BASC Search | Building America Solution Center

Casement windows allow full airflow through the entire window area

Publication Date

Tue, 06/28/2022 - 12:00

Install Window Shutters

Author(s)

Knowles III Hal S,

Ruppert Kathleen C,

Lenfesty Karla A,

Halderman Barbara

Organization(s)

University of Florida IFAS Extension

Publication Date

January, 2021

This document covers how broken windows can allow wind and rain inside the house and even lead to roof failure.

A screened-in porch will protect windows from rain, provide shade, and allow more airflow through windows than window screens would

Publication Date

Fri, 09/24/2021 - 12:00

The Importance of Windows in Hot Climates

Author(s)

Ueno Kohta

Organization(s)

Green Building Advisor,

GBA

Publication Date

July, 2020

Article from Green Building Advisor on the importance of window selection in hot climates, with an emphasis on window glazing.

Seven categories of exterior window shading attachments, identified on the DOE Efficient Window Coverings website.

The DOE Efficient Window Coverings website identifies twelve categories of interior window shading attachments.

Publication Date

Tue, 07/25/2023 - 12:00

Shading and Solar Control for Windows and Skylights

Guide describing various methods of shading and solar control to reduce heat gain through windows.

High-Efficiency Window Air Conditioners

Author(s)

U.S. Department of Energy

Organization(s)

DOE

Publication Date

September, 2013

Factsheet profiling a simple modification that can be made to window air-conditioners to improve their energy efficiency.

Wrong - this building provides no overhangs, minimal window shading, and clear window glass resulting in high solar heat gain.

Publication Date

Fri, 09/30/2022 - 12:00

Window Attachments for Solar Control and Energy Efficiency

Guide providing information on interior and exterior window attachments for shading, glare control, noise control, protection from high winds, privacy, and reduced heat loss in winter.

Right – This shrub has been pruned to allow views out the windows of this home while providing shade to walls, windows, and roof.

Publication Date

Thu, 09/29/2022 - 12:00

This depiction of a saddle installed window heat pump does not obstruct window use and provides fairly quiet 120 Volt operation

This wall and window assembly has excessive framing around the windows, which can lead to heat gain in how climate zones.

Publication Date

Thu, 01/01/2015 - 12:00

Right – The canopy of this tree is high enough to allow views out the windows of this home while providing excellent shade to walls, windows, and roof.

Publication Date

Thu, 09/29/2022 - 12:00

The Efficient Window Coverings website allows direct comparison of various window attachment types based on thermal, visual, functional, and installation and durability criteria.

The window awnings on this house provide a simple but very effective way to reduce solar gains while still allowing view, daylight, and ventilation through the windows

Publication Date

Fri, 01/08/2021 - 12:00

Even when wind is blowing parallel to a wall, an open casement window can create a zone of higher pressure near the window opening, driving airflow into the house

Publication Date

Fri, 09/24/2021 - 12:00

Measurement of the Solar Heat Gain Coefficient and U Value of Windows with Insect Screens

Author(s)

Brunger Alfred,

Harrison Stephen,

Dubrous Francois M

Organization(s)

American Society of Heating,

Refrigerating,

American Society of Heating Refrigerating and Air-Conditioning Engineers,

ASHRAE

Publication Date

January, 1999

Technical article presenting the results of an analysis on the effect of insect screens on window solar heat gain coefficients and U-values.

Right – this commercial building employs good techniques to resist solar heat gain: awnings and pergolas over windows, recessed windows and entryways, deep tinting on glass, and shade plants.

Publication Date

Fri, 09/30/2022 - 12:00

Casement windows or wing walls can create zones of higher pressure (right) and lower pressure (left) to encourage cross ventilation when wind is flowing parallel to window openings

Publication Date

Tue, 10/01/2019 - 12:00

The operable windows in this house are located at occupant level to provide comfort ventilation.

Publication Date

Wed, 06/01/2016 - 12:00

Use this simple calculation to size overhangs above south facing windows.

Publication Date

Tue, 07/30/2019 - 12:00

Right – Strategically placed trees provide shade to the south-facing windows of this building.

Publication Date

Fri, 09/30/2022 - 12:00

Calculate projection factor (PF) by dividing overhang (A) by length of window (B).

Publication Date

Fri, 01/01/2021 - 12:00

HUD 2024 Housing Innovation Showcase Poster: Window Attachments Keep out the Heat

Author(s)

Katherine Cort,

Theresa Gilbride

Organization(s)

Pacific Northwest National Laboratory

Publication Date

September, 2024

Factsheet outlining how window attachments like cellular shades, roller shades, storm windows with low-emissivity coatings, and solar screens are low-cost steps that can be implemented to keep homes cool in the summer.

Right – This tree shades walls, windows, roofs, and grounds for two adjacent homes.

Publication Date

Thu, 09/29/2022 - 12:00

Large deciduous trees provide heat-blocking shade to the walls and windows of this house.

Publication Date

Fri, 09/09/2022 - 12:00

Right - Covered porches protect the south-facing windows and doors of this building from solar heat gain.

Publication Date

Fri, 09/30/2022 - 12:00

These aluminum Bahama shutters shade west-facing windows from afternoon sun and are approved for hurricane protection

Publication Date

Wed, 07/26/2023 - 12:00

This house has key features to block heat such as such as tree shading for the west wall and roof, minimized west-facing windows, and a porch roof, floor, and wing walls creating deep architectural overhangs and fins to shade south-facing windows

Right - This house has key features to block heat such as such as tree shading for the west wall and roof, minimized west-facing windows, and a porch roof, floor, and wing walls creating deep architectural overhangs and fins to shade south-facing windows

Publication Date

Fri, 09/24/2021 - 12:00

ACEEE 2024 Summer Study on Energy-Efficiency in Buildings Factsheet: Window Coverings that Can Take the Heat

Author(s)

Katherine Cort,

Theresa Gilbride

Organization(s)

Pacific Northwest National Laboratory

Publication Date

September, 2024

Factsheet describing how window shades can keep out unwanted heat, detailing the most effective products and practices.

Locating windows on adjacent and opposite sides of the house will allow cross ventilation regardless of wind direction

Publication Date

Fri, 09/24/2021 - 12:00

Whole-house fans draw outside air through windows into the home and exhaust it into a vented attic

Reference

Measure Guideline: Ventilation Cooling

Author(s)

Springer David,

Dakin Bill,

German Alea

Organization(s)

Alliance for Residential Building Innovation,

ARBI,

National Renewable Energy Laboratory,

NREL,

Davis Energy Group,

U.S. Department of Energy,

DOE

Guide describing proper application, design, and installation of mechanical ventilation cooling systems for homes located in hot-dry and cold-dry climates, as well as a means of understanding the benefits, costs, and tradeoffs of these systems.

Publication Date

Sun, 04/01/2012 - 12:00

External solar screens are an effective way to reduce solar heat gains through windows while maintaining view.

The patio roof on this home provides full shade to large glass doors and windows, reducing the home's heat gains.

Publication Date

Sat, 07/01/2000 - 12:00

Right – the building on the right employs light-colored walls, deep tinting, and deeply recessed windows to minimize solar heat gain

Publication Date

Fri, 09/30/2022 - 12:00

Interior window attachments such as these light-filtering roller shades can reduce heat gains while providing pleasant, diffuse natural light.

Publication Date

Tue, 07/25/2023 - 12:00

Dense hedges can encourage cross ventilation (left image) or not (right image) depending on how they are placed relative to windows

Publication Date

Mon, 01/01/2007 - 12:00

A reversible window fan can operate via thermostatic or remote control and can selectively exhaust air or bring in outdoor air

Publication Date

Mon, 11/14/2022 - 12:00

Right – thermal mass walls, small windows, and recessed porch and trees on the south side of this southwest home help to minimize solar heat gain.

Publication Date

Fri, 09/30/2022 - 12:00

Clerestory windows bring light in from above, reflecting it off of surfaces, making it more appealing than the direct light that comes from skylights

Airflow can be directed across thermal mass in the ceiling, floor, or elsewhere inside the home through various window and louver configurations

Publication Date

Fri, 09/24/2021 - 12:00

Wrong: Single sided ventilation without at least two windows, wing walls, and predictable wind directions is ineffective for generating wind-driven crossflow.

Publication Date

Tue, 10/09/2018 - 12:00

Double fan window units can have multiple operational modes; most often outdoor air will be brought in at night when outdoor conditions are cooler

Publication Date

Mon, 11/14/2022 - 12:00

This infrared image shows little heat gain from north-facing double-pane windows with blinds, but significant heat output from computer monitors

Publication Date

Mon, 11/14/2022 - 12:00

Portable air conditioners offer flexibility with where they are located, but usually need to be installed near a window as they require one or two intake/exhaust ducts connected to the exterior

Wrong – This multi family building appears to be done in traditional southwest architecture but the lack of useful overhangs, dark colored walls, and lack of tinting on windows will result in significant solar heat gain.

Publication Date

Fri, 09/30/2022 - 12:00

Right - Dense vines growing on a covered trellis along the west side of this home provide effective shade for the wall and windows and create a shaded, protected walkway and outdoor seating area.

Publication Date

Thu, 09/29/2022 - 12:00

A cool room should have low enough heat gains to be easily cooled by a small single-zone cooling system such as a mini-split or a window air-conditioner as shown here

Publication Date

Mon, 11/14/2022 - 12:00

The design of this home incorporates multiple methods to reduce summertime solar gains including roll-down exterior blinds, wide exterior horizontal louvers, minimized east/west-facing windows, and vegetation.

Right: This house plan orients broad building surfaces away from the west and east, trees are used to shade the west and east, and large overhangs shade windows on the south wall

Publication Date

Fri, 09/24/2021 - 12:00

Porch roofs, pergolas, and large overhangs can effectively shade windows and doors facing south, southeast, southwest, or even due east or west for most of the day if the overhang is very deep and sufficiently wide.

The south face of this home has an overhanging second floor, a pergola, and a roof eave to provide effective window and door shading for both floors in the summer without blocking view, diffuse daylighting, breezes, or ingress/egress

This room has several passive and low-energy cooling features including a ceiling fan, fully operable French doors, window shading, an outdoor water feature, and light-colored hard-scaping.

Publication Date

Tue, 06/28/2022 - 12:00

A 5,000- 6,000 Btu/hr air conditioner drawing about 500 watts can be installed in one window of a designated cool room (it is important that the installation is insulated and well-sealed

An NFRC glazing system energy performance label will report U-factor, solar heat gain coefficient, visible transmittance, and air leakage; if the window is ENERGY certified, the ENERGY STAR label will be located next to the NFRC label

Publication Date

Thu, 05/18/2023 - 12:00

Right - In cooler climates, landscape shading should focus on the east- and west-facing walls, while leaving the south side of the house clear for solar access in winter (well-sized roof overhangs could provide summer shading for the south-facing windows)

Publication Date

Fri, 09/24/2021 - 12:00

Sheer shades can provide very effective daylighting and glare control while maintaining a softened view to the outside

Publication Date

Tue, 11/03/2015 - 12:00

Pleated blinds provide cooling savings in summer by blocking and reflecting sunlight, while allowing some diffuse daylight to pass through.

The light-colored exterior roll-down shades on this building, and the shaded entryway provide very effective control of solar heat gain

Publication Date

Thu, 01/28/2021 - 12:00

Creating a Cool Room for Extreme Heat Events

Guide describing how to create a designated shelter-from-heat space in a home to help occupants successfully weather an extreme heat event.

ASES March Webinar: Uncoupling Solar Light and Heat in Passive Solar Design

Author(s)

American Solar Energy Society

Organization(s)

ASES

Publication Date

March, 2022

Presentation from American Solar Energy Society on using spectrally selective window technology for passive solar design.

How to better equip your home for hotter temperatures

Publication Date

July, 2021

Author(s)

CBC News

Organization(s)

CBC News

Video from CBC News on long-term solutions for building homes for hot weather, including using radiant cooling and energy efficient windows.

Right - These interior solar screens help control glare and solar heat gain while maintaining view to the outside.

Climate Safe Housing - Strategies for Multifamily Building Resilience

Author(s)

Enterprise Community Partners

Organization(s)

ECP

Publication Date

July, 2023

Webpage providing information on how window shading can reduce heat gain in summer and heat loss in winter.

Passive and Low-Energy Cooling

Guide describing various ways of implementing passive and low-energy cooling techniques for a house.

Multi-layer honeycomb cellular shades such as these can provide summertime energy savings by blocking and reflecting solar heat, as well as wintertime energy savings by providing added insulation.

Publication Date

Thu, 10/01/2015 - 12:00

Emergency Air Conditioning and Food Refrigeration

Guide describing methods for providing space cooling and refrigeration during extreme heat events and/or power outages.

Exterior Doors Are Insulated, Impact Rated, and Fire Rated

Guide describing the use of doors that are insulated and are impact rated or have protective coverings for resistance to hurricane, high winds, wildfires and thermal losses.

Right- Landscaping shades the entry on the south west corner of this hot dry climate building.

Publication Date

Fri, 09/30/2022 - 12:00

Right – deeply inset entryways and overhangs provide shade to reduce solar heat entry to this building.

Publication Date

Fri, 09/30/2022 - 12:00

Landscaping and Bahama shutters can provide important shade for a designated cool room

Publication Date

Mon, 11/14/2022 - 12:00

Right – Deep overhangs, pergolas, and covered entryways minimize heat gain in this commercial building in the hot-dry climate.

Publication Date

Fri, 09/30/2022 - 12:00

Wrong – The south side of this building in Arizona has very little architectural or landscape shading to block solar heat gain.

Publication Date

Fri, 09/30/2022 - 12:00

There are multiple options for exterior shading of east and west facing glazing systems to avoid direct beam radiation

Design for Extreme Heat

Information guide describing ways to design a home to be resistant to extreme heat.

Passive Solar Design Principles

Publication Date

October, 2013

Author(s)

Master Builders Victoria

Organization(s)

Master Builders Victoria

Video from Master Builders Victoria on passive solar design principles for home construction.

Right – Horizontal overhangs on this house block sunlight in the summer while allowing it in during winter

Infrared photometry shows the impact of a roof overhang on the south façade of a home, where the unshaded patio stonework is significantly hotter than the shaded portions of the patio and wall surfaces (temperature scale shown is in Celsius).

Exterior shading devices such as awnings or overhangs can significantly reduce cooling loads

Publication Date

Sun, 10/14/2007 - 12:00

These retractable awnings provide shad to this outdoor living space and reduce heat gain and glare within the home.

Right - These retractable awnings provide shade to this outdoor living space and reduce heat gain and glare within the home.

Publication Date

Wed, 07/19/2023 - 12:00

Right – This model home for the Solar Decathlon competition incorporates vertical trellises and retractable exterior blinds to control solar heat gain.

Sustainable Living Series

Author(s)

Office of Sustainability

Organization(s)

Washington University St. Louis

Publication Date

October, 2019

Presentation by the Washington University in St. Louis Office of Sustainability on saving energy.

NJARNG Sustainability Newsletter June 2016 Volume 2 – Issue 2

Author(s)

New Jersey Army National Guard

Organization(s)

NJARNG

Publication Date

June, 2016

Newsletter providing news and information to members of the New Jersey National Guard.

Construction & Design Considerations in Warmer Climates

Author(s)

Zero Energy Project

Organization(s)

Zero Energy Project

Publication Date

January, 2022

Guidance from Zero Energy Project on construction techniques for warmer climates, such as home orientation, and insulation requirements.

Keeping Homes and Cities Cool in Extreme Heat

Author(s)

Kyle Mittan

Organization(s)

University of Arizona

Publication Date

June, 2021

Article from University of Arizona on keeping homes cool during extreme heat, both personal and system changes.

Be Prepared For Extreme Heat, FEMA V-1004

Author(s)

Federal Emergency Management Agency

Organization(s)

FEMA

Publication Date

June, 2018

Information sheet from FEMA on preparation for extreme heat, including measures for keeping homes cool.

These folding louvered porch doors provide effective shade from low-angle east and west sunlight and can open for views; the photovoltaic panels overhead allow in filtered natural light

Solar Radiation Data Manual for Buildings

Author(s)

Marion William,

Wilcox Stephen

Organization(s)

National Renewable Energy Laboratory,

NREL

Document providing incident solar radiation data and window overhang sizing guidance for multiple locations across the U.S.

This hot climate zone home uses high quality batt insulation to insulate truss-joist headers.

Publication Date

Thu, 01/01/2015 - 12:00

Cooling with Ventilation

Author(s)

Chandra Subrato,

Houston Michael M,

Fairey Philip W

Organization(s)

Florida Solar Energy Center,

FSEC

Publication Date

December, 1986

Report providing recommendations to builders regarding how to reduce cooling loads, use air-circulation fans, natural ventilation, window and building design for natural ventilation, and whole-house fans.

Designing Houses That Keep Their Cool

Author(s)

Wilson Alex

Organization(s)

Green Building Advisor

Publication Date

July, 2013

Article from Green Building Advisor on strategies to take when building homes to reduce the need for air conditioning, including insulation, windows, site selection, and roofing.

Air speeds generated by a typical ceiling fan are in the ideal range for providing occupant cooling without causing disruption

Publication Date

Mon, 12/01/1986 - 12:00

Thermal Performance of External Roller Blinds Retrofit for Offices in the United Kingdom

Author(s)

Ylitalo Hanna,

Ip Kenneth,

Marshal David

Organization(s)

University of Brighton

Publication Date

July, 2023

Conference paper describing a proof of concept trial that demonstrated that external roller blinds can reduce heating loads in a room by 20%.

Designing Energy Efficient New Homes for a Warm Climate

Author(s)

EXtension Home Energy - Cooperative Extension

Organization(s)

EXtension Home Energy - Cooperative Extension

Publication Date

July, 2019

Article from The Home Energy Community of Practice on designing energy efficient homes in hot climate zones, including home orientation, window location, and roof design considerations.

Residential Heating and Cooling Loads Component Analysis

Author(s)

Lawrence Berkeley National Laboratory

Organization(s)

LBNL

Publication Date

November, 1999

Report describing a study using parametric computer simulations of 112 single-family and 63 multi-family residential building prototypes to quantify the contributions of building components such as roofs, walls, windows, infiltration, outside air, lighting, equipment, and people to the aggregate...

Improving The Passive Survivability of Residential Buildings During Extreme Heat Events in the Pacific Northwest

Author(s)

Rempel Alexandra,

Danis Jackson,

Rempel Alan,

Fowler Michael,

Mishra Sandipan

Organization(s)

Applied Energy,

National Science Foundation,

NSF

Publication Date

September, 2022

Study using simulations to understand the impact that shading and natural ventilation would have had on the survivability of non-air-conditioned buildings during the 2021 heat wave in the Pacific Northwest.

Landscaping to Reduce Cooling Load

Guide describing ways to use landscaping to keep a home cooler.

Extreme Heat Overview

Overview guide providing background information on extreme heat in the United States as it relates to homes and links to guides describing specific ways to make homes more resistant to extreme heat.

Passive Cooling Designs to Improve Heat Resilience of Homes in Underserved and Vulnerable Communities

Author(s)

Sun Kaiyu,

Zhang Wanni,

Zeng Zhaoyun,

Levinson Ronnen,

Wei Max,

Hong Tianzhen

Organization(s)

Lawrence Berkeley National Laboratory,

LBNL

Publication Date

August, 2021

This study evaluated 11 measures for passive cooling using four heat resilience metrics with and without grid power in Fresno CA and found the two most effective measures were installing solar-control window films and adding roof insulation; natural ventilation also helped reduce overheating in...