Trash/recycling chutes for Passive House multifamily

Hi Keihly,  I don't have  duct sealing detail but a reference which is relevant- the report below states that it's super important in compartmentalized multi-family buildings to keep the chute negative pressurized (sucking) and the trash rooms need to be even more negative pressurized - see the drawing and photo on p. 22 and section 3.4. Lsitburek, Joseph "Measure Guideline: Ventilation Guidance for Residential High Performance New Construction — Multifamily"
Building Science Press, 2005. https://www.buildingscience.com/sites/default/files/document/ba-1507_ventilation_guidance_final_measure_guideline.pdf

If it is multi story building, probably wants reverse stack effect too - cooler temperature inside the stack so the column of cool air drop and draw warmer air in from occupied space, with opening at the bottom of the chute.   If the chute has warmer temperature than occupied space, the normal stack effect will push air out to occupied space, especially the higher floors.  

Hi Keihly, In our mid-high rise multifamily buildings, we usually apply a painted air barrier product to our CMU trash chutes (DOW Defend Air), all around the outside of it, and if other walls share its corners, overalp on each side the wall min 3' both sides. The trash chute door itself is also fire rated (but ADA accessible) so fairly well sealed. Also, the trash room on each floor is fire rated (so pretty well sealed), and the door to it has exterior type weatherstripping.  And the trash room exhaust is tied to the corridor ERV.  Hope that helps! Thank you, Sara Bayer Magnusson Architecture and Planning

Hi Keilhy, Sorry for the delay in reply - we are working on a wood framed modular PH multifamily (6 stories) and can share some of our experience, although the key element of sequencing the installation of air barrier system components i'm not sure is resolved. Feel free to reach out with your email and maybe i can help with more details. For now, i can say the general strategy is pretty straight-forward: simply use airtight gaskets all around each chute door, and other than that it's a matter of making sure we are carefully assigning air tightness to the inner layer of gyp on the two-hour framed shaft wall assembly, and providing air-tight wrap (SAM) at floor assemblies. But again the trick is whether there is access to the interior of the chute to seal these connections, and whether the sequence is complicated by the modular construction. Katie