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I am forwarding my response to Larry Degelman in case there are others in the BLDG-SIM Group that might be interested. Varkie
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Larry
Thanks for your response. The percent glass of all building envelopes designed by architects in this office is greater than 50%. This has to do with exterior appearance, indoor working conditions, building construction costs, exterior maintenance costs and client satisfaction. So we always have to use the energy cost budget method to show code compliance. We have been doing this with DOE21.E. First analyze the building with Std90 criteria (50% glass with Table B properties, lighting densities, EERs, COPs, etc.) and then with the proposed building design using more efficient glass, lights, systems, equipment and renewable energy sources that will produce less than or equal to energy use and cost (using thermal storage, etc.) results. The attachment to our energy report includes the DOE2 output BDL for the base and the proposed designs as verification. I assume we can use this procedure to show energy savings from day-lighting controls under Building Envelope Trade-Off Options of Std90, Section 5.4 and Appendix-C. Can any other computer program, other than DOE2.1E, be used to show ECB compliance?
Based on the responses I received regarding day-lighting and LEED certification, I could cheat and locate the light sensor in a perimeter space in the DOE2 program run, so that it produces the highest lighting energy savings results. The single sensor location could represent a space with a perimeter depth of 50 ft or more and any floor area. I could also use a computer program that produces higher lighting energy savings than some other computer program. Title 24 code requires compliance using specific computer programs and there are instructions on using the programs so that everyone is on the same playing field. I think the location of the sensors and the geometry of the space (without going into the X,Y,Z coordinates of all the interior walls since there aren’t any in base speculative office building design) should be considered in energy codes.
Can 5 cfm per person of outdoor air be used for all types of commercial (non-industrial) spaces if the filtration system can produce the same indoor air quality as, say, 20 cfm per person for an office space? Does this qualify under “Energy Cost Budget” and “Energy & Atmosphere – Optimize Energy Performance”?
I apologize for sounding so ignorant? Since we have to use computer programs to show energy code compliance, the developers of the programs should adjust the program input and output to make it easier to use the programs to show code compliance. We were once asked to show Std90 compliance for an architecturally complex performing arts center using ComCheck-Plus. We had to create an equivalent rectangular box with 5 zones to do this. It could have been done with DOE2.1E using the procedure described above.
Should I send this message to the BLDG-SIM group? I don’t know who are out there and whether I am making a fool of myself
Varkie Thomas
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Just a side note of interest (with no judgment inferred):
ASHRAE/IESNA Standard 90.1-1999 no longer allows lighting control credits. Compliance is based on connected lighting power alone. With the 1989 Standard, credits could be taken for automatic controls/sensors and daylighting controls. (Inference about the dependability of lighting sensors/controls??? – I don’t know.)
Furthermore, VLT (Visible Light Transmittance) is not considered in the Prescriptive Envelope Option, but it is considered in the Envelope Trade-off Option, a la Chapter 5 (Sect. 5.3.2.4 and 5.4).
Regards, ===================================== Larry O. Degelman, P.E. larry@xxxxxxxxxxxx Prof. Emeritus of Architecture Ph./Fax: 1-979-696-2506 Texas A&M University =====================================
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Can day-lighting controls be considered for LEED certification under “Energy & Atmosphere – Optimize Energy Performance”? If so where should the light sensor be located in the space? Is there any energy code that allows credit for day-lighting controls? The DOE2 program allows two light sensors per space. Supposing the two sensors are located 5 ft and 10 ft from the window. Is the average daylight at these two points used in determining the reduction in artificial lighting?
The DOE2 program expects zones to have 6 surfaces defined with X,Y,Z coordinates and reflectance values for day-lighting analysis. Ignoring this produces warning messages but the results show a reduction in artificial lighting energy. For day-lighting analysis we only enter into DOE2 the X,Y coordinates of the window origin relative to the wall and also the wall and window dimensions. Can we assume that the energy savings results from the DOE2 program are on the safe side (the actual energy saved is more) when we use the program without all the surfaces and coordinates?
Are there any rules for day-lighting analysis for establishing energy savings and for comparing the results from different studies?
Varkie Thomas Skidmore, Owings & Merrill LLP Tel: (312) 360-4467 (direct) ==================You received this e-mail because you are subscribed to the BLDG-SIM@xxxxxxxx mailing list. To unsubscribe from this mailing list send a blank message to BLDG-SIM-UNSUBSCRIBE@xxxxxxxx ==================You received this e-mail because you are subscribed to the BLDG-SIM@xxxxxxxx mailing list. To unsubscribe from this mailing list send a blank message to BLDG-SIM-UNSUBSCRIBE@xxxxxxxx=====================================================You received this e-mail because you are subscribed to the BLDG-SIM@xxxxxxxx mailing list. To unsubscribe from this mailing list send a blank message to BLDG-SIM-UNSUBSCRIBE@xxxxxxxx |