All other regularly occupied spaces, besides the residential apartments, have been entered correctly using the thermal comfort tool. These spaces are mechanically ventilated. However, we received the following review comment:
"Please ensure all space types, namely the residential units, in the project building have been addressed in Table IEQc7.1-1 and that supporting documentation demonstrating compliance with ASHRAE Standard 55 has been provided."
This is my first time working on this credit and I am unaware how to demonstrate natural ventilation in the apartments using the thermal comfort tool. Is this possible? The apartments only have exhaust only spaces, such as the kitchen and bathroom.
thanks!
Julia Weatherby
PresidentWeatherby Design & Co. Engineers
94 thumbs up
July 16, 2014 - 6:43 pm
Hi, Courtney-
I'm not sure why natural vs. mechanical ventilation would matter for the Thermal Comfort Design credit. The thermal comfort tool deals with temperature, humidity, etc. as well as the activity level and amount of clothing worn by the occupants. I believe you should be able to apply the thermal comfort tool in residential spaces without much difference from the way it is applied to your mechanically ventilated spaces. This credit has to do with mechanical conditioning, not mechanical ventilation. As long as you have heating and air conditioning in the residential units, it seems likely to me that you would be able to comply with the Thermal Comfort Design credit.
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
July 17, 2014 - 9:02 am
I agree with Julia. The thermal standard is not coupled to the ventilation standard.
Courtney Royal
Sr. Sustainability ConsultantTaitem Engineering
50 thumbs up
July 18, 2014 - 11:10 am
Thank you both, Julia and Scott. This is very helpful. The reason I was thinking ventilation had something to do with credit documentation is because the credit form asks you to select if the building is mechanically or naturally ventilated so I assumed it needed to be accounted for. Why does this form request this information then?
Thanks!
Julia Weatherby
PresidentWeatherby Design & Co. Engineers
94 thumbs up
July 18, 2014 - 11:45 am
That's a good question. I think the language in the v. 2009 reference guide is a bit muddled about the difference between natural ventilation and natural conditioning. There is a reference to Section 5.3 of ASHRAE 55-2004, but that section deals with natural conditioning, not natural ventilation. I think as long as you have mechanical *conditioning*, that for version 2009 the natural vs. mechanical ventilation should not matter. This is especially true in a residence where the required amounts of ventilation are tiny. I suppose a reviewer might question the impact on comfort if one is depending on natural ventilation for a high occupancy space, but that would be more applicable in a non-residential usage and also may come into play more in LEED v4 from what I have heard.