Quite often air infiltration and exfiltration, i.e. uncontrollable air passage through hidden defects of windows, doors, wirings, pipes, coverings and steam insulation, is the reason for cold inside the house, condensate formation and subsequent growth of a mould, lowered humidity (over-dry air). While thermal losses through limiting structures, as a rule, are several times lower than the owner thinks.
There are special installations for determination of the leakage of air (BLOWER DOOR) - allowing to carry out the test for tightness. The Blower Door technology is a globally accepted methodology to examine tightness of a building allowing to measure air permeability and to identify places of latent defects in a structure.
The tightness test is a very effective decision to:
determine places of loss of heat of airflows inside a building;
check the quality of construction of a building before its purchase;
exert control over quality of the construction operations performed in the course of building construction.
The Blower Door system includes a powerful fan having several speeds. Speeds are regulated by means of the panel of settings, which is temporarily mounted in the external doorway. Some manometers are applied to determine the difference in pressure.
Tightness tests are made by the method of creation of the difference in pressure when by means of a fan mounted in the house door or window, in the building a "mini-vacuum" of 50 Pa is created. Thus air streams will flow inside through flaws of an insulating layer.
Test for tightness requires no special weather or temperature conditions and can be performed at any time of the year under any weather conditions.
When carrying out such an inspection some hours are required depending on the size of a building and complexity of its form.
The most effective performance of the test for tightness and the heat vision inspection is at a stage of construction and renovation as there is a possibility of correction of the found faults before completion of finishing works. At the same time quality of installation of windows, doors and a steam barrier is checked.
The heat vision inspection.
Performance of the heat vision inspection allows to diagnose:
faulty double-glazed windows, defects of installation of double-glazed windows;
faulty heat insulation of the limiting structures;
thermal bridges in the limiting structures;
faulty heating systems;
faulty sections of the heated floor systems;
location of heating elements of the heated floor systems;
faulty ventilation systems;
hidden defects, overheated electrical power network and supply elements;
hidden leakages;
roof drenching;
places of formation of a condensate (dew-points), et al.
Application of one Test for tightness is restricted. In particular, by means of it a degree of tightness, as well as location of leak section can be determined, however it is difficult to establish an exact source. The leakage trajectory can pass through the entire building block (crossing all not tight sections). Such type of leak allows for a sufficiently large volume of air to get inside. Movement of air streams depends on the wind strength and direction, the form of a building and especially its roof etc.
When the Test for tightness and infra-red heat vision filming is performed together, you can achieve the maximum reliability of control of air permeability of the building structure. Moreover, heat visors allow to record graphically the air infiltration and ex-filtration sections.