I am in the process of preparing the documentation for this credit but have a few a few questions regarding ASHRAE 6.1.1 Documentation and associated calculations. Apologies in advance for the lengthy query. 1. Does the psychrometric chart need to be submitted despite providing PMV/PPD result from ASHRAE thermal comfort tool? 2. If so, where can we obtain a psychrometric chart suitable for LEED Upload? 3. Do we have to calculate the thermal comfort for each and every zone in the project? Or can we provide the calculations for the representative zones by space usage type? For example, on our project, we have several types of offices, retail spaces and hotel spaces as well. However there are over 500 individual zones on the project. So can we apply the calculation for each "type of zone" rather than for each individual zone? 4. How to demonstrate design compliance in accordance with ASHRAE Section 6.1.1 documentation? Should we write a narrative in accordance with ASHRAE Section 6.1.1 documentation? especially, Otherwise I am not sure how to demonstrate and meet the building envelope part according to ASHRAE 55-2004. 5. Finally, is the indoor air speed equal to air speed from diffuser of VAV system?

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Christopher Schaffner

CEO & Founder

The Green Engineer

LEEDuser Expert

630 thumbs up

Tue, 07/09/2013 - 14:54

1) The psych chart is not mandatory, but you should provide information about all seasons and part load conditions. This could be a narrative. 2) there are many psych chart tools available - google 'psych chart'. 3) not each zone, but each space type. 4) provide a narrative 5) indoor air speed depends on diffuser selection. The air speed we care about is the air speed an occupant will feel, not the diffuser discharge velocity. Look at the throw characteristics of the diffuser. Most diffuser data sheets show the throw at different velocities - i.e. the distance from the diffuser at which that velocity exists. For most situations you want the velocity at the occupant to be 40 FPM or less.

Sangmin An

Building Energy Simulation Analyst

SGS

LEEDuser Basic Member

2 thumbs up

Tue, 07/09/2013 - 01:21

Thank you very much for your help. It is greatly helpful for me in performing this project and completing this credit.

Maya Karkour

EcoConsulting

LEEDuser Basic Member

549 thumbs up

Fri, 08/22/2014 - 07:34

Hi Christopher, Following up on question (5) above: a) How can I convert the air velocity at the diffuser outlet to the air velocity reaching the occupant, knowing that an open plan office will have several desks and some occupants will be closer to the diffuser than others? Do I take average location in the middle of the room? b) The diffusers for my project are located just below the ceiling level (around 9 feet above floor) whereas I need to report the air speed at the seating level of occupants (3 feet above floor). Do you think diffuser manufacturers will have these values? c) The Mechanical Engineer confirmed that this is a typical project with a typical HVAC design strategy. Can I assume that the air speed is 40 feet per minute (as a default value) without further documentation to the USGBC, given that they don't ask for any documentation?

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