Intent
To minimize waste of energy caused by uncontrolled air leakage into and from conditioned spaces.
Requirements
Case 1. Single Family
Meet the air leakage requirements shown in Table 1 or Table 2. The rate of air leakage to outside must be tested and verified by a qualified energy rater.
Case 2. Multifamily
Meet the air leakage requirements shown in Table 1 or Table 2. The rate of air leakage to outside must be tested and verified by a qualified energy rater.
Meet the requirements for leakage to outside the conditioned envelope for each dwelling unit, unless the whole building can be entirely and sufficiently depressurized by a blower door(s).
Table 1. Points for reducing air leakage, in ACH50
| IECC climate zone | Points | |||
|---|---|---|---|---|
| 1–2 | 3–4 | 5–7 | 8 | |
| 4.25 | 3.5 | 2.75 | 2.0 | 1 |
| 3.0 | 2.5 | 2.0 | 1.5 | 2 |
Table 2a. Points for reducing air leakage, in cfm50 per sf envelope area
| Performance requirements IECC climate zone |
Points | |||
|---|---|---|---|---|
| 1–2 | 3–4 | 5–7 | 8 | |
| .195 | .16 | .125 | .925 | 1 |
| .1375 | .115 | .925 | .675 | 2 |
Table 2b. Points for reducing air leakage, in cmm50 per 100 square meter envelope area
| Performance requirements IECC climate zone |
|||||
|---|---|---|---|---|---|
| 1–2 | 3–4 | 5–7 | 8 | Points | |
| 5.94 | 4.87 | 3.81 | 2.82 | 1 | |
| 4.19 | 3.50 | 2.82 | 2.06 | 2 | |
ACH = Air changes per hour
cfm = cubic feet per minute
ELR = envelope leakage ratio
IECC = International Energy Conservation Code
sf = square feet
cmm = cubic meters per minute
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