WARM UP #3D: WINDOW- VENTILATION


OBJECTIVES: In this warm up you will:

Learn about Energy Scheming:

Learn about energy:

Learn about architectural design implications:

PROCEDURE:
1) Resize the Netscape window to a 2" wide narrow strip on the right hand side of the monitor.







2) In this exercise you will modify a file created in Warm Up
3 Intro. Open Energy Scheming by double clicking the folder and application icon, then open the file (your last name) - Bldg 1 South 100.



3) Arrange the Energy Scheming window and the Netscape window like this.




4) Under the file menu, choose Save Building File As.... Save the file as "(your last name) - Bldg. 1 S/W 100 Vent".




5) Select the take off layer and create a west elevation with 100 sf of double pane double hung glazing with no internal or external shading. Change the window in the south elevation to double hung. This makes the window operable so that it may be available for ventilation. For now we will look only at cross ventilation. Save.




6) Select Graphic report from the View menu. Set the floating palette as shown.





7) Calculate and examine the graphic report. Remember that you can get more information by placing the cursor on any hour in the graph and holding down the mouse button.

8) Wind must be from the appropriate direction (no more than a 45° angle of incidence) and of sufficient speed to be used for cross ventilation. The rule of thumb for the outside air temperature is that it must be at least three degrees below the maximum thermostat setting (default is 78° ). Unless instructed otherwise in the schedules, Energy Scheming will assume the windows are open when the outside temperature is cool enough to cross ventilate. However, if the user deems it necessary to prevent ventilation, cross vent icon can be unselected to force the program to not use cross or stack ventilation. (the icons are located under area input in the window specification screens, see image associated with item 5 above)

Questions

Please answer the following questions using the graphic reports:

9) Look at the days in June and September. Why is there no cross ventilation after 9 am in June and after 11 am in September?

The wind is coming from a direction that cannot be used by the windows in their current orientation.
The exterior temperature is too high (less than three degrees below the maximum thermostat setting).
The wind speed is too low.
The windows are not openable during these hours.

10) Look at the days in March clear and December clear. Why is there no cross ventilation after 4 pm in March and between 2-3 pm in December?

The wind is coming from a direction that cannot be used by the windows in their current orientation.
The exterior temperature is too high (less than three degrees below the maximum thermostat setting.
The wind speed is too low.
The windows are not openable during these hours.


11) What are ways to improve ventilation or reduce conduction loss?

Add a 20 sf double glazed casement window in the north elevation (100% openable).
Move the climate to Phoenix.
Raise the maximum allowable thermostat setting to 83 for June and September and lower the minimum allowable thermostat setting to 60 for March and December.
Replace the clear double glazing with low-e double glazing (cooling).



12) Click here if you would like to see the correct answers.


Return to:
Warm Up #3 Intro
Warm Up #3A: Orientation
Warm Up #3B: Solar Savings Fraction
Warm Up #3C: Shading

Go to:

Exercise #3A

Cool Down #3A


Return to: Topics Page

 

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