Return Air in Car Storage?

[trueman]

I am working on a vehicle storage project in Manitoba and I would like to know if I can recirculate the air in a vehicle storage.

In my current system, I will have a makeup air unit with supply, exhaust fans and heat recovery system. The storage will be monitored with CO and NO2 sensors to change O/A and R/A. When any of the gas is above the set level, the system will run on 100% O/A.

I have tried to find a code or regulations whether it is acceptable to use return air or not but I couldn't find it. Can someone guide me on this.

 

[KesTheHammer]

Ashrae 62.1 section 6.5 says that you can use recirculated air, transfer air or outdoor air.

Having said that - it mentions a prescriptive path and a performance path - so if you read up on that section you should be good to go. I'd recommend also using CO2 sensors - even though CO is the more poisonous, CO2 is a byproduct of combustion as well and it kills you (by means of displacing oxygen)

Kestell Laurie
South Africa

 

[GT-EGR]

Not sure what the governing codes are in Manitoba, but in NY its the international mechanical code. If you go to chapter 4 ventilation (or whatever your equivalent chapter is) there are two locations that allow recirculation - in the front 403.2.1 section 3, which allows recirculation in a space that requires exhaust if it's only recirculated within that same space. Then later in the tables that define parking garage exhaust requirement (0.75 CFM/ft2) there is a note B which basically repeats this.

Further along in section 404 it gets specific about parking garages, which says if you monitor and control to CO and NO2 you are allowed to reduce ventilation/exhaust flow rates accordingly.

It's likely whichever your applicable mechanical code is, it has a similar section.

 

[joecampbell]

no you cant do that, your unit likely says this in its O&M. the gas code also does not allow it.

https://www.engineeredair.com/manuals/he-de

https://www.priceindustries.com/con...ect-fired-make-up-air-unit-manual-english.pdf

balancing issue, damper timing issues, failure state issue, interlock issues etc.

all to due a job that is better done by cp56 circ fans.