As the name suggests, air testers are specialised pieces of equipment that are designed to test the quality, ‘tightness’ or escape of air in a number of industrial applications. Current regulations mandate three different types of air testing take place on a construction site:
Air tightness testing
Which seeks to identify the permeability of a building by measuring total air loss through the fabric. These tests are generally carried out by testing experts, and are used to identify areas of uncontrolled ventilation, and work out a new build energy rating.
Air quality testing
Which is frequently carried out on industrial or construction sites, and aims to measure the presence of harmful pollutants in accordance with COSHH guidelines.
Air testing of pipes
Which is generally carried out on drainage systems, and seeks to identify any segments or joints that are facilitating pressure loss in the system as a whole.
Generally speaking, the equipment that’s needed to perform each type of air test is quite different, although the fundamental principles are the same.
Air quality testing is carried out using handheld monitors, with a probe that’s designed to detect the presence of any pollutants, and feedback a reading that quantifies the general air quality in a given area.
Air “tightness” testing is carried out with the aid of several large fans, a pressure monitor and door seals. The building that’s being tested is generally “sealed up” by closing off any ventilation, and then pressurised so that air loss can be measured over time.
Air testing drainage pipes
Although it follows the same principle, the air testing of pipes and sewers is a different story altogether. This work must be carried out to ensure that there is no pressure loss before a given drainage or mains water system is fully sealed, as retroactively addressing pressure loss due to flaws in piping can be very expensive.
In fact, if a drainage system is later found to be leaky, the construction crew often has to excavate, disassemble and rebuild the entire system from scratch to ensure that the flawed segment is removed.
To make sure that this situation does not occur, pressure testing is normally conducted as the system is being built, rather than at the end. It’s best practice to air test every three to five pipe-lengths, and then again when the system is fully installed, but before backfilling commences.
To test the system, a length of pipe is normally sealed off using a specialised stopper or, in difficult conditions, an inflatable air bag. Air is then pumped into the pipe via a valve, alongside a small amount of water. The pipe is then left for a period of minutes, and any change in the water level is measured in order to calculate the total amount of pressure loss over time.
The equipment to carry out these pressure tests is relatively specialised, and it is important to ensure that a good quality of product is used to guarantee that test results are fully accurate. Because building regulations now specify that tests like this should not be carried out in reduced access environments, it is also possible to buy remote air testing kits.