (2.27)

0.45 (2.56)

0.43 (2.44)

0.5 (2.84)

0.59 (3.35)

0.55 (3.12)

0.6 (3.41)

0.73 (4.14)

0.68 (3.86)

0.7 (3.97)

0.89 (5.05)

0.81 (4.60)

0.8 (4.54)

1.05 (5.96)

0.95 (5.39)

0.9 (5.11)

1.23 (6.98)

1.09 (6.19)

1.0 (5.68)

1.43(8.12)

1.24 (7.04)

1.1 (6.25)

1.64 (9.31)

1.40 (7.95)

1.2 (6.81)

1.87 (10.62)

1.57 (8.91)

1.3 (7.38)

2.13 (12.09)

1.74 (9.88)

 

Josh:

Convert your GLASS-CONDUCTANCE to come up with the appropriate U-Value.

See the attached for an ASHRAE window I did.

Why didn't you start with the ASHRAE run as Base, rather than the Proposed model first?

John R. Aulbach, PE, CEM
Project Manager
Nexant, Inc.
701 West Kimberly Ave., Suite 245
Placentia, CA 92870-6342 USA
Phone: 714-524-4402
Fax: 714-524-4407
email: jaulbach at nexant.com
 

 

 


________________________________

From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Josh Greenfield
Sent: Thursday, May 22, 2008 3:42 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] eQuest 90.1 Window U Values



I'm to the point in an Energy Model where I'm changing my 'Proposed Model' to my 'Baseline Model' and I'm having issues changing the window data.  For the ASHRAE 90.1 region, the Assembly U value needs to be set to 0.57 and the Assembly SHGC needs to be set to 0.39...where do I input these numbers??  The only window data values eQuest is letting me change is Glass Conductance, VLT and Emissivity...

 

 

Josh Greenfield, PE, LEED AP
Senior Associate
Primera Engineers, Ltd.
100 S. Wacker Drive, Suite 700
Chicago, IL 60606
312.606.0910 Main
312.242.6392 Direct
312.606.0415 Fax
jgreenfield at primerachicago.com
http://www.primerachicago.com <http://www.primerachicago.com/> 

Be Green...please consider the environment before printing this email.

 




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