Rating System

LEED BD+C: New Construction, LEED BD+C: New Construction, LEED BD+C: Schools, LEED BD+C: Schools, LEED BD+C: Core and Shell

Rating System Version

v2 - LEED 2.2, v3 - LEED 2009, v2 - Schools 2007, v3 - LEED 2009, v3 - LEED 2009

Inquiry

Our question deals with selecting the most appropriate space usage and HVAC baseline equipment for non typical rooms for EAc1. The project involves the construction of an airplane hangar facility with a gross area of 26,000 square feet and 2 stories high. The building is comprised of office spaces, metal shops, mechanical room, electrical room, foam room (for fire protection equipment), telecom room and a hangar(with an area of 12200 square feet). A gas fired boiler will provide heating and chiller will provide cooling. The design building systems are as follows: -the office spaces are served by a VAV system with reheat coils -the metal shops are served by constant volume air handling units; the metal shops also have exhaust hoods with dedicated exhaust fans that are interlocked with dedicated 100% make-up air units equipped only with gas fired heat exchanger. -the hangar is heated by an under floor heating system and cooled by 2 rooftop units with direct expansion coils and each sized for half of the total load; the rooftop units are equipped with a gas fired heat exchanger that serves as a backup for the under floor heating system; the hangar will be used as a retrofitting space, meaning that an airplane will be brought in and equipped with various equipment; only attachment/detachment of equipment is performed in the hangar; actual work(preparation, manufacturing) on the equipment is performed in the metal shop rooms adjacent to the hangar. -the foam room is ventilated via a dedicated exhaust fan and outside air intake louver; heating is provided by unit heaters; no cooling provided -the mechanical room is ventilated by a dedicated exhaust fan and outside air intake louver; heating is provided by unit heaters; no cooling provided -the electrical room is ventilated by a dedicated exhaust fan and heated by a unit heater; no cooling provided -the telecom room is cooled and heated by a dedicated heat pump split system -stairways are heated by finned tube radiators; no cooling provided -the elevator machine room is cooled by a fan coil unit; no heating provided -janitors room and toilets are provided with a dedicated exhaust system; no cooling or heating is provided; -mixed shower/toilet rooms are provided with a heating and cooling system through a VAV box. For EAc1 we will use ASHRAE 90.1 Performance Rating Method make the following assumptions: 1. Baseline HVAC System: System 3 PSZ-AC 2. Space usage classification for the hangar is: "wood/metal shop" for ventilation and "workshop" for lighting 3. The dedicated 100% outside air make-up air units that serve the metal shops and are interlocked with the exhaust fans will be included in "process loads" category together with the exhaust fans. 4. Process loads generated by the metal shop rooms and hangar equipment will be the same in both baseline and proposed building performance. We have the following questions: 1. In the baseline building performance: should the janitors rooms, toilets, mechanical, foam and electrical rooms and stairways be served, individually, by system 3? 2. If the telecom room will be served by a heat pump system can the baseline building system be system 4 PSZ-HP (only for this room)? 3. Is our space usage classification for the hangar correct? Due to the fact that the metal shop work is performed not inside the hangar area, can the hangar room be classified as a "warehouse"(for ventilation purposes only)? 4. If our space usage classification for the hangar area is incorrect, please recommend one, for both lighting and ventilation. 5. Are our assumptions correct?