HVAC Calc - Window Work Around, cement, ec..)

[danf58]

I'm considering re-buying HVAC-Calc ( I bought it some time ago w/the 2 month version as I built my house). This time to consider insulation and ac/h tightening implications to load. But, it's not really oriented for some of these things. So, a few questions:

1) Any idea how I tell it what r value window shade I'm considering. So much heat flows through a window I'd think this would matter, but it barely acknowledges shades and give no "R" rating. Any idea's how to vary r value's of blinds?

2) What does one use for a poured foundation? It's neither block (airgap) nor ICF...

3) Does it account for fiberglass reduced performance as temp drops? I know it give us R ratings, but fiberglass losses "R" performance as it cools rather significantly...

[cem-bsee]

Item 3= Wrong

[dan sw fl]

So, a few questions:

1) Any idea how I tell it what r value window shade I'm considering. So much heat flows through a window I'd think this would matter, but it barely acknowledges shades and give no "R" rating. Any idea's how to vary r value's of blinds?

2) What does one use for a poured foundation? It's neither block (airgap) nor ICF... ..

U= 1/R

1) U-value of single pane = ~ 1.2
U-value of double pane = 0.3 - 0.8

Get the SHGC (tinting) correct for Your window
Clear 0.7
Light Tint 0.5
HIgh Performance 0.3

Look at PPG website for many windows.

http://corporateportal.ppg.com/NA/Id...ssOverview.htm

Blinds about 20% less.
IE Clear 0.7 without 0.57 with blinds.
Obviously, a large variation.

2) perhaps R-1 or R-2

[danf58]

CEM-BSEE:

You would be one of the few to think that. But I appreciate the thought anyway.

Dan sw:

I hate to be dense, but I don't see how that tells me the ratings for the existing shade options in HVAC-Calc or a way to add R value for shades to it. Can you clarify?

[dan sw fl]

..., I don't see how that tells me the ratings for the existing shade options in HVAC-Calc or a way to add R value for shades to it. Can you clarify?

Do you know if your windows are tinted? Double pane?

SHGC for blinds would be about 20% less windows.
IE Clear SHGC = 0.70 without blinds
_______SHGC = 0.57 with blinds.

Input in HVAC-Calc is up to you. I use Wrightsoft RSR

SHGC = Solar Heat Gain Coefficient = .875 * SC
__SC = Shading Coefficient


________

# 3
... but fiberglass losses "R" performance as it {cools < NOT } absorbs moisture rather significantly...
# 3

[danf58]

Ah, not a HVAC-calc user. That explains it. But anyway, double pane.

See, in hvac calc ( the issue at hand) there appears to be no way to enter in the parameters you mention. A simple interface (I assume that's why it's liked). But support is very limited. Don expects the user community to answer most questions....

#3. I didn't follow again. Cryptic mood tonight maybe? anyway, yes, we'd agree it absorbs moisture too, and that is bad as well for it's performance....

[dan sw fl]

Ah, not a HVAC-calc user. That explains it. But anyway, double pane.

See, in hvac calc ( the issue at hand) there appears to be no way to enter in the parameters you mention.

Double pane, low E and shaded are easily input in Room / Wall / Windows

[danf58]

Yes, they are. Maybe I wasn't clear. How is the "R" value of the shade set, what is assumed "R" value of the shades that exist, or what is some other way of assigning a "R" value to the shades?

[dan sw fl]

Yes, they are. Maybe I wasn't clear. How is the "R" value of the shade set, what is assumed "R" value of the shades that exist, or what is some other way of assigning a "R" value to the shades?

Check
ASHRAE Fundamentals
or

Chapter 6 Windows & Doors at

http://southface.org/web/resources&s...ders_Guide.pdf

[danf58]

OK. Thanks dan.

Anybody else care to comment on how I might be able (WITHIN HVAC-CALC) to assign different "R" values to different window shade treatments?