Building envelope testing is the process of checking for air, water, or thermal leaks in the interior or exterior of a building. It is necessary to ensure durability, energy efficiency, and comfort.
The opportunity exists for gaps and leaks to occur in multiple locations throughout the building envelope. Pipes, walls, floors, windows, sealants, and other areas can have defects or develop issues due to improper installation. These factors can lead to potential issues and energy inefficiencies, such as loss of heat, or the leakage of water or air. An estimated five percent of all energy produced yearly is lost by leaking out of buildings.
Without performing adequate building envelope testing, these gaps and leaks may be unnoticeable but still can cause potential harm to occupants, and damage to the building, along with increased energy expenses and costly repairs for the owner.
In this article, we will describe the most common building envelope tests, as well as explain the benefits of building envelope testing.
Water infiltration testing
Water infiltration testing measures the extent to which the soil in and around your building can absorb water. It gives you a sense of how fast water will move through the foundations of your building site during strong rains.
This is an important test because water absorbing too quickly or too slowly can spell disaster for a building. Low water infiltration can lead to ponding and flooding in and around your building when it rains. High water infiltration could lead to marshy conditions and an unstable foundation.
The way in which experts measure water infiltration is by digging a hole and filling it with water. By measuring how fast the water level drops, you can measure how porous the soil is.
Air leakage testing
Air leakage testing measures the extent to which a building is airtight. This is important for discovering drafts and other air leaks in your building, which could accumulate significant energy costs over time.
One common technique for air leakage testing is the blower door test. In this test, a fan is mounted into an open-door frame with a device called a blower door. The fan is then turned on, blowing air outside, and depressurizing the building.
Based on the difference between the amount of air moved by the fan and the pressure inside the building, the test will show how much air is lost due to leakage through the building envelope.
Glazing system performance tests
It is important to test the exterior façade of the building, especially the glass of the doors and windows. These areas can be the most fragile parts of the building envelope, and typically can be the source of gaps and holes.
Factors to consider include water tightness, wind resistance, and air permeability.
Testing for specific components of the building exterior is like that for the building as a whole. A pressurizing or depressurizing device is attached to the door or window, and leakage can be measured by the difference in pressure.
Before installation, lab testing involves physical mockups to simulate real-life conditions under stress. QA testers also use virtual modeling for computer tests.
At Giroux Glass, we conduct quality assurance and testing through a combination of lab testing, computer modeling, and field monitoring. We also perform thorough visual tests post-installation to check for cracks, gaps, and misalignment. Read more here about commercial glass and curtain wall testing procedures.
Thermal performance tests
Thermal performance tests measure how much your building envelope insulates the interior of your building from external temperature changes. There are several variables which can be measured this way:
- Thermal transmission, or the rate of heat transfer through the building envelope.
- Thermal resistance, the amount by which your building resists changes in temperature.
- Thermal conductivity, how easily heat can transfer through the building envelope.
These tests are crucial for saving money on energy bills. Discovering points of weakness lets you adjust the thermal insulation for maximum effectiveness.
One quick test of this sort is using a thermal camera, which can quickly spot points of unusual temperature gradients. These specialized tools capture information on heat levels and movement in real-time. By examining the photo or video output from a thermal camera, you can pinpoint exactly where energy is leaving the building.
Acoustical performance tests
Acoustical performance goes both ways. Professionals measure how much sound gets blocked from coming in from the outside of the building, as well as how much sound gets blocked from coming out.
The test is simple: create noise on one side of the building envelope to a certain decibel measurement. Then measure how loud it is on the other side. The difference indicates the ability of the building envelope to block sound.
With this test, you can measure the Sound Transmission Category, or STC rating, of glass when it’s a glazing component of the building envelope.
Structural strength and durability tests
Having a strong and durable building envelope is critical, as the strength and durability of a structure will ensure the safety of its occupants.
Safety standards in this regard do vary from place to place. A building in San Francisco must adhere to local building codes for earthquake resistance, while a building designer in Florida has to follow local requirements for resisting strong winds caused by hurricanes.
Since we cannot summon an earthquake or hurricane at will, testing of building strength must be done indirectly. Individual building components, such as glass and wood, can be tested for adequate strength.
Additionally, the building can be examined thoroughly for cracks, tears, and other signs of structural defects. These examinations should be conducted regularly and problems dealt with immediately.
Benefits of building envelope testing
Testing the building envelope for flaws offers several benefits.
- Building envelope testing ensures that building materials are up to code and meet safety standards. Building materials could have flaws for a variety of reasons, including inadequate quality control or mishandling after production
- Building envelope testing improves energy efficiency by identifying potential sources of air leakage or heat transfer. A simple check with a thermal camera can quickly pinpoint locations where heat is escaping.
- Testing allows for the optimization of insulation configurations and design features. Again, simple thermal performance and air leakage tests can show where insulation is being used effectively and where it is not, allowing for reconfiguration.
- Testing helps contractors understand how various construction elements interact with each other, such as walls, floors, ceilings, windows, doors, and more. A building is a complete ecosystem of objects which interact with each other in complex ways.
- Testing maximizes comfort levels in buildings due to improved temperature control. Everyone has had the misfortune of being in a room with a draft before, and proper building envelope testing ensures that drafts are found and rooted out to ensure the ability to effectively control the temperature.
- Testing enhances the durability and structural integrity of the building envelope. A structure is only as strong as its weakest link. Building envelope testing finds the weakest points in the structure, so that they can be dealt with.
- Testing reduces operational expenses incurred from heating and cooling expenses. Many buildings have hidden flaws in their envelope that can cost thousands of dollars in energy bills every year.
- Ultimately, building envelope testing saves costs, if potential issues are identified before they necessitate expensive repairs later.
Conclusion
Building envelope testing is crucial for optimizing your building in terms of heating, cooling, durability, and comfort. It is a process that checks for all related issues so that they can be addressed.
Giroux Glass specializes in installing glass and metal on commercial building exteriors. We carefully examine and test every piece of material we install.
Contact us for more information about how our glazing experts can help to ensure that your building performs at its optimal levels.