The Seymour- Capilano Water Filtration Plant has a 30,000 ft Operations and Maintenance Centre. The Operations and Maintenance Centre is connected to the main filtration plant process areas (approximately 160,000 ft¦), which are not considered part of the LEED registration. The filtration plant process areas contain equipment, such as pumps, filters, blowers, UV disinfection equipment, etc. The enclosed spaces that contain process equipment have minimal freeze protection heating and condensation control ventilation. Only the Operations and Maintenance Centre is what might be considered "regularly occupied" (it contains offices, meeting rooms, labs, control rooms, etc.). We have included the energy required for heating and ventilating all of the areas (both filtration plant process and O&M Centre) in the energy analysis, for compliance with EA Prerequisite 2 and EA Credit 1. This was done for the following reasons: The entire facility is heated and cooled using a central geothermal system, including heat recovery from some of the process loads that is used to heat the total facility. Considering the integrated heating/ cooling system, splitting the energy consumption between the O&M Centre and the filtration plant process would be problematic and arbitrary. ASHRAE 90.1-1999, the energy performance standard referenced by LEED, applies to whole and contiguous facilities. As stated by the Standard, it applies to buildings that are enclosed and "afford shelter to persons, animals, or property." The standard applies to the envelope of a building, "provided that the enclosed spaces are 1. heated by a heating system whose output capacity is greater than or equal to 3.4 Btu/h-sf" (2.2.(a)). It also applies to "systems and equipment used in conjunction with buildings" for HVAC, service water heating, electrical power distribution and metering, motors and lighting. The CIR question is as follows: Since the filtration plant is only minimally heated and ventilated and since the heating and cooling energy for the operations building is derived from a common heating and cooling system that serves the total facilty, is it acceptable to include the energy consumption of the total facility in the energy model. The portion of the building with freeze protection only would likely be subject to the semi-heated space criteria in the envelope tables. Please provide specific energy modeling guidance for addressing the situation as described above, including the contribution of waste heat recovery from process equipment.
The total energy consumption of the facility should be included in the energy modeling results. This should include the energy for pumps, fans, blowers, filters and UV disinfection equipment (all process loads). The large volume of water in the facility should also be included, as it will have potentially significant impacts on overall energy consumption as well. Process energy should be fully included in the model so that the effect on the HVAC system is taken into account. The energy used directly for the process loads is then subject to post-processing (pumps, filters, UV disinfection, etc) as described in the LEED 2.1 Reference Guide beginning on page 145. The energy used by the HVAC system to account for the process energy is not factored out of the modeling results during the post-processing. The issue of waste energy recovery cannot be fully addressed without additional information. Most process waste energy recovery is not regulated by ASHRAE 90.1 and cannot be included in the proposed energy modeling results (non-regulated energy savings are eligible for an innovation credit). ASHRAE 90.1 regulates certain energy recovery options, such as water-side economizers, exhaust air energy recovery and condenser heat recovery. If you are using the large volume of water in the filtration plant as a heat source/sink for the heat pumps, this would be considered a regulated component and should be model the same for the proposed and budget buildings. Determine the type of energy recovery and whether it is a regulated or non-regulated component under 90.1. Note that the portion of the building with freeze protection only would likely be subject to the semi-heated space criteria in the ASHRAE 90.1 envelope tables. Applicable internationally.
Related Addenda (Corrections & Interpretations)