We are hoping to directly duct fresh air into a small utility room adjacent to an open room. In order to fully ventilate the adjacent space can we install transfer grills in doors/walls in order to facilitate fresh air movement between these 2 spaces in order to pass this prereq? Or must the air be directly ducted to the space requiring fresh air?
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Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
494 thumbs up
March 1, 2017 - 1:34 pm
We were successful transferring air from one room to the next when attempting this prerequisite.*
Be sure to "over ventilate" the room provided with outdoor to the amount needed to accommodate the other rooms being served by the transfer grilles.
*disclaimer: past reviews do not set precedence on future projects.
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
March 1, 2017 - 1:46 pm
You call it a "Utility Room". I cannot think of a utility room that does not have Class 3 air, based on Table 6-4. Class 3 air cannot be transferred to other spaces.
Based on your description, it seems as though it is a much better design choice to simply duct the air to a sidewall diffuser.
Dave Hubka
Practice Leader - SustainabilityEUA
LEEDuser Expert
494 thumbs up
March 1, 2017 - 2:03 pm
Good catch Andrew!
Only transfer if allowed per ASHRAE.
The rooms on our project in which we incorporated this strategy were allowed per ASHRAE to transfer air, and all the rooms had identical occupancies and schedules.
I also agree with Andrew's comment "duct to sidewall diffuser" may be a better design choice.
Alfonzo Collins
7 thumbs up
March 1, 2017 - 3:10 pm
the space being ventilated is a laundry room within a dwelling unit (class 1) and it would transfer air to a Bedroom/Living Room (Class 1).
David,
In your past experience LEED has accepted this method as long as we are providing enough cfm to properly ventilate the total square footage of the 2 adjoining spaces?
Andrew Mitchell, P.E.
PrincipalMitchell Gulledge Engineering, Inc.
LEEDuser Expert
126 thumbs up
March 1, 2017 - 4:32 pm
You will need to provide enough ventilation for the laundry, plus the amount for the other space. Use one of the two effectiveness factors at the bottom of Table 6-2 depending on where the return is located. That will help you get the right airflow to the space.