Look
for this symbol when the subject is Energy SchemingINTRODUCTION TO WARM UP...
#1A - WALL AREA
#1B - WALL R-VALUE
#1C - WALL T
#1D - SAMPLE EXERCISE/QUESTIONS
OBJECTIVES: In this warm up you will learn:
Objective 1) About how to operate Energy
Scheming.
Look
for this symbol when the subject is Energy Scheming
Objective 2) How heat flows through a wall depends upon R-value,
delta T, and wall area.
Look
for this symbol when the subject is energy
Objective 3) How architecture can express: reduced skin area,
insulated walls, and delta T
Look
for this symbol when the subject is architecture
Note: Many of the images (smaller ones with highlighted borders) can be clicked on to expand to a larger view.
PROCEDURE:
1) Building file: Mac users click here to download the file onto your desktop.
PC users click here and follow instructions starting at step 4.
2) Position your internet browser window as a 2" wide strip on the right hand side of the
screen.
3) Double click on the Energy Scheming folder.
4) For Mac users: Drag the Warm Up 1 file from the Desktop over the Energy
Scheming application icon to open it. OR open from within the Energy Scheming application (File->Open).
For PC users, click here for instructions.
• The screen should look like this:
(you can click on this screen to get an enlarged view)
5) The Energy Scheming window should appear on the
left and the browser window on the right.
6)
Click on the draw layer icon to change to the takeoff layer.
Hold mouse down on the drawing drawer.
7)
Select elevations.
8)
Double click on new elevation.
9)
Select south on the compass. Set the scale to 1" = 10' Close the
window using the close box in upper left corner. If you close and
realize that you selected the wrong compass direction or scale,
select Review Drawing Info... from the View menu. Correct the compass
direction (type the correct title) or scale.
10)
Double click on the south elevation icon.
11)
Double click on the walls icon.
12)
Double click on the new walls spec icon.
13)
When you move the cursor off the window and over the drawing area, it
will turn into a small tape measure. This is the takeoff tool. Click
and drag to create a roughly square takeoff of exactly 100 s.f. (Area
is in the upper left corner of the New Wall Spec window.) Close the spec
window by clicking its close box.
If you created a takeoff that is too small or too big, you may delete
it by selecting the thumbs down tool (in the palette on the left) and
clicking on the takeoff. Or you may resize the takeoff by selecting
the arrow tool, and then clicking and dragging the corner boxes of
the takeoff.
Then close the New Wall Spec window.
14) Select graphic report from the view menu.
15)
Click on the calculate button on left side of the screen.
16) Your graph should look like this. You should see 4
typical days of the year, with the hours along the horizontal axis, heat gained by
the building in BTUs above the zero line and heat loss below the
line.
17) You can get more information about any hour on the graph by
putting the cursor on an hour bar and holding the mouse button
down. Try it.
18) Saving your building file is very important. And if you 'Save
Building File as...' you can create a trail of building files in case
the program bombs. Save your building file now.
A building that performs well will have graphic report bars as short as possible
indicating reduced heat flow through the wall.
The basic conduction heat flow formula is:
Q=(A)(deltaT)(U), or heat flow equals area times the
difference in temperature between the two sides of the element times
the element's U-value, where U=1/R.
This formula tells us that in order to change an element's conduction
performance there are three variables we can manipulate. All three
variables have architectural implications .
area: reduce skin area to reduce heat gain/loss
R value : change materials to increase the R value.
deltaT: change the thermostat setting to permit higher (or lower when
there is excess loss) inside temperatures. Change the surface
reflectivity to decrease or increase solar gain and therefore surface
temperature.
Warm Up #1A: Wall Area
Warm Up #1B: Wall R-Value
Warm Up #1C: Wall delta T
Warm Up #1D: Sample Exercise #1 Questions
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