|
What is air leakage & what impact does it have?
Computer modelling can demonstrate potential energy
savings that can be achieved by reducing building
envelope air leakage. These examples are based on
a single-celled industrial unit with an internal
building temperature of 16°C & a leakage rate of 20m3/hr
per m2 @ 50Pa for a leaky building, and 5.0m3/hr per m2 @
50Pa for a low leakage building.
| Energy air leakage requirement for 5,000m2
building |
| For a leaky building:
20m3/hr per m2 @ 50Pa |
|
| Maximum natural air
exchange rate due to leakage |
0.55 ACH |
| Estimated air leakage
energy requirements |
111,725 Kwh
per annum |
| For a low-leakage building:
5.0m3/hr per m2 @ 50Pa |
|
| Maximum natural air
exchange rate due to leakage |
0.13 ACH |
| Estimated air leakage
energy requirements |
27,932 Kwh
per annum |
| Difference |
83,793 Kwh per annum |
| Energy air leakage requirement for 10,000m2
building |
| For a leaky building:
20m3/hr per m2 @ 50Pa |
|
| Maximum natural air
exchange rate due to leakage |
0.5 ACH |
| Estimated air leakage
energy requirements |
221,757 Kwh
per annum |
| For a low-leakage building:
5.0m3/hr per m2 @ 50Pa |
|
| Maximum natural air
exchange rate due to leakage |
0.12 ACH |
| Estimated air leakage
energy requirements |
55,441 Kwh
per annum |
| Difference |
166,316 Kwh per annum |
Building air leakage testing & minimising air leakage not only significantly
reduces the energy consumption and CO2
emissions, but can also reduce the capital cost of heating
and ventilation plant due to the potential for plant
downsizing. |
