About Us » Services » Whole Building Air Testing

Whole Building Air Testing

In the modern world of heightened energy consciousness, the rate at which building interior air can be exchanged with exterior air has become a matter of concern and the subject of various standards worldwide.  This is because the air carries heat, so a less leaky building can be more comfortable for the occupants, can require less heating or cooling capacity and consume less energy.

In our region we have the added problem of warm humid air on the outside laden with moisture, and cool dry air on the inside.  Warm air carries much more moisture than cool air, and the difference in the partial pressures of the moisture vapour in the air causes the moisture to try to travel towards the cool dry air wherever there is a path.

The test consists of mounting a fan or fans in external doorways (according to the fan capacity and the building size).  The pressure in the building is either decreased or increased to the relatively low pressure of 50Pa (gauge, or differential pressure relative to the outside), and the rate of air flow measured.  Prior to the test a number of preparations are made including turning off the HVAC system and sealing any permanent uncontrolled ventilation openings, etc.

Criteria for the test are given by ATTMA (The Air Tightness Testing and Measurement Association) in their Technical Standard 1, as follows.

 

Type Air Permeability
  M3/hr.m2 at 50 Pascals
  Best Practice Normal
Offices

  Naturally Ventilated

3

7

  Mixed Mode

2.5

5

Air Conditioned/Low energy

2

5

Factories / warehouses

2

6

Superstores

1

5

Schools

3

9

Hospitals

5

9

Museums & archival stores

1

1.5

Cold Stores

0.2

0.35

Dwellings

  Naturally ventilated

3

9

  Mechanically ventilated

3

5

 

In this table, the ˜Normal’ criteria are the relatively relaxed standards of the Building Regulations.  The allowable leakage is based on the area of the external envelope, defined as the area of the walls, roof and ground floor slab.

 

Contact our Projects Department for More Information »

 
 
credentials image
credentials image
credentials image
credentials image
credentials image