Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Fenestration Condensation

Avoiding frost, moisture, mold, discoloration, and decay
by

Conspectus, Inc.

on 19 January 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Fenestration Condensation

Fenestration Condensation
Bad Examples
Good Examples
Photo: EFCO
Mixed Example
Product Selection Considerations
Glass Position: flush outside, center, interior. May not have separate testing.
Pour & debridge vs thermal struts.
Fiberglass pressure plates for curtain wall.
Edge spacer options for insulating glass units.
Extended mullion caps may act as heat sinks and are probably not tested to see how they affect thermal performance criteria.
Design Considerations:
Orientation with regard to sunlight.
Position of fenestration: flush with wall or recessed?
Anchorage to uninsulated elements.
Alignment of thermal barrier with fenestration thermal breaks, which may be different for curtain wall, storefront, and windows.
Exposure to drainage cavity in wall.
Sills or panning that act as thermal bridges.
Air infiltration. Neither AAMA nor NFRC take air infiltration into account for condensation resistance.
Uninsulated shim spaces.
Uninsulated corner trim.
Location of exterior sealant bead.
Interior design humidity.
BUT
The best laid plans ...
Closed drapes or shades.
Temperatures lower than design criteria.
Exterior wind velocity.
HVAC operation.
Sealant discontinuity or failure that lets cold air into shim space.
Overall Performance
Thermal
Condensation
Average values for entire assembly
U-Value, SHGC, Air leakage
Component & detail specific
Short circuits have great impact
=
Thermal Weighting
COG - Center of Glass
EOG - Edge of Glass
Frame
size & configuration matter!
36 x 48
COG
EOG
Frame
45.9%
26.8%
27.3%
30.0%
32.7%
37.3%
24 x 36
37.1%
29.7%
33.2%
24 x 48
Controlling Condensation
Traditional
Current
Air movement
Air exchanges
Limit air leakage
Reduce air exchanges
Improve fenestration performance
NB:
Optimal interior 30% RH
requires high performance
Available Test Standards
AAMA 1503
NFRC 500
Voluntary Test Method for Thermal Transmittance and Condensation Resistance of Windows, Doors and Glazed Wall Sections
Procedure for Determining Fenestration Product Condensation Resistance Values
Physical test with thermocouple surface temperature measurements
Condensation Resistance Factor - dimensionless Scale 30 - 80
Weighted value for entire assembly
Methodology:
Result
Condensation Resistance - dimensionless Scale 1 - 100
Lowest of Frame, COG, and EOG values
Methodology:
Result
Computer simulation at 30, 50, & 70 % RH with physical test verification
Test Conditions - both tests use the same
Outdoor: 0 deg F, 15 mph wind
Indoor: 70 deg F
Available Tool
AAMA Condensation Resistance Factor Tool
Input:
Output:
dew point temperature
recommended CRF
outdoor design temp
indoor design temp
indoor RH
Manufacturer Reporting
Energy Star requires NFRC U-value & SHGC
NFRC labeling requires
U-Value
SHGC
Visible light transimittance
Air leakage
NFRC Optional Reporting
condensation resistance
IGU Only
Good
Bad
What makes the difference?
Design Considerations
Framing thermal breaks and glass position
Control air leakage
Heel bead sealants?
Gap and crack foam sealant?
Optimize glass performance
EOG
Gas selection
Interspace dimension
Edge spacer material
Spacer Materials
metal
warm edge
stainless steel
aluminum
stronger - thinner wall
less conductive
proprietary types
Butyl rubber; Swiggle Seal by Tru-Seal Technologies
Tin plated or stainless steel: Intercept by GED Integrated Solutions
Stainless steel dual seal: XL Edge by Cardinal Glass Industries
Composite Laminate: DuraSeal by Quanex Building Products
Silicone foam: Super Spacer by Quanex Building Products sealed with butyl
Polymer and stainless steel: TGI-Spacer by Technoform Glass Insulation

Full transcript