What Should I Do About My Windows?

Peter Yost BuildingGreen

February 9, 2011

Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to

AIA/CES for AIA members. Certificates of Completion for both AIA

members and non-AIA members are available upon request. !

This program is registered with AIA/CES for continuing professional

education. As such, it does not include content that may be deemed

or construed to be an approval or endorsement by the AIA of any

material of construction or any method or manner of handling, using,

distributing, or dealing in any material or product. !

Questions related to specific materials, methods, and services will be

addressed at the conclusion of this presentation.

Learning Objectives!At the end of this program, participants will be able to:!

•" Make fair comparisons between window replacement and window retrofit

attachment options.

•" Summarize the key attributes of retrofit window and attachment options

•" Compare window retrofit options on a level playing field

•" Recommend to clients the highest performance, most cost-effective window

retrofit options

What to do about my windows?

Options Attributes

Options

Interior

!" Blinds

!" Drapes

!" Roller shades

!" Fixed panel

!" Quilt

!" Cellular shades

!" Films

Replace

!" Full unit

!" Insert

!" Sash replacement

!" Storms

!" Shutters

!" Awnings

!" Roller shades

!" Screens

!" Landscaping

Exterior

Attributes

Thermal

!" Insulation

!" Air tightness

!" Solar heat gain

!" Comfort

!" Condensation resistance

Use

!" Ease of operation

!" Adjustability

!" Ease of cleaning/repair

!" Maintenance/durability

!" Visual transmittance

!" View

!" Daylighting

!" Glare

!" Privacy

!" aesthetics

Visual

Attributes (cont’d)

Economics

!" Materials/equipment costs

!" Installation costs

!" Heating/cooling savings

!" Service life (attachment)

!" Service life (window)

Other

!" Ease of install

!" Availability

!" Acoustics (noise reduction)

!" Role in ventilation

!" Security

NFRC - Attachments

!" Applied Films (label)

!" Awnings

!" Exterior Attachments

!" Interior Attachments

!" Storms (next?)

The LBNL Project !" Advisory Committee – mix of private industry

representatives, expert consultants, LBNL research staff

!" Literature Review – “gray” and “white” information resources

!" Field Testing – Comparative IR imaging under standard conditions & supported by additional metrics

!" Guidance Tools – DOE fact sheets and web-based tool (decision process, including modeling/calculators)

Advisory Committee !" John Gant – Glen Raven

(awnings)

!" Mike Cienian – Hunter Douglas (cellular shades)

!" Steve DeBusk – CP Films (surface-applied films)

!" “honorary” member – Gordon Clements, Gordon’s Décor (cellular shades)

!" Tom Culp (storms)

!" John Carmody & Kerry Haglund (CSBR)

!" Nils Petermann (ASE)

!" LBNL Steve Selkowitz Charlie Curcija Dariush Arasteh Christian Kohler Robert Hart Howdy Goudey

LBNL Literature Review !" Early stages – laboratory testing, field testing, modeling—

it’s pretty early in the game all around

!" Research mosaic – different countries, test methods, base cases, options – it’s a jungle out there.

!" Results alignment – surprisingly good - e.g. Energy Plus and ESP-r

!" Terminology & classification – it’s a jungle out there (two jungles – science community and general public)

!" Quality of manufacturer-posted info

!" Window/attachment interactions

Field Testing !" Obtain visually-compelling, comparative, thermal-

performance portrayals of residential windows with and without the benefit of window retrofits.

!" Achieve this with the combination of thermocouple and heat flux sensors, IR and digital camera images.

!" Develop above into a protocol or standardized test.

Field Test Site

Field Test Site

Field Test Window

Test Team

Test Setup

Equipment credit: Nathan Yost

What the Window “Sees”

Double-pane low-e, no attachment, -20 Pa

Interior Storm Panel – single-pane

Insulated cellular shade (ST), double-pane low-e

Window quilt, low-e double pane

Single-pane, no attachment

interior low-e storm over “vintage” single-pane

wood frame double hung

Interior low-e storm over “base case” double low-

e Ar sash inserts

“base case” dual glazed low-e Ar double

hung sash inserts

storm double IGU double storm triple

Room facing low-e film on single wood framed double

hung with exterior clear storm and !P

Interior low-e storm over “base case” double low-

e Ar sash inserts

Honeycomb shade with side tracks over “base case” double

low-e Ar double hung sash inserts

storm double IGU double + insulating shade storm triple room side low-e

Interior Low-e Storm Over “Vintage” Single-pane Wood Framed Double Hung With Varied Pressure Difference

No !P 10 Pa !P 16 Pa !P

Interior screen (Inflector) radiant side in (winter)

Interior storm Indow Window

Interior storm panel (WindowSaver)

Home Energy magazine: July/August 2002

DePaola Home

Existing Conditions

!" 60-year old ranch

!" Madison, WI (7800 HDD)

!" 224 sq. ft. wood, (mostly) double-hung, friction-slides, single-pane

!" Conventional aluminum, triple-track exterior storms

!" Beautiful mahogany window trim (interior)

Issues

!" Storms fog or ice up

!" Cold drafts near windows

!" Double-hungs “stick” or won’t stay open

!" Some windows no longer lock

!" UV degradation

!" Storm operation is also poor

DePaola Home - Options !" Repair

!" Replace

!" Single-pane + Cellular Shade

!" Single-pane + exterior storm low-e

!" Single-pane + interior film

!" Double-pane + one of the above

Modeling !" WINDOW – NFRC

simulation tool from LBNL (free)

!" RESFEN – whole house tool from LBNL (free)

!" HomeEnergySaver (HES) & HESPro

DePaola Home - Decision !" Repair – yes, but went beyond to get more of what

they wanted

!" Insulating shades – did not solve enough issues and they did not like the aesthetics

!" Interior storm – no: still need weather-protection of x-storm; no ventilation; other issues unchanged

!" New low-e storms – not enough ROI, still operation problems with existing sashes

!" WINNER – sash replacement (over inserts or full replacement)

Window Retrofit Web-based Tool Wireframes

Tell us where you live. 01501

Notes: This question determines relevant climate conditions.

Back Next Get Results

Zip Code:

Check all special conditions that apply:

! Wind"

!""Snow load

! Window protection (catastrophic weather)"

! I rent or live in a condo

! My house is in a historical district"

Notes: This question helps determine vital features of the final results. For example if Window protection is needed then exterior storms and/or exterior roller blinds will be recommended.

Back Next Get Results

What are your biggest issues?

Notes: Results can be narrowed using this table. Ranking the requirements allows the tool to focus on the most important issues.

Back Next Get Results

1st 2nd 3rd N/A

Fading !

Hurricane protection !

Condensation !

Security !

Storm protection !

Solar heat gain !

Drafty windows !

Glare !

Privacy !

Heat loss !

Windows don’t work !

do

Determinate Existing Conditions

Notes: These questions may be used to determine cost/savings analysis for later versions of the tool.

Back Next Get Results

Scope of Retrofit: Windows

Total Number of Windows

OR

West facing windows

East facing windows

South facing windows

North facing windows

Scope of Retrofit: Area

Option 1: Total sq. ft. of window area

Option 2: Total sq. ft. of floor area

! Low window to floor area ratio ! Medium window to floor area ratio ! High window to floor area ratio

Window Condition

! Brand New ! Must be replaced for safety/fogging ! Performance properties

7 95

Notes: Some retrofit options will be ignored (or greyed out) depending on the budget input.

Back Next Get Results

How much are you willing to spend?

#" Total $

OR

#" $ per sq. ft. of window

OR

#" $ per window 500

do

Notes: This page shows the top 4 results along with a summary of answered questions.

Back

Ranked Results

! Exterior Metal Rolling Shutter

! Exterior Storm (tinted)

! Exterior Fabric Roller Shade

! Interior Roller Shade

01501 Zip Code:

Special conditions:

! Wind"

! Window protection (storm)

Total Number of Windows

Total sq. ft. of window area

Window Condition ! Brand New

7

95

1st 2nd 3rd

Fading !

Hurricane protection !

Security !

Solar heat gain !

Privacy !

$ per window 500

Summary

Compare Results

do

Notes: This is an example page of a specific window treatment.

Back

Best Option

Exterior Metal Rolling Shutter

Attributes:

Caveats:

do

Notes: This is an example page of a specific window treatment options compared.

Back

Exterior Metal Rolling Shutter

Attributes:

Caveats:

Exterior Storm (tinted)

Attributes:

Caveats:

Results Comparison

Coming Soon! !" Website (downloadable fact sheets)

!" Web tool

!" Summer (shade) IR-based field testing

The R-value of a Vermont Cat

Course Evaluations!

In order to maintain high-quality learning experiences, please access the evaluation for this course by logging into CES

Discovery and clicking on the Course Evaluation link on the left side of the page.

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