Hi,
We have a library project and we received the review comments from USGBC and requested to provide the following:
1. A "detailed narrative" describing the thermal comfort design criteria for the project which includes specific information for each thermal comfort zone.
2. Explanation of any special conditions or circumstances that require zones to exceed the ASHRAE ranges.
3. Confirm the compliance approach used (graphical or computer based) to assess occupant satisfaction of all bldg. occupants.
4. If using graphical method, provide documentation. Otherwise, resubmit the credit form using the approach outlined in section 5.2.1.2 computer model method for general indoor application.
Can someone help me on how can i provide those narrative (eg. sample)?
We don't have software that could provide graphical method, what does it mean computer based?
Any input and/or assistance on this is highly appreciated.
thanks,
Susan
Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
963 thumbs up
November 27, 2012 - 5:21 pm
"Graphical method" means the chart shown in ASHRAE-55 for the acceptable range of temperature and humidity. (Figure 5.2.1.1)
Provide a narrative explaining that the expected activity levels fall between 1.0 met and 1.3 met, that clothing insulation is expected to be between 0.5 clo and 1.0 clo, and that air speed is designed to be less than 40 ft/min in the occupied zone. (These are the criteria required to use the graphical method, and would be typical in a library). Then demonstrate that temperature and humidity is typically held within the range indicated in Figure 5.2.1.1 during occupied hours.
Section 5.2.1.1 of ASHRAE 55 has all the details.
susan eguia
LEED Coordinator/Construction Administrator/Business DevelopmentBuilding Solutions Group, Inc.
59 thumbs up
November 27, 2012 - 7:39 pm
Christopher,
Thanks for respond. Follow-up question, please:
1. Does it mean, we need to provide the PMV graph or we can use the thermal comfort tool that you've shared as our support document to satisfy ASHRAE 55 section 5.2.1.1?
2. Is there a formula for air speed? How can i get the less than 40 ft/min.
3. I'm using V4.0 credit form, it's not indicated the MET and CLO values. The only info available is space design parameters and local discomfort effect.
thanks,
susan
Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
963 thumbs up
November 27, 2012 - 8:53 pm
1. I think you could use either tool. You could also xerox the graph in ASHRAE and draw a dot showing your design conditions.
2. Air speed is based on diffuser selections. 40 FPM is pretty high. Typically, the diffuser manufacturers data will show data on the "throw"; that is, the limits of different velocities in relation to the diffuser, based on different air flow rates. Ask your HVAC engineer. Unless you are specifically trying to get a cooling effect by using higher air speeds you probably are much less than 40 fpm
3. So put in the space design parameters. Make sure the temperature & humidity you list falls within the comfort zone. Make sure the air speed is less than 40 FPM. Make sure you can back up these claims. For local discomfort effects, check all the "not likely" boxes.
susan eguia
LEED Coordinator/Construction Administrator/Business DevelopmentBuilding Solutions Group, Inc.
59 thumbs up
December 11, 2012 - 6:34 pm
Hi Christopher,
Sorry to bother you.
Just want to make sure that i understand what you're saying. " I can copy the graph from ASHRAE 5.2.1.1 and draw a dot showing my design conditions". What values should i reflect here; the operative and design humidity (cooling and heating) of my space design parameters? Do i need to delete other mark-ups from the graph i.e. Clo, database from ISO etc.)
How about my local discomfort? I think the reviewer want me to confirm the approach used - graphical or computer based aside from check all the boxes.
thanks again.
Susan
Christopher Schaffner
CEO & FounderThe Green Engineer
LEEDuser Expert
963 thumbs up
December 13, 2012 - 5:12 pm
"What values should i reflect here; the operative and design humidity (cooling and heating) of my space design parameters?" - Yes
"Do i need to delete other mark-ups from the graph i.e. Clo, database from ISO etc.) " - if it makes it clearer, sure.
"How about my local discomfort? " - not sure what you mean. Make sure the air speed is less than 40 FPM.
" I think the reviewer want me to confirm the approach used - graphical or computer based aside from check all the boxes." - this is the graphical method