Many common software questions are answered in the categories below. If you can’t find a response for yours, try checking our User Forum, or, contact HelpDesk for direct assistance

MarketManager » Envelope
Q: How do I model a door that is open for one hour per day?


You want to make sure that you account for loads due to infiltration. Unfortunately, I cannot think of any way to trick MarketManager into scheduling solar transmission or transmission, but since it is just an hour, it should be ok.

If you have a single Zone project, then follow steps 1 - 10. If you have a multizone project, then you should replace the Small School Templates Zone with your affected Zone, and then follow steps 1 - 10. Then after finishing those steps, drag the ZONE back into your project, replacing its previous incarnation.

What you are going to do is add a Makeup Air FAN to the ZONE, with a schedule of just one hour per day. But to determine the CFM for the Makeup Air FAN, you will need to model the open door first and find out the resulting infiltration.

  1. Model the door as a DOOR.

  2. In the DOOR | Detail Data Form, enter 144 in2/ft2 for specific leakage area.

  3. In the BUILDING | Air Infil Data Form, check "No" for "Use Design AI for Monthly AI?". This tells MarketManager to use the LBNL Infiltration Model to calculate the hourly infiltration, rather than using your estimates at the bottom of the ZONE Data Form.

  4. Note the monthly ACH values in the BUILDING | Air Infil Data Form, and enter in higher values for Design ACH in the ZONE Data Form. This takes care of the Design Infiltration. ( I am assuming you want Design Conditions to include the open door. If this is not true, then skip this step.).

  5. Now, multiply the ACH values in the BUILDING | Air Infil Data Form times the Volume of the ZONE.

    This should be the size of your Makeup Air FAN.

  6. Change the Specific Leakage Area in the DOOR | Detail Data Form back to where you want it (not 144 in2/ft2).

  7. Add a Makeup Air FAN to the ZONE (not the SYSTEM).

  8. In the Make Air FAN:
    1. Set Fan Location to Makeup Air,
    2. Set CFM to the value you calculated in step 5.
    3. To get the Input Capacity to 0 Watts, set the Fan Motor Efficiency to 0.
    4. Set the Fan Schedules to "Custom."

  9. In the FAN | Detail Data Form, set the Fan Volume Control to "Always On."

I can’t find the answer to your question ? Try checking our User Forums.

Otherwise feel free to contact our Tech Support staff at (805) 329-6565, or via email at helpdesk@abraxasenergy.com.

MetrixMarketManagerReportMakerOption C