Opening the door to high performance in extreme temperatures

by nithya_caleb | July 13, 2018 2:00 pm

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By Siva Davuluri

Canada is famous for many things, including hockey, maple syrup, and stunning landscapes. Its large temperature swings and harsh winters are as well-known as Niagara Falls. Even temperate southern cities like Toronto see average monthly temperatures drop more than 25 C (77 F) between peak summer months and the dead of winter. This number grows to more than 30 C (86 F) for cities like Québec, Montréal, and Edmonton, and nearly 35 C (97 F) for Winnipeg.

Regardless of location, air leakage and air exchange are two of the biggest issues facing architects, designers, and facility managers when it comes to specifying commercial rolling doors for conditioned warehouse spaces across the country. This is a direct result of a larger trend toward increased energy efficiency for industrial and commercial buildings along with tougher standards such as Canada Green Building Council’s (CaGBC’s) Leadership in Energy and Environmental Design (LEED) v4.

After all, the longer a door is open and the weaker the seal around it is, the higher the likelihood of air exchange and thermal loss. This effect is magnified when temperatures dip below the freezing mark.

However, recent developments in high-performance doors can contribute to more energy efficient construction with a combination of operational, maintenance, safety, and sustainability benefits, thereby preventing:

• heat exchange through prolonged opening of the door;
• thermal loss due to inadequate insulation when the door is closed; and
• maintenance downtime because of complex service needs.

To improve energy efficiency and save time and money as well as meet increasingly stringent environmental laws and regulations, industry professionals are turning to high-performance doors.

The Door and Access Systems Manufacturers Association (DASMA) defines a high-performance door as “a power-operated rolling, folding, or sliding non-residential door, generally characterized by either 100 or more cycles per day or 20 or more inches per second opening speed, and typically made-to-order and/or designed for higher durability, and/or designed to break away due to equipment impact.”

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Code-exceeding energy efficiency

The American National Standards Institute/The American Society of Heating, Refrigerating and Air-Conditioning Engineers/ Illuminating Engineering Society (ANSI/ASHRAE/IES) 90.1-2016, Energy Standard for Buildings Except Low-Rise Residential Buildings, the 2015 International Energy Conservation Code (IECC), and the 2015 International Green Construction Code (IgCC) are important energy saving mandates for commercial and industrial facilities.

In the near future, it is likely the definition of a well-designed building will include the attainment of net zero-energy usage.

Products combating air leakage offer tools to achieve conservation goals by reducing heat exchange and increasing thermal efficiency, thereby decreasing the environmental impact and energy usage of the building.

Many design and building professionals do not realize the latest code requirements identify stringent, non-negotiable standards for acceptable air leakage, defined at a constant value of 0.25 L/s-m² per the the Building Energy Performance Compliance Path, sub-section 8.4 of Division B of the National Energy Code of Canada for Buildings (NECB).

Contrary to popular opinion, these are not optional standards to be “greener.” The new regulations are mandatory, and a trade-off path to approval is not available. Further, products must have third-party certification (e.g. Building Owners and Managers Association [BOMA] of Canada and the U.K. Building Research Establishment’s [BRE’s] Environmental Assessment Method [BREEAM]) to substantiate compliance.

Exterior rolling door manufacturers are developing products to meet these new performance goals.

In the past, rolling doors were selected for their space-saving benefits, security, reliability, and durability. Design professionals are now choosing them for their energy efficiency as well since some models meet or exceed ANSI/ASHRAE/IES 90.1-2016 and IECC’s air infiltration requirements with air leakage value of less than 0.01 cmm/m³.

Controlling air infiltration

Thermal resistance and air leakage are often inter-related. Key air leakage areas for a conventional rolling door are at the head and along the guides. Since metal has high conductivity, energy efficient doors with metal frames should include thermal barriers in the guides to reduce conduction. Frames without thermal barriers reduce the energy efficiency of the entire building envelope.

Doors designed with advanced perimeter seals, thermally broken frames, and insulation offer increased air infiltration control. Additionally, these perimeter seals can accommodate odd floor and wall conditions, including slopes, curbs, or rails, and doors can be designed to meet specific installation requirements to provide an energy efficient enclosure for new construction or retrofit projects.

Some rolling doors can decrease air infiltration by as much as 95 per cent, and manufacturers estimate savings of up to $1215 per door with a two-year return on investment (ROI) when selecting an energy efficient rolling door for the appropriate climate zone.

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How doors can increase productivity

Beyond air leakage and thermal loss in regions with extreme temperature swings, a door’s opening speed can directly relate to a client’s bottom line. For starters, productivity can increase significantly. A standard service door opens at about 203 mm (8 in.) per second. This can feel like an eternity to someone driving a forklift and waiting for it to open. Pausing, even for as little as 20 seconds, can end up costing hours and days of productivity in a 24/7 operation using a door for every pass-through. By contrast, high-performance doors can open as quickly as 610 mm (24 in.) per second—more than three times faster.

A client’s need for opening speed can be determined by factors such as:

• total opening height;
• frequency of opening;
• number of stalls for a parking application;
• number of fork trucks going through the opening;
• traffic patterns;
• equal flow of traffic throughout the day vs. rush hour traffic (if it is a heavily-used opening one wants to open it as quickly as possible to avoid traffic piling up); and
• placement of activation devices signalling the door to open (e.g. one can place the activation device far away so the door does not need to open quickly).

Low maintenance combats downtime

When a standard rolling door is run more often than recommended, its motor can overheat, and its components can wear out quickly, rendering the door unusable. Designed specifically for durability, high-performance rolling doors feature a spring-less design with fewer wear points. They are constructed to withstand heavy continuous use, as much as 100 or more cycles per day.

Maintenance on an inoperable door can be costly in its own right, but a door that does not work can also cause delays in a client’s ability to do business and cause employees to create workarounds. For example, when a door is out of service or closed for repairs, employees may need to spend extra time driving forklifts out of their way to use an operational door. This means more products must go through fewer openings.

As a case in point, consider a factory of 50 workers. If each employee takes an extra four minutes, multiplied by 50 people, this equals 200 minutes, or 3.3 hours per day. If this is a 365-day operation, the yearly impact is 3.3 x 365, or 1204.5 hours per year. If the average salary is $20 per hour, this translates to $24,090 in lost productivity.

Contributing to LEED credits

While no single product or material alone can earn LEED credit points—which can bolster a client’s reputation and provide assurance the building is designed, built, and operated the way it was intended—the design of a building envelope has the largest impact on the structure’s energy performance. As part of an integrated design and construction strategy, the use of high-performance rolling doors contributes to a number of environmental benefits, thereby helping architects obtain LEED v4 credits.

For example, insulated doors featuring polystyrene board, polyurethane foam, and other materials provide many sustainability fundamentals for commercial building closure solutions. These contribute to greener, more energy efficient, high-performance construction across a number of sectors, as well as greater occupant health and comfort thanks to decreased heat transfer, increased performance, and less downtime from maintenance.

Some of the potential benefits of energy efficient rolling doors include:

• greater thermal resistance value (R-value);
• reduced energy costs due to decreased air infiltration;
• chlorofluorocarbon- (CFC) free insulating process (CFCs destroy the Earth’s protective ozone layer);
• the use of recycled content, which may be included in the curtain, bottom bar, hood, guides, the shaft, and the brackets of the doors; and
• lack of volatile organic compounds (VOCs).

This type of door also contributes to specified wind load durability.

Qualifying LEED v4 credits for rolling doors can be applied in the following categories:

• Energy and Atmosphere (EA) Credit, Optimize Energy Performance (up to 20 points).
• Materials and Resources (MR) Credit, Building Life Cycle Impact Reduction (up to six points).
• Indoor Environmental Quality (EQ) Credit, Low-emitting Materials (up to three points).

One can also earn up to five points under the Innovation Credit.

Choosing an insulated rolling door as an innovative construction envelope element could also contribute up to four points under the Regional Priority Credits (RPCs) addressing geographically specific environmental, social equity, and public health priorities.

Conclusion

From warehouses and fulfillment centres to fully-conditioned areas and tiered facilities, high-performance rolling doors promise significant savings and low lifetime cost, without sacrificing usability. While they may have higher initial costs compared to a standard rolling product, the savings in energy related expenses combined with the cost to repair and replace parts over the life of the building will far surpass the initial investment in the author’s experience. For countries like Canada that are prone to temperature extremes from season to season, these savings are magnified.

[4]Siva Davuluri is director of product strategy for high-performance doors at CornellCookson. Davuluri has more than a decade of experience in design, development, and commercialization of new products. He has a master’s degree in mechanical engineering from North Dakota State University and an MBA from Cornell University. Davuluri is also a member of the technical committee for high-performance doors at Door and Access Systems Manufacturers Association (DASMA) International. Davuluri can be reached via e-mail at siva.davuluri@cornellcookson.com[5].

Source URL: https://www.constructioncanada.net/opening-the-door-to-high-performance-in-extreme-temperatures/

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