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Garbage Room

Weil Member Posts: 23
I have been asked to install an exhaust system in a first floor garbage room in an office building located in Chicago.
The room is 8 feet by 12 feet with an 8 foot false ceiling with a 12 foot original ceiling. There is a window facing the alley and an entrance door to the hallway on the opposite end. The building is in a very strong negative pressure so when the door opens to this room the odors from the garage are disbursed through the offices. Not only do we have to overcome the negative air but also the wind outside that is famous in our windy city. Would this be a good scenario for an ERV? Or just a strong exhaust fan. any help is appreciated.


  • SWEI
    SWEI Member Posts: 7,356
    An ERV wheel would probably foul rather quickly there, and even the HX in an HRV would give me some concern (most are made of aluminum) from the fumes.

    I would probably suggest a variable-speed fan, modulated on constant pressure control, possibly with a boost switch tied to the building door.
  • Zman
    Zman Member Posts: 7,573
    Does the garbage room need to be heated?
    What is the source of the positive pressure? Is it mechanical?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Weil
    Weil Member Posts: 23
    The garbage room is not heated but maintains approximately 55 to 60 degrees now. Any suggestions on manufacturer and size of fan?
  • BillW
    BillW Member Posts: 198
    First of all, an erv only moves a small amount of air and the others are right about fouling the elements in the heat exchangers, and possibly corroding them as well. Decaying organic matter produces hydrogen sulphide which is corrosive and dangerous in high concentrations. If the building is under a strong negative pressure, that suggests an unbalanced ventilation system, which may not be working right, or may have been disabled in a misguided attempt to save energy. A variable speed fan may be of some help, but in this case source control is likely going to be more effective. Keep the room as clean as possible. Use sealed containers. Seal the inner door, and install an interlock so that the inside door can't be opened when the outer door is. Make sure that the ventilation air intake is away from the garbage area. Be sure to check out the ventilation system, though. Damper links break, actuators fail, and the uses for the building have likely changed since it was built. Keeping a building under negative pressure is a ticket to more problems in the future.
  • Abracadabra
    Abracadabra Member Posts: 1,948
    edited February 2016

    Bigger if you need one. Can get them up to 24"
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    I'd be inclined to investigate the high negative pressures first. In a properly controlled ventilation system, that kind of negative pressures shouldn't be a normal situation. Sounds like maybe someone shut off a make up/relief fan somewhere in the system. Having that much negative pressure is KILLING their heating bills, and causing major discomfort issues.

    Look at the HVAC "system" as a whole, and not just focus in on the odor issues. Something has changed....


    There was an error rendering this rich post.

  • Weil
    Weil Member Posts: 23
    Thank you gentleman, I have tried to address the negative air issue but they don't seem to want to spend the money. Even though they are throwing money out the window. Appreciate the insight.