This is achieved by the aforementioned insulation, sealants, and energy-efficient windows. Loose Building Envelopesīuilding envelope systems are defined in one of two ways: tight or loose.Ī tight building envelope allows very few air leaks. Good insulation in the walls, high-efficiency windows, and sufficiently sealed gaps increase the effectiveness of the envelope. So, what exactly makes up a building envelope? A building envelope is everything that separates the internal building from the external environment, including the roof, doors, windows, floors, and walls. It’s important to note that older structures weren’t constructed with building envelopes in mind, which explains why these buildings aren’t as energy-efficient as newer ones. Keeping heated or cooled air inside (and their respective opposites out) means less energy used and less money spent on heating and cooling.īuilding envelope technologies account for approximately 30% of the primary energy consumed in residential and commercial buildings these technologies affect many factors related to a building’s energy consumption, including lighting, ventilation, and the energy required to heat and cool the building. Similarly, during the summer months, the envelope keeps the cooled air inside and the hot air outside.īecause of this barrier, the building envelope plays a key role in a structure’s energy efficiency. In the winter, the building envelope helps prevent the transfer of heat from inside to outdoors. It’s like a shell - a barrier against the world outside of the building. Give Efficiency Matrix a call, should you have any queries about improving the performance of your building envelope.A building envelope is a seal of protection for the people and things inside a structure. It is expressed in cubic metres of air per hour that passes through each square metre of the building envelope (m3/h/m2).ĥ0Pa of fan pressure from a blower door or multiple blower doors is equivalent to approximately 32km/h winds onto all facades of a building. The building envelope permeability rate is a measure of the amount of air that “permeates” through gaps, cracks and large holes in the building envelope when driven by an external force such as the wind, a poorly balanced air conditioning system or the thermal stack effect (Chimney effect). Air leakage testing with Blower door testing.Īir leakage testing otherwise known as Blower Door Testing or fan pressurization testing allows us to test a building for air tightness scientifically, and produce a number which can be used to compare buildings, build quality. This is not a solution, and you should seek an experienced contractors advice who specializes in air tightness and the integrity of the building envelope. Some people assume that the airtightness layer is from the false ceiling, and some contractors may try to caulk ceiling tiles in, to improve the airtightness of the building envelope. The Air barrier and thermal barrier need to be thoroughly and consistently in contact with each other.
Increased ability to control internal humidity levels.Reduction in the size of HVAC/Air conditioning systems required.Reduction in the volume of air that requires conditioning which reduces heating and cooling costs.The benefits of reducing the permeability rate of a building envelope are: Pressure testing should be conducted with ceiling tiles removed, to allow air pressure to spread evenly behind the false ceiling. As an example, a commercial building with a metal deck roof and ceiling tiles would need to undertake remediation works behind the false ceiling to improve the overall performance of air tightness. The air barrier MUST also be accompanied with the insulation barrier as well. False ceilings and false floors are NOT where your air barrier is located. It’s important to understand where your air-tight envelope is located. Connectivity of the building to the ground is also considered outside. It includes the floor of the bottom floor, the walls/window facades and the ceiling of the top floor. The building envelope otherwise known as the air barrier is defined in the section of the building fabric that separates the inside air volume from the outside environment. However, in this article, we focus on the building physics side of the building envelope. Some people may have a different perspective of what the building envelope is, for example: It’s a very common question so we thought we might answer the question of “What is the Building Envelope?” and while we are at it, show you where it is generally located.