The Efficacy of Energy Efficient Windows and Doors
Pella sorts out the facts and myths
With all the discussion these days on how to save money on utilities, consumers may wonder, is it really worthwhile to replace old windows and doors with more energy-efficient ones? The answer is an unequivocal yes — the proof is in the performance and the utility savings.
The U.S. Department of Energy’s ENERGY STAR® program helps identify products proven to be energy efficient. ENERGY STAR is a government-backed program that helps businesses and individuals protect the environment through superior energy efficiency. In 2004 alone, Americans, with the help of ENERGY STAR, saved enough energy to power 24 million homes and avoid greenhouse gas emissions equivalent to those from 20 million cars — all while saving $10 billion.
In a home, energy efficient choices can save families about a third on energy bills with similar savings of greenhouse gas emissions, according to the Department of Energy.
For businesses, the Environmental Protection Agency (EPA) offers an ENERGY STAR partnership, a proven energy management strategy that helps measure current energy performance, set goals, track savings, and reward improvements. EPA provides an energy performance rating system which businesses have used for more than 21,000 buildings across the country.
"With the high cost of natural gas this winter, choosing energy-saving products is a must for any homeowner. To avoid the sticker shock of high utility bills, consumers should look around their home and identify where replacing or updating items would result in better long-term savings- and a short-term defense against high energy prices," said Kathy Krafka Harkema, energy efficiency expert, Pella Corporation.
By making minor adjustments to their home, consumers could enjoy significant energy savings. To set the record straight on what’s truly effective and what’s not when it comes to energy efficiency, here are commonly-held myths about windows and doors, and the facts:
MYTH: Sealing windows shut is an effective way to conserve energy.
FACT: Sealing windows shut is not only ineffective, it’s dangerous! This myth must date back to the times of early settlers when log cabins featured holes in the wall for windows. Windows must be operable and functioning at all times of the year to provide ventilation and a possible emergency escape route. The emergency escape is especially critical in the winter months when homes are more susceptible to fire and the only quick route out may be through a window.
MYTH: Covering windows with plastic is a great long term solution to cutting the cold air that leaks in through existing windows.
FACT: Plastic over windows is a band-aid approach to larger issues involving windows. If there is significant air leaking in or around windows, the best solution is to replace the entire window to gain maximum energy efficiency and block the outdoor air during cold or hot months.
MYTH: Aluminum windows are just as energy efficient as any other type of window.
FACT: Aluminum is the least energy efficient material for windows. Wood, by its insulating nature, is highly energy efficient. Plus, it’s one of the earth’s few renewable resources. In addition to wood, quality fiberglass and vinyl materials are also good choices for energy-efficient windows and doors.
MYTH: The argon gas in between panes of glass eventually all leaks out so there’s no need for it to begin with.
FACT: Total myth. Different climates require different window technologies for best performance. For energy savings, look for insulating glass with argon-filled, low-emissivity (Low-E) glass coatings to reduce heat transfer through the glass and reduce UV rays.*
MYTH: Storm doors are nice for looks but add no energy savings to a home.
FACT: A properly fitted and solid storm door can add significant savings to a home. According to independent testing, a Pella storm door added to an entryway can reduce energy loss through the entryway by up to 45 percent. A new storm door can pay for itself in energy savings.
MYTH: Putting towels or rugs around leaking entry or patio doors will solve the problem, keeping the cold air out.
FACT: While it might be a logical short-term solution, many homeowners deny the bigger issue — a door may not have been installed properly. Just like windows, it is critical that doors are hung properly for maximum performance. Check the weatherstripping around the door to make sure it seals. Evaluate the door’s threshold. Adjust or replace weatherstripping or threshold seals as necessary to reduce unwanted hot or cold air from entering the home. When replacing entry doors for best performance, safety, or to improve energy-efficiency, select entry door systems that are factory-built to quality standards, such as Pella entry door systems, rather than doors assembled on-site from pieces or components.
Energy efficient products from Pella
Most Pella products meet or exceed the Department of Energy’s ENERGY STAR guidelines. Here are just a few examples of the energy value of Pella products:
Pella® Designer Series® windows and patio doors with triple-pane glass are number one for energy efficiency among top national brands.** Most Architect Series®, ProLine®, Pella® Impervia® and ThermaStar by Pella® products meet or exceed ENERGY STAR requirements of .35 u-values or less.
Pella® Impervia® windows and patio doors, manufactured from Duracast® — the strongest, most durable material available in windows and doors — and featuring Low-E insulating glass, are designed to provide greater energy efficiency. And, unlike ordinary fiberglass, Duracast is sleek and not bulky. Now available in double-hung window styles, in addition to white, tan or brown color options, these high endurance windows and patio doors are National Fenestration Research Council (NFRC)-certified and meet or exceed ENERGY STAR requirements in all U.S. 50 states, helping save on energy costs.
Pella® ProLine® windows and doors provide more value than ever before with additional size offerings to fit a variety of openings in a home or building. Plus with convenient factory pre-finishing options, this product saves money and time in overall construction costs.
ThermaStar by Pella® brings a quality vinyl choice to the table for homeowners or businesses. ThermaStar windows and patio doors are a proven energy efficient option and available in white or almond.
* High-altitude Low-E insulating glass does not contain argon gas
** Superior NFRC U-values and SHGC ratings
Tips for selecting green windows and doors
What is green?
Green buildings are located, designed, constructed and maintained to promote resource conservation and in turn, to help enhance the well-being of occupants. Green buildings use resources wisely, to help minimize negative impacts on occupants and on the environment by:
- Drawing on energy-efficient designs and materials built to last
- Using recycled or sustainable materials
- Helping improve indoor air quality
- Landscaping exteriors to conserve energy and water
- Providing a comfortable, easy-to-maintain, sustainable environment
In addition, green buildings often provide greater design flexibility, can help improve occupant productivity, and help reduce maintenance and replacement costs over the life of the building.
What is sustainable design?
Sustainable design seeks harmony with the environment as it balances human needs (as opposed to wants) with the carrying capacity of the natural and cultural environments. To achieve sustainable design, a variety of strategies are used during the design, construction and operation of building projects. Green building is one of those strategies used in the process to best utilize resources.
Essential elements in sustainable design include: optimizing the site potential for energy efficiency, water conservation, ease of use and security; using environmentally-friendly products, enhancing indoor air quality and simplifying maintenance to help reduce lifecycle costs.
Green is growing
According to the National Association of Home Builders (NAHB), new homes today are twice as energy-efficient as they were 30 years ago, due to cutting-edge green building techniques and technologies available for new and remodeled homes.
Nationwide, roughly 61,000 homes were built using local green building program guidelines from 1990-2004. In 2004 alone, more than 14,000 green homes were constructed.
With the green movement continually on the rise, there are green aspects to consider in every element of a newly constructed building or home. The LEED™ (Leadership in Energy and Environmental Design) Green Building Rating System® is a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. Members of the U.S. Green Building Council (USGBC) representing all segments of the building industry developed LEED and continue to contribute to its evolution.
According to the USGBC, LEED was created to:
- define "green building" by establishing a common standard of measurement
- promote integrated, whole-building design practices
- recognize environmental leadership in the building industry
- stimulate green competition
- raise consumer awareness of green building benefits
- transform the building market
LEED provides a complete framework for assessing building performance and meeting sustainability goals. Based on well-founded scientific standards, LEED emphasizes state of the art strategies for sustainable site development, water savings, energy efficiency, materials selection and indoor environmental quality.
Pella products have been used on several LEED certified projects including gold and platinum ratings.
Green guide
Listed below are recommendations from Pella® Windows & Doors on what to look for in environmentally-friendly products.
Green window and door guide
1. Manufacturer’s commitment to environmental stewardship — Pella’s commitment to environmental stewardship is firmly rooted in the company’s culture, and has been since the company was established in 1925. Founder Pete Kuyper’s words in 1950 are still true today:
“We recognize our responsibilities as stewards of our natural resources and the environment, and will avoid wasteful or harmful disregard of the environmental effects of our operation.”
2. Energy efficiency — the building envelope is a key part of how a building will perform in relation to energy efficiency. When a building envelope has windows and doors, there are holes in that envelope that could compromise the energy efficiency. That’s why window and door choices are critical, because high quality and energy efficient windows and doors should be used.
- Wood windows with triple glazing and blinds between the glass are one option because they offer excellent U-Values and thermal properties of the wood. Pella® Designer Series® is GreenSpec® (1) listed and in fact, Designer Series windows and patio doors with triple-pane glass are number one for energy efficiency among top national brands.* Most Architect Series®, ProLine®, Impervia® and ThermaStar by Pella® products meet or exceed ENERGY STAR® requirements of .35 u-values or less.
3. Recycled content — evaluate the amount of recycled content used — this can be post-consumer or post-industrial. Pella products have a recycled content of over 20 percent post-industrial.
4. Indoor air quality — the main issue with indoor air quality is VOC (Volatile Organic Compounds), so at the very least products need to meet some type of requirements such as Green Seal®.
- Pella products that are unfinished or factory finished with Pella pre-finish or prime meet VOC and chemical components limits of Green Seal® Standard GS-11 requirements.
5. Daylighting and views — daylighting and views are a key window property for green, because windows allow for natural daylighting which reduces or eliminates the need for artificial lighting saving on energy costs. A key component is to place windows and shading devices in a location that maximizes daylighting and minimizes heat gain. Views are maximized if all occupants have visibility to the outdoors. Studies show this contributes positively to both work environments and life improvement.
6. Increase ventilation effectiveness — operable windows can assist with this, if the building is going to be naturally ventilated to reduce the need for mechanical systems for fresh air flow.
7. Light pollution — lights can pollute the night sky and neighboring properties, including the interior lights from a building. The goal is to eliminate light trespass from the building.
- Pella® Designer Series® with blinds or shades between the glass are a logical solution to decrease light pollution because of the easy and efficient way to decrease light.
8. Wood as a building material — utilizing renewable resources.
- Many Pella products are made from wood — a renewable resource.
9. Embodied energy — the total energy it takes to produce the product.
- Wood products have a much lower embodied energy than competitor materials such as aluminum, for instance. When compared to a window of the same size, aluminum uses eight times the embodied energy of wood over a 40-year period.
10. Certified wood — there are several wood certification systems available, the most well known being FSC (Forest Stewardship Council) and SFI (Sustainable Forestry Initiative). Most of the well-known certification systems are developed and used with the same key purpose in mind, which is to practice sustainable forestry. How they do this will vary.
- Wood is the only renewable source for any building material commonly used today. (Source: AIA Environmental Resource Guide)
- Net volume of softwood on U.S. forestlands was 12 percent greater in 1997 than in 1953. (Source: Forest Resources of the United States, 2002)
- 80 percent of Pella Corporation’s wood supply comes from 3rd party certified forestry.
A budding green example — Pella® Impervia®
Pella® Impervia® windows and patio doors, made of patented fiberglass composite materials, are proof that energy efficiency doesn’t only come in the form of wood and doesn’t apply only to new homes. Pella® Impervia® products support the green movement and contribute to LEED projects in several major categories.
Here’s how this high endurance product from Pella is the perfect solution for a home or business while supporting the green movement:
Energy, atmosphere
- Pella’s patented, five-layer, engineered fiberglass composite, Duracast®, offers low expansion and contraction rates that help ensure a consistent bond between sash and glass and a weathertight fit between sash and frame.
- Duracast® offers resistance to condensation and superior thermal comfort to those seated near windows.
- Pella® Impervia® products with Low-E insulating glass are designed to provide energy efficiency that will save money by lowering heating and cooling bills.
- These high endurance products are NFRC-certified and meet or exceed ENERGY STAR® requirements in all 50 states, helping save on energy costs.
- All Pella® Impervia® products are tested for compliance with WDMA Hallmark Certification testing standards.
- Pella® Impervia® windows are highly energy efficient, with total unit U-values as low as .28 and air infiltration rates as low as 0.1 cfm/sq.ft. Virtually every unit is factory-tested for air infiltration rates when manufactured.
Materials and resources
- Product packaging contains recyclable cardboard and stretch wrap.
- Pella® Impervia® products have a 21 percent post-industrial recycled content by weight.
- Duracast’s factory-applied powder-coat finish is extremely hard, scratch resistance and does not corrode, which helps windows and doors last through time.
Environmental quality
- Pella® Impervia® windows and doors don’t need painting. They arrive with a durable powder-coat paint finish, an environmentally conscious coating that does not emit any significant air pollutants found in liquid paint finishes, which are typically made with greater than 50 percent solvents which evaporate into the air during spraying and drying.
- Duracast® features a factory-applied powder-coat finish, virtually eliminating VOCs (Volatile Organic Compounds) during the paint process, and overspray of paint from the powder-coating process can be collected and used again and again.
- Pella® Impervia® offers a variety of operable window and door types for fresh air ventilation.
* Superior NFRC U-values and SHGC ratings
Sources:
GreenSpec is a BuildingGreen product information service. It contains detailed listings for more than 1,800 environmentally preferable building products with descriptions, manufacturer information, and links to additional resources. All listings are screened and written exclusively by staff. Pella does not pay for its listings and did not purchase an ad to be included in this directory. Pella’s Designer Series classification in GreenSpec is:
Pella's Designer Series® wood windows and doors are available with an interior hinged glass panel and with an exterior panel of either single-pane or double-pane argon-filled, low-emissivity glazing. The exterior is clad with recycled aluminum finished with a baked-on EnduraClad® coating. These windows are made with 21 percent post-industrial recycled content, per the manufacturer. A number of Pella windows have unit U-factors at or below 0.25.
Other useful sources: