Enclosure - CLI Group 2017

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Enclosure

Building Performance


Building Enclosure defects can be expensive to correct, difficult to diagnose and can leave your facility vulnerable to issues such as indoor air quality problems. C.L.I. has worked on many area buildings that are suffering from such problems. In many of these cases, in addition to problems in design and construction, building owners are also faced with expensive mold remediation projects, damaged structural components and litigation.

C.L.I. Group, LLC is a member of the Building Enclosure Council (BEC)



Has Your Building Experienced...

  • Odors of unknown origin?

  • Damp carpeting near exterior walls?

  • Stains or discoloration on exterior walls?

  • High energy costs?

  • Rusted steel framing at doors and/or windows?

  • Moisture stains on ceiling tiles?

  • Failed waterproofing?

  • Roof leaks?


If you answered yes to any of those questions, you may be experiencing building envelope, drainage or pressure problems in your building. Left unattended, building envelope deficiencies can cause significant amounts of damage before being discovered, including environmental hazards. The problems above often worsen due to misdiagnosis. It has been our experience that all too often, building owners spend tens of thousands of dollars trying to find solutions to many of the above problems without getting any results. So what is the problem? The problem is short-sightedness. Building owners call roof contractors, HVAC contractors, plumbers and others to look for an answer. While such specialty contractors may work in certain circumstances, they will be unsuccessful in others. Why? Because they come onto the project site with preconceived notions about the problem and that brings a bias into diagnosing the problem. They see the problem from their standpoint only, because they have services and equipment to sell.

In order to be successful in difficult cases, the ability to diagnose the problems will come from a "third party" consultant. This consultant should be a building scientist or other multi-disciplined professional with no interest in selling a fix. This allows the consultant to evaluate the problem using a "holistic" approach. The consulting firm you choose should be multi-disciplined so that the building can be tested and diagnosed using this "holistic" approach. After all of the parties perform their diagnostics on the building, they can bring together to find the problem and the solution.  

“Despite common assumptions that envelope air leakage is not significant in office and other commercial buildings, measurements have shown that these buildings are subject to larger infiltration rates than commonly believed. Infiltration in commercial buildings can have many negative consequences, including reduced thermal comfort, interference with the proper operation of mechanical ventilation systems, degraded indoor air quality, moisture damage of building envelope components and increased energy consumption.”

- Excerpt from the 2005 National Institute of Standards and Technology (NIST) report, Investigation of  the Impact of   Commercial Building Envelope Airtightness on HVAC Energy Use.


According to the National Institute of Standards and Technology (NIST) report, Investigation of the Impact of Commercial Building Envelope Airtightness on HVAC Energy Use, the inclusion of an air barrier system in four sampled types and sizes of building reduced air leakage by up to 83 percent. This represents a large reduction in current and future energy consumption and operating costs: potential gas savings of greater than 40 percent, and electrical savings of greater than 25 percent.


Below are photos from a recent project performed for a large church. When the C.L.I. Group became involved, all parties were under the assumption that the doors and windows were leaking, which caused wet carpets near exterior walls, mold and odors. Our diagnosis, after investigating was much different. The masonry exterior walls of the church were built with an inadequate drainage plane and flashing. The ductwork was in a drop ceiling and was excessively leaky, thereby de-pressurizing the conditioned spaces. The difference in vapor pressures from exterior to interior, the hygroscopic capacity of the exterior brick, solar radiation and poor drainage plane added to the negative room pressures WRT outdoor led to significant amounts of moisture and condensation forming in the wall cavities. The steel stud framing also acted as a thermal bridge which made the problem even worse in the winter. The result was deteriorated framing, water damaged drywall and sheathing, mold and other issues. This problem was allowed to manifest itself over months due to numerous misdiagnosis of the problems.

Below are photos from a recent project performed for a large church. When the C.L.I. Group became involved, all parties were under the assumption that the doors and windows were leaking, which caused wet carpets near exterior walls, mold and odors. Our diagnosis, after investigating was much different. The masonry exterior walls of the church were built with an inadequate drainage plane and flashing. The ductwork was in a drop ceiling and was excessively leaky, thereby de-pressurizing the conditioned spaces. The difference in vapor pressures from exterior to interior, the hygroscopic capacity of the exterior brick, solar radiation and negative room pressures WRT outdoor led to significant amounts of moisture and condensation forming in the wall cavities. The steel stud framing also acted as a thermal bridge which made the problem even worse in the winter. The result was deteriorated framing, water damaged drywall and sheathing, mold and other issues. This problem was allowed to manifest itself over months due to numerous misdiagnosis of the problems.

The case below is one of several we have recently been involved which have similar problems. In most cases, the building owners had already spent thousands of dollars trying to correct the problems with little success. Such problems can only be diagnosed and corrected using an "holistic" approach to the problems. Our team of professionals includes building science professionals, professional engineers, indoor air quality professionals and air and balancing experts that can evaluate the building in it's entirety. It is important to understand when trying to address such problems with one specialty contractor, that in such cases, changes to one system of the building will affect other systems of the building. Those not understanding this holistic approach to buildings can have good intentions, but can actually make the problem worse.

By measuring the performance of the building and it's systems. Our team understands these important interactions and also has the ability to verify the results. This building enclosure was modeled before opening to evaluate problem (condensation) potentials.




When beginning an investigation, it is important to understand the loading on the enclosure. This is important in formulating any hypothesis, before any modeling can be done, etc. The amount of annual rainfall and the hygroscopic properties of the facade helped us in determining how our investigation should proceed.

 

  • Recent Wall Cavity Investigations Involving Large Commercial Buildings (Church & Area Hospital)

 
 
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