Date
Inquiry

For our project, a high rise condominium tower, we are considering providing at move-in, full coverage, insulated, automated blinds on the interior of the building as part of the energy use reduction design strategy. These blinds will be built-in, non-optional, and fully automated with a manual override to allow occupants to override the automatic settings. The alternative would normally be owner provided blinds with a wide range of characteristics, but not likely to include the heavy, insulated blinds envisioned by this energy measure. We are considering sizing the design cooling and heating so that comfort can be maintained most effectively by using the blinds. Cooling reduction will probably include some venting between the fenestration and the interior blinds so that heat that enters the glazing does not stay in the space. Can we take credit for automatic shading by using the DOE2.2 shading inputs so the energy impacts are integrated with the rest of the model? ASHRAE 90.1-2004 Appendix G indicates that manual shades and blinds not be modeled in the baseline or the design. Automatic blinds or shades can be modeled for the design, and the baseline description does not say if these are to be modeled or not. For this energy measure, variations in model schedules between the design and baseline, with clearly stated assumptions and documentation, would be the appropriate way to model the difference in the operation of blinds between the design and baseline. Other inputs would account for differences in the design blinds and typical owner blinds including R-value, and shading coefficient. Please clarify whether we can capture the efficiency benefits of this strategy within our EAc1 model, and if so, the modeling requirements per the questions above and any other factors that might apply.

Ruling

The project team is seeking clarification regarding how to document the savings achieved from automated shading. ASHRAE 90.1-2004 Appendix G does allow credit in the Proposed Building model for automated shading devices, including automated blinds. No manual or automated window shading devices should be modeled in the Baseline Building model. If the energy software does not have the capability to model automated shading devices, the assumptions used for defining automated shading schedules should be clearly documented. Also, if the automated shading devices include a manual override for user control, the assumptions regarding percentage use of the automated controls should be clearly stated. Applicable Internationally.

Internationally Applicable
On
Campus Applicable
Off
Credits