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  1. #1
    Join Date
    Aug 2006
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    Make-up air, multiple EFs, & Air handler

    This what I have, Mcquay RTU with preheat and heating coil for MA, there is a return so it's not 100% An exhaust fan over the cooking island, and one for the dishwasher in this zone. A front line with its exhaust fan, the McQuay RTU serves the dining area, cashier, and front line which is cafeteria style, in this zone. This RTU has preheat coil, cooling coil, and reheat coil, Both unit Coils are heating water and cooling glycol. If the freeze stat. or smoke detector trip in either RTU, whole system is shut down. What is the proper sequence operation for this set up, should there be an interlock so if the EF isn't running the RTU(s) shouldn't run? There appears to be two separate zones even though they prop doors open. I don't have to worry about balancing the system, as I put a stop/disclaimer in doing the work without rebalancing being done after, to CMA. Also there is a hood washing system that doesn't work. Ansul systems that do work.

  2. #2
    Join Date
    Sep 2006
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    Make Up Air

    Normally there's an interlock to bring in outside air when the exhaust fans are running. Otherwise the kitchen area would operate in a very high negative pressure. Starting the exhaust fans should start the make-up air unit(s). If the make up air unit(s) flow switch doesn't make within a certain amount of time or the make-up air unit(s) fail, then the exhaust fans are shut down.
    Law Of The Thermostat: He who has the thermostat wins!!!!!

  3. #3
    Join Date
    Mar 2007
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    Outside Air Damper

    As the exhaust fans come on the outside air damper should open. If you have multiple exhaust fans then a differential pressure sensor should be installed and the outside air damper should have a 0 - 10v actuator. This way you will always be maintaining the correct space pressure regardless of how dirty or clean the filters are etc...

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