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HomeMy WebLinkAboutFile Documents.216 S Monarch St.0055.2019 (65).ACBK aec Architectural Engineering Consultants, Inc. Mechanical, Electrical, & Lighting Design Services An Office with LEEDTTMM Accredited Professionals 40801 US Hwy 6 & 24, Suite 214, Eagle-Vail, CO 81620 Post Office Box 8489, Avon, CO 81620 phone: 970-748-8520 fax: 970-748-8521 email: stan@aec-vail.com web: www.aec-vail.com Gretchen Leary August 1, 2019 learygretchen@me.com Reference: Duemani Ventilation Review Dear Gretchen, At your request, we have undertaken a review of the existing kitchen exhaust and make up air systems for two kitchen spaces in the Katie Reed Building located at 301 East Hopkins in Aspen, Colorado. The spaces were previously operated as Rustique and are being reopened as Duemani. The information we have reviewed was taken from existing plans where available, and from field information provided by Ishmael at All Valley Maintenance Mechanical. We have also put together additional occupancy ventilation requirements as requested by the building department. It is our understanding that at this time the existing equipment is planned to be serviced and reused. It is the intent of this letter to state required ventilation rates and provide analysis of the estimated existing equipment capacities. Please note that this letter does not serve as verification of existing equipment capacities or as a construction document. Rustique Basement Kitchen Ventilation Requirements The Rustique basement kitchen has a single hood served with an independent exhaust fan on the roof. Make up air is provided to the space through a common system that also serves the main level Rustique kitchen. The current owner of Duemani plans to install only convection ovens below the existing hood. This equipment qualifies as a “light-duty cooking appliance” under the 2015 IMC and the exhaust and make up air rates calculated below are based upon this equipment classification. There is a chemical dishwasher planned for the kitchen space that will require 70 cfm of exhaust and make up air per the 2015 IMC. 08/19/2019 justinh Duemani Ventilation Review - DRAFT Page 2 of 4 August 1, 2019 Rustique Basement Kitchen Required Minimum Exhaust* Exhaust Trunk Size Make up Air Trunk Size to Space Make up Air Unit Make and Model Make up Air Unit Capacity** Exhaust Fan Make and Model Exhaust Fan Capacity 2,000 cfm 18x16 (1000 FPM) 34x21 (400 FPM) Reznor RPBL 1050 6,850 cfm @ 2” total static Industrial Air 226-018 Unknown *Exhaust calculated per the 2015 IMC for a 114” long wall-mounted canopy hood with light duty appliances - 200 cfm/lf for wall-mounted canopy hood. Includes 100 cfm for dishwasher **Make up air unit serves both the basement and main level Rustique kitchens – current balance is unknown. Performance values taken from existing drawings. Exhaust and make up air risers for the basement are adequately sized for the required hood exhaust and make up air rates. The makeup air unit has enough capacity for the basement – it may have enough capacity for both levels depending upon how much air is provided to the main level from the unit in the carport (see following section on makeup air). It is important to note that for the common make up air system to be compliant, both level kitchens must operate their exhaust fans and the common make up air unit concurrently. A test and balance would ensure that the airflow rates from the existing equipment are adequate. Rustique Basement Restaurant Space Ventilation Requirements The proposed basement dining areas is approximately 325 SF. Per the 2015 IMC, this space requires 0.18 cfm/sf of ventilation air in addition to 7.5 cfm/occupant (at 70 occupants/1000sf). This leads to a mechanical ventilation requirement of 230 cfm. This air will need to be provided by the common building ventilation system or from other means. There is a capped duct from the common ventilation system in the adjacent hallway that could be utilized so long as the equipment can provide the required ventilation. We would suggest that no less than a 9” diameter duct be tied in to at least a 9” diameter common duct and terminated in the restaurant space. This fresh air could be provided directly to the space or tied into a fan coil system. Fire dampers would be required for any duct penetrating a fire rating. Rustique Main Level Kitchen Ventilation Requirements The Rustique main level kitchen has a single hood served with an independent exhaust fan on the roof. Make up air is provided to the space through a common system that also serves the basement level Rustique kitchen. The Duemani main level kitchen will include the following equipment under the hood (provided by Gretchen on 7/30/19) – double-deck broiler, salamander, cheese melter, gas fryer, griddle range, gas range). There will be a chemical dishwasher that will require at least 70 cfm of exhaust air and make up air. Duemani Ventilation Review - DRAFT Page 3 of 4 August 1, 2019 Rustique Main Level Kitchen Exhaust Required Minimum Exhaust* Exhaust Trunk Size Exhaust Fan Make and Model Exhaust Fan Capacity 7,105 cfm 34x16 (1880 FPM) Industrial Air 226D022USAUGB Unknown – but assumed around 6850 cfm based upon existing drawings * Exhaust calculated per the 2015 IMC for a 211” long wall hood with heavy duty appliances – 400 cfm/lf. Includes 70 cfm for chemical dishwasher. The Exhaust trunk is adequately sized for required hood airflow; the exhaust fan capacity is unknown but assumed around 6850 cfm per the existing drawings. Exhaust fans typically have a range of operation – if more air is required it may be able to be rebalanced. Make up air is provided to the space through a common system that also serves the basement level Duemani kitchen. An additional make up air unit is located in the carport and provides untempered air to the space. Rustique Main Level Kitchen Make up Air Independent Make up Air Unit Trunk Size Independent Make up Air Unit Make and Model Independent Make up Air Unit Capacity Common Kitchen Make up Air Unit Trunk Size (to space) Common Kitchen Make up Air Unit Trunk Size (common) Common Kitchen Make up Air Unit Make and Model Common Kitchen Make up Air Unit Capacity* 24x24 (800 FPM @ 3,200 cfm**) Unknown Model – 5hp Dayton Motor Unknown, but assumed at 3,200 cfm** 36x24 (650 FPM @ 3905 cfm***) 48x21 (850 FPM @ 5905 cfm****) Reznor RPBL 1050 6850 cfm @ 2” ESP *Assumed capacity is taken from existing drawings ** Assumed capacity based upon existing duct size ***Assumed air balance from the common system. Calculated by subtracting assumed untempered air capacity from total make up air requirement. ****Assumed make up air requirement from common unit – sum of lower level and assumed upper level requirements The make up air supply trunks are adequately sized if balanced as shown on the table above. It is important to note that for the common make up air system to be compliant, both level kitchens must operate their exhaust fans and the common make up air unit concurrently. A test and balance would ensure that the airflow rates from the existing equipment are adequate. Rustique Main Level Restaurant Space Ventilation Requirements The proposed main dining areas is approximately 1267 SF. Per the 2015 IMC, this space requires 0.18 cfm/sf of ventilation air in addition to 7.5 cfm/occupant (at 70 occupants/1000sf). This leads to a mechanical ventilation requirement of 900 cfm. This air could be provided by the common building ventilation system or from other means. There is a capped duct from the common ventilation system near the existing kitchen hood that Duemani Ventilation Review - DRAFT Page 4 of 4 August 1, 2019 could be utilized so long as the equipment can provide the required ventilation We would suggest that no less than a 16x12 duct be tied in to at least a 16x12 diameter common duct and terminated into the restaurant space. This fresh air could be provided directly to the space or tied into a fan coil system. Alternatively, the space may be able to comply without mechanical ventilation if it can demonstrate compliance with Section 402 of the 2015 IMC. This section requires that the minimum openable area to the outdoors be at least 4% of the floor area (51 SF openable). Summary and Recommendations The current kitchen ventilation equipment is old but there is no reason to suspect that it is not functional. The exact exhaust and make up air capacities are unknown unless tested; however, the size of the existing kitchen equipment and ducting appears sufficient to meet the code ventilation rate requirements if serviced appropriately. It is important that the hoods and make up air unit be interlocked such that all equipment must run concurrently. If new equipment is desired, it must meet all applicable codes and local ordinances. Outside air at the rates described in the report must be provided to the restaurant areas to meet occupancy ventilation requirements. This requirement may be able to be met with operable windows and doors on the main level. Please let me know if you require any additional information. Best, Taylor Critchlow, PE