ID#2416 made on
EAc1 - Optimize energy performance
LEED BD+C: New Construction, LEED BD+C: Schools, LEED ID+C: Commercial Interiors, LEED BD+C: Core and Shell, LEED O+M: Existing Buildings
Our project is a newly constructed, 825,751 square foot automotive manufacturing facility in the midwest. The ventilation requirements for our facility, as set forth by ASHRAE 62.1, Section 2.2 states...
Our project is a newly constructed, 825,751 square foot automotive manufacturing facility in the midwest. The ventilation requirements for our facility, as set forth by ASHRAE 62.1, Section 2.2 states: "Additional requirements for laboratory, industrial, and other spaces may be dictated by workplace and other standards,.". Industrial facilities in this location fall under the requirements of the Michigan Occupational Safety and Health Administration (MIOSHA). Per MIOSHA's, health standards ("Part 520. Ventilation Control"), R325.52007 Exhaust ventilation systems, Rule 7 states : "The minimum rate of exhaust ventilation for places of manufacturing, processing, assembling, maintenance and repair, or storage of material shall be 1 cubic foot of air per minute per square foot of floor area. This amount of exhaust ventilation may be provided by local exhaust, general exhaust, or both. The director may permit a variance if contaminant control is accomplished at a lesser rate of ventilation." MIOSHA has stated that an allowable level of contaminant control for dust/mist particulate would be 5 mg/cubic meter. In an attempt to save ongoing heating, cooling and ventilation expenses, the Owner chose to design the new facility in an innovative manner that could attain contaminant control at a much lesser ventilation rate than the default 1 CFM/SF that is set forth by MIOSHA and used by other automotive manufacturing facilities. The manufacturing facility has set a target of 0.5 mg/cubic meter, significantly lower than the MIOSHA required level of contaminant control. In order to reach this high level of contaminant control, they implemented the following innovative approaches: 1 - For the machining and grinding processes, enclosures were constructed and oil mist/dust collection systems were implemented with HEPA filtration. 2 - For the parts washers, enclosures were constructed and local exhaust ventilation systems were designed to capture contaminants at the source. 3 - For processes using hazardous materials, local exhaust ventilation systems were designed to capture contaminants at the source. 4 - "Dry floor guarding" systems have been implemented in the machine tool enclosures in order to minimize any escaping mist from the process. 5 - Micro-bacteria resistant coolants are used in the plant and biocides and utilized and monitored in order to control the bacterial counts in such systems. These control measures are over and above what is done in a typical, newly constructed manufacturing plant. With these control measures being utilized, extensive testing was done through the manufacturing facility to ensure that MIOSHA (and the much more stringent company requirements) exposure limits were being met. During the testing, the facility was ventilated at a rate of 0.21 CFM per square foot. At this ventilation rate, the facility was far below the company's target exposure limits, never measuring higher than a 0.13 mg/cubic meter exposure level. The Owner operates their facility at a ventilation rate of 0.5 CFM per square foot. This adds another level of safety factor to the building design. We are proposing that we run the energy model, in both the baseline and proposed case, with a ventilation rate of 1.0 CFM per square foot. We then intend to use the Exceptional Calculation Methodology of ASHRAE 90.1 to quantify our energy cost savings by lowering the ventilation rate. We intend to re-run our "proposed" model with 0.5 CFM per square foot to determine the cost savings for this exceptional calculation.
The applicant is proposing that energy savings due to ventilation load reduction resulting from several pollutant source control measures be approved as an Exceptional Calculation Methodology (ECM). The use of baseline and proposed case exhaust rates above those required by ASHRAE 62.1-2004 Section 6.2.8 are acceptable per ASHRAE 62.1-2004 Section 2.2 and the requirements specified by Michigan Occupational Health and Safety Administration (MIOSHA). Since it is a non-regulated process load, the project team must establish reasonable assumptions under full operational conditions for the baseline and proposed case. It appears that the project team has put a substantial effort into identifying and controlling sources of indoor pollutants and in an effort to reduce ventilation loads. Additionally, testing has been conducted to verify that the particulate concentrations are well below MIOSHA requirements even at reduced ventilation rates. The proposed documentation of energy savings from ventilation load reductions in the proposed case may be documented as an ECM. Please note that the favorable ruling of this CIR does not guarantee credit acceptance during a review. The project team should provide sufficient documentation to support the proposed ECM. Also note that the ruling is specifically applicable to the project in question due to the substantial efforts made to control sources of indoor air contamination at the source and testing for compliance; the ruling is not necessarily applicable to projects with different circumstances.
Related Addenda (Corrections & Interpretations)