By: Meghan McDermott, Co-Owner and Architectural Engineer at High Performance Building Solutions
We’ve all heard the trend of school buildings moving towards more Science, Technology, Engineering and Math (STEM) education and development. But, have you ever thought “How are those topic areas being integrated into the buildings that students learn in, that teachers work in or that parents plan in?”
As a parent, I’m certainly interested in ensuring that my children and their classmates have safe, comfortable and healthy places to learn when they aren’t at home; and that our limited education dollars are spent on efficient building systems. As an expert in building science with 15 years of experience crawling in, over and through many school buildings in North Carolina and across the country, I can tell you, many of our school buildings need a lot of work.
Two prominent (and often related) issues that we encounter in school buildings are moisture intrusion and heating and air systems performance. As evidenced by the large number of buildings with moisture problems, avoiding moisture in buildings is not as simple as it may seem. Fortunately, there is a whole industry that I work in – Building Performance – that uses the science of how buildings work to design new school buildings to perform well and to fix problems in older schools.
First, moisture intrusion. All of the tiny little connections between walls, windows, doors, mechanical equipment, roofing systems and many other places can allow moisture – in the form of bulk water or humid air – to leak or travel to places where it doesn’t belong.
To identify these issues, building scientists like myself will perform a variety of inspections to identify areas of air leakage, bulk water intrusion, or areas where condensation is occurring. The key to the inspections is to identify the source of moisture, how it moves through the building and the characteristics of any damage sites. If mold or other air quality concerns is suspected indoor air quality testing may be conducted.
Understanding and resolving the root cause of these issues is important. What seems like a roof leak may be condensation on the roof decking – repairing a roof won’t solve that problem. Moisture problems don’t go away by themselves; they can cause hundreds of thousands of dollars’ worth of damage over time and yes, can cause health, comfort and safety issues in our school buildings. That’s why they are important to inspect and correct – no matter how small they may appear to be.
A second prominent issue that we encounter in school buildings is heating, ventilation and air conditioning (HVAC) system performance. Although not obvious to all, one function of air conditioning is to remove humidity from the air. However, too often school districts depend on their HVAC systems to dehumidify the interior without considering the root cause of the excess humidity at the source.
When performing inspections of school buildings, we frequently see elevated humidity levels that are beyond the capacity for the HVAC system to resolve. Turning up the air conditioning system to “dry out the building” leads to a cold but clammy building. This is seldom a good solution, unfortunately, excess moisture in the air is most commonly the result of uncontrolled infiltration. School HVAC systems are not sized based on the actual infiltration rate of a building but on a default infiltration rate in the modeling software. The installation of the building’s air barrier system – part of the envelope control layers –greatly impacts the performance of the HVAC system. Often, we see a “re-heat” system or the addition of other dehumidification equipment installed to combat the elevated humidity levels, but doing so raises energy cost and without addressing the root cause.
Like the issue of moisture intrusion, improper usage of an HVAC system can result in air quality issues and an uncomfortable and sometimes unhealthy environment. A building scientist like myself will test for these conditions, inspect common problem areas and recommend solutions that can solve them permanently.
While I would love the opportunity to diagnose and repair all of the performance issues in North Carolina’s school buildings, there are just too many and schools are facing budget constraints that don’t allow them to fund diagnostic testing or repairs for deferred maintenance issues. However, in some cases when these issues result in visible mold growth, I’ve seen entire HVAC systems replaced with no understanding that the root cause is an excessively leaky building and the repair scope of work fails to address the root cause of the mold growth.
What school building operators and maintenance staff can do is to – when able – seek out certified and trained auditors, installers and maintenance contractors that have been through rigorous training programs that may include local workforce training programs. The cheapest contractor is not the best option in cases of building science. Experts who understand the building as a total system can help assure that the best solutions are pursued, and the biggest problems are prevented.
Financial constraints in school districts do often lead to low bids winning out versus the best qualified bid. Those circumstances are unfortunate but all too commonplace. Perhaps North Carolina will move on initiatives to improve this process in the future – I hope they do.
Many remediation contractors – the ones who are likely your first call when you encounter a mold issue – are not adequately trained in building science. Such contractors, that only treat and remediate the symptoms, are typically not qualified to diagnose the root cause. Building science is a practice that includes diagnosing and recommending solutions that address the true source of the building system issues, which may not be the simplest or easiest one to diagnose. Just because you caulk a hole doesn’t mean that you have stopped a leak. Water has a knack for causing all kinds of problems in buildings; if one pathway is sealed up, it will find another until It is stopped at the source… trust me!
In cases of unqualified or inexperienced contractors, I’ve seen unfortunate situations where contractors or maintenance staff will overtreat the symptoms, resulting in more damage and lingering issues than there were originally. Again, building science teaches us to understand the source issue and create solutions that consider the building and how it works as a whole, not just a single part.
For contractors looking to improve their understanding of building science and expand their services into much needed markets like public schools across North Carolina, I suggest becoming a member of North Carolina Building Performance Association (NCBPA), where I serve as the Board Chairman. NCBPA is a not-for-profit association that supports our industry by providing training opportunities for installers, architects, commissioning agents and contractors of all types to help improve the durability, resilience, energy efficiency and performance of all North Carolina buildings, including schools.
For building owners and operators looking for more education, NCBPA operates a great website at www.BuildingPerformanceNC.org that includes a tab for school buildings. Go there to find some helpful information to orient you towards understanding your building’s problem and possible solutions. When ready, NCBPA can connect you to a building scientist like myself that can help you address building performance issues.
Lastly, schools aren’t the only places where our children may face unhealthy building environments. At home, similar conditions with improper HVAC systems, water intrusion, air leakage and more can cause issues that may result in asthma and other health concerns. Homeowners and renters alike can find helpful information on NCBPA’s residential website at www.HomeEnergyNC.org. Use that website to understand what issues you may be facing at home and then contact NCBPA to find a qualified member company in your area.
For more information on Meghan McDermott’s work at High Performance Building Solutions, visit their website at www.hpb-solutions.com or click here for a recent article in Building Enclosure Magazine featuring an interview with Meghan.