Integrated HVAC for Building & Greenhouse This CIR proposes an innovation design credit for a design to integrate the HVAC system between the greenhouse and the main building of the new Pacific Garden Mission (PGM) facility in Chicago. The intent of the proposed design innovation is to: 1) use the greenhouse vegetation to help improve the air quality in parts of the main building; 2) pass the building exhaust air through the greenhouse to provide carbon dioxide enriched air to help in plant growth in the greenhouse. The new PGM facility includes a men\'s and a women\'s greenhouse attached to the south wall of the facility. The design calls for an HVAC system that can operate in the following three modes modes: 1)Exhaust building air from the adjacent 1st floor rooms through the greenhouse to help heat and cool the greenhouse, keep it positively pressurized to avoid infiltration. Our preliminary energy modeling indicates that this mode of operation will result in annual avoided heating costs of at least $2,500 or over 1% of the projected energy costs for the current building design. Exhausting building air through the greenhouses will promote plant growth by supplying greenhouse with CO2-enriched building exhaust air. 2)Draw air through the greenhouse so that it can be tempered and supply part of the make-up air required for the dining/kitchen area. 3)Divert the air from the adjacent rooms through the greenhouse to clean, humidify it, and enrich it with oxygen before it returns back to the building. Our approach is to include the energy saving aspects of these design features in the energy model of the building that has been prepared for EA Credit 1 Optimized Energy Performance. Therefore, our proposed Innovation Design Credit is for the environmental benefits of this design that integrates the HVAC systems of the greenhouse and main building. We look forward to the USGBC\'s guidance on this exciting potential innovation in design.
It is not clear that circulating air through the greenhouse will improve IEQ. It is equally as likely that the greenhouse could introduce allergens. Some of the supposed benefits (humidity control) are already addressed by existing credits. To better understand the air quality benefits of exhausting building air into the greenhouse, and more importantly, drawing recirculated air through the greenhouse for use in the occupied building, the team would have to provide additional evidence to earn an Innovation in Design Credit. Modes 1 and 2 above will provide energy savings and should be included in EAc1. Mode 3 would require evidence, such as monitoring, demonstrating that the air returning to the building is cleaner and enriched. As to humidification of the air, humidity sensors, awarded under EQc7.2, would be required to substantiate the claim and ensure that the air does not have too high of a moisture content. Applicable Internationally.