Mitigating Whole Building Air Leakage
Seals Supporting ASHRAE 90.1 Compliance
ASHRAE, the American Society of Heating, Refrigeration, and Air-Conditioning Engineers, aims to provide “a healthy and sustainable built environment for all,”. Their standard 90.1 is critical in achieving this vision. ASHRAE Standard 90.1 provides recommendations for energy-efficient building design and is used as a baseline for codes and standards around the world.
A critical concern of 90.1 is whole building air leakage. The 2022 standard sets maximum air leakage rates, typically around 0.40 cfm/ft² at a pressure of 0.3 in. w.g. for most new buildings. This level is intended to reduce unintended air flow, leading to improved thermal control and energy savings.
Insulation, vapor barriers, thermal breaks, and proper installation and specification of fenestration and HVAC systems all play a major role in creating an airtight building. But another critical, and often overlooked component, is properly designed and installed seals.
HVAC Seals Improve Energy Efficiency
ASHRAE 90.1 requires that all ductwork, especially in conditioned spaces, is sealed to specified leakage classes. There are a variety of ways to seal ductwork: mastic sealant, tape, latex sealant, and rubber gaskets are all commonly used options. Each option has unique pros and cons, but at Reed, we recommend thermoplastic rubber gaskets, as the
y provide maximum sealing and a clean visual aesthetic without the mess of mastic or the labor of taping.
In addition to sealed ductwork, other HVAC components must meet stringent leakage standards to comply with ASHRAE 90.1, damper seals are another way to ease compliance Damper systems on their own help to control the flow of air in or out of a room or building, but by implementing blade and/or jamb and side seals the system will become airtight.
Fenestration Seals Reduce Whole Building Air Leakage
ASHRAE 90.1 also specifies that all windows, doors, skylights, and façade systems must be sealed effectively to limit air leakage and infiltration. There are specific leakage requirements for each application type and typically range from 0.10 to 1.00 cfm/ft2. Air leakage can be controlled in a variety of ways, but one of the simplest methods for sealing fenestration is by using proper fitting seals made with high quality material.
Poor fitting glazing gaskets, aside from posing a structural risk to the fenestration system, can create gaps that allow air to escape. Depending on the application, a standard profile shape may suffice, but when in doubt, a custom engineered solution ensures proper fit and function.
Additionally, material selection is critical when selecting glazing gaskets. Resistance to compression set, UV exposure, temperature changes, chemicals, and salt water all can be paramount in selecting a seal, as material degradation can create voids in the barrier that allow air leakage.
Why Partner with Reed Rubber?
Design Support
To ensure proper fit and function, our team of engineers carefully review every detail of your application. Tolerance stacks, part application interface, profile design, and durometer(s), are all considered when consulting on a custom designed part. Learn more about our design support capabilities.
Material
At Reed, we extrude our parts with Thermoplastic Vulcanizate (TPV) due to its superior durability, performance, and sustainability. TPV has low compression-set, resists UV radiation and weathering, and is fully recyclable, including post-consumer recycling. Discover the TPV benefit.
Quality Control
Details matter. That is why every part produced at our Saint Louis, MO facility undergoes the same stringent quality inspection. Parts are compared against tolerances using automated visual inspection and are fit tested on every run.
If you need help designing or selecting seals, reach out to our team!