New York State Energy Code - Airtight, Tested Right:
What is a Blower Door (Building Air Leakage Measuring Equipment)?
A Blower Door is a portable, calibrated fan that mounts in the frame of an exterior door. The fan is adjusted to create a small pressure difference, normally -50 Pa between the interior vs. the exterior of the building. The exterior is the reference point. So, the interior is made to be more negative causing outside air wanting to enter (infiltrate) the building thru any unsealed cracks & openings (penetrations). It exits the building thru the fan. That is, air is “sucked” out of the building so it wants to come in thru the penetrations.
The test must be observed by the Approved Agency (Architect or Physical Engineer[PE]) responsible for the DoB form, TR8: Technical Report, Statement of Responsibility for Energy Code Progress Inpections. for Air Sealing and Insulation. These results must be reported to the DoB.
Envelope Air Leakage Testing – Technical Information
NYCECC paragraph R402.4.1.12 specifies the requirements for a Mandatory Air Leakage Test of new residential Buildings or dwelling units. The requirement specified in both NYC and NYS. It has been implemented because proper Air Sealing can reduce total energy usage in a building by as much as 11% according to the US EPA.
- The test is commonly known as Blower Door Test. It must be performed prior to the NYC Department of Buildings (DoB) sign-off. It may be conducted at any time after the building is enclosed and all penetrations to the building envelope (surfaces contiguous to ground or exterior) have been sealed. Preferably, a preliminary test should be performed prior to final covering of the interior walls (e.g. before wall board is installed) so that gross leaks can be remedied before they are made inaccessible by finishes.
- The test results cannot exceed three (3) air changes per hour at 50 Pa (pascals). The test must be performed in accordance with ASTM E779 or ASTM E1827.
- There are some optional (alternate) procedures allowed for buildings with two (2) or more dwelling units. These procedures are covered in paragraph R402.4.1.3 of the code. This test is also designated as IA7 or IIA7 on the DoB TR8 form