Combating building pressure at the door

Energy efficiency
Door closers combat building pressure’s effects on energy costs by decreasing airflow through an opening and improving total cost of ownership. Specifying the correct door closer reduces airflow and energy loss through exterior openings of a building and results in long-term energy savings.

Buildings are designed to allow a small amount of airflow to exhaust from the structure in order to keep dust, smoke, and odours outside. However, this process requires the HVAC to effectively overcome the fluctuations in pressure caused by wind, outside temperature, building design, and various other factors. If the system is unable to do so, it can lead to a high pressure differential, which may ultimately result in higher energy costs, lowered indoor air quality (IAQ), building deterioration, and door hardware damage.

Properly closed openings also prevent the infiltration of warm, humid air into a facility during warmer months. If a door is left ajar, the interior becomes subjected to conditions ideal for mould growth, poor IAQ, and structural deterioration. In colder months, similar problems can develop, as positive pressure may force warm air into the building envelope, causing moisture to condense on cold surfaces inside the building.

“Energy Cost Savings Using an Effective Door Closer,” a recent joint study conducted by Purdue University, the Chinese University of Hong Kong, Tianjin University, and this author’s door hardware manufacturing company examined the potential heating and cooling energy cost savings from using an effective door closer. Using the closer under different pressure differentials in different climate zones with a spring setting of Size 1, the study found by installing an effective closer on exterior doors, companies could save as much as $2134 per door in annual heating and cooling costs.

The study also found as pressure differentials increase, so do facility costs. Areas with extreme climates, like Edmonton, will see the highest potential for savings. The larger the temperature gap, the greater the indoor-outdoor pressure differential—resulting in greater airflow through the door. More energy is needed to condition the additional air flowing through the opening and, therefore, energy costs will be higher.

Similarly, the U.S. National Institute of Standards and Technology (NIST) reported annual heating and cooling energy costs could be reduced by three to 36 per cent, depending on the climate zones, if the target airtightness levels were achieved. A door closer that securely shuts and latches the opening can help significantly.

Conclusion
Considering the impacts of building pressure early in a project can substantially improve long-term savings. By specifying an effective door closer upfront, architects can reduce airflow throughout a facility to improve sustainability, energy costs, and the building’s longevity, as well as overcoming safety and security risks.

Alan D. McMurtrie, DAHC, is a certified, distinguished architectural hardware consultant who is a member of the Door and Hardware Institute (DHI). He has 32 years of experience in the openings industry—specifically, with specifying architectural hardware for design professionals. Successful healthcare projects McMurtrie has specified in Ontario include North Bay Regional Hospital, Sudbury Regional Hospital, Meno Ya Win Health Center, and Toronto Rehabilitation Institute. McMurtrie can be reached via e-mail at alan.mcmurtrie@allegion.com.