Leaving its mark in isolation for a long period, Ispek KFK especially carries out insulation of mechanical installation, heating, cooling and ventilation ducts, sound insulation and water sealing successfully.

Ispek KFK successfully performs isolation of chimney, tank and similar devices and other isolation like mechanical installation materials, hot oil and steam boiler, air conditioning central offices, armature and all installation fields and performs isolation works such as covering them with galvanized, aluminium or rustproof materials.

Insulation in Installations

Leaving its mark in isolation for a long period of time, Ispek KFK especially carries out insulation of mechanical installation, heating, cooling and ventilation ducts, sound insulation and water sealing successfully.

Ispek KFK successfully performs the isolation of chimney, tank, and similar devices, and other isolation like mechanical installation materials, hot oil and steam boiler, air conditioning central offices, armature and all installation fields, and performs the isolation works such as covering them with aluminium or rustproof materials.

Types of Isolation and Used Semi-Insulating Materials

Thermal Isolation;
Polyethylene Pipe: It is polethylene-based material, used in thermal insulation in installations and industrial applications. Providing zero water vapour permeance, it provides heat resistance.

Rubber Polyethelene: It is used as insulation material in air ducts and aeration tanks, large pipes, hot and cold-water circuits and heating and cooling systems in hot and cold-water circuits.

Polyethylene Plate: It is used as thermal insulation material inside and outside of air ducts. It is also successful in thermal, humidity and sound insulation. According to its areas of use, it is used as self-adhesive, foiled and polystyrene- coated.

Air-conditioning Plate: It is used for the external thermal insulation and internal thermal and sound insulation of ventilation and air conditioning ducts.

Sound Insulation:
• Glass wool

• Rock wool

• Nifaf

Impermeability in Air Ducts

Duct Air Leakage

It is important that the amount of air leakage is within required limits in duct system due to matters, stated below:

• Eliminating additional energy cost, which may occur as a result of using bigger devices than required or less efficient devices and avoiding waste of energy

• Avoiding additional labour cost, required to ensure air distribution due to high air leakage levels

• Minimizing sound due to air leakage

• Issues, faced especially in systems, where frequency converters are used Zero leakage is a required feature in distribution systems of poisonous gas but it is not a target in normal applications. Such a target shall require too much labour and time and shall increase cost too much.

Relation between Air Leakage – Space

The amount of leakage in round or rectangular air ducts changes practically in line with the air duct space although it also changes according to variable duct sizes or the frequency of used fittings.

Relation between Air Leakage and Pressure

Air leakage in an orifice of a duct area, considered in a given pressure, shall change according to shape of orifice. Leakage orifices in a mounted duct system shall be in various sizes. Thus there is no possibility to provide a definite value regarding the connection between pressure / air leakage. However according to studies, carried out, air leakage is related with 0.65 power of pressure. This value is accepted by EUROVENT in preparing 2/2 document.

Acceptable Limits in Air Leakage

• In considering permitted limits in air leakage, firstly pressure limits in ducts have to be taken into account.
• By testing all ducts, operating in high pressure, the compliance of air leakage limits have to be detected. Carrying out leakage tests of duct systems with medium and low pressure should not be stated as obligatory in standards. If pressure test is required in medium and low pressure ducts, then this matter has to be stated in specifications of the project. Permissible air leakage is gathered under four pressure standards of impermeability in DW142. Given values for Class A, B, C are the same as the values, stated in Eurovent. DW142 states Class A impermeability standards in low-pressure duct systems, Class B impermeability in medium-pressure duct systems and Class C and Class D impermeability standards in high-pressure duct systems.
• Relation between Air Leakage – Total Air Flow
• As air leakage is dependent on duct surface area, it is not possible to determine air leakage as a percentage over total air amount. At the same time, as a performance standard, a specified air leakage per cent cannot be given as an acceptable value. However many studies, carried out, have showed that in low-pressure air conditioning ducts, air leakage shall be %6 of total air amount, %3 in medium-pressure air conditioning ducts and %2 - %0.5 in high pressure air conditioning channels.

Making Air Leakage Test in Ductwork

A – Leakage Class shall be determined.
CLASS A Up to 500 Pa. Positive pressure CLASS. B Up to 1000 Pa. Positive pressure CLASS
C Up to 2000 Pa. Positive pressure CLASS
D Up to 2500 Pa. Positive pressure

B - Test Pressure shall be determined. Test pressure of each zone that shall be tested shall be determined and test pressure shall fulfil average pressure.
Pm = Average operating pressure,
P1 = Operating pressure at the head of a duct,
P2 = Operating pressure at the end of a duct

C - Test Zones shall be determined. Test device and working conditions at the field have to be taken into account.

D – Duct Area that shall be tested shall be calculated.

E – Permissible Total Amount of Air Leakage shall be calculated.

F - Test Procedure
• f1 Air leakage in ducts are measured with a special device. Sample device here is FLAKT/ABBA model. ABBA consists one fan, with which speed and airflow rate can be adjusted, 2 U-tube manometers, with which static test pressure and airflow rate through the pipe can be read; 100 or 50 mm measuring pipe and flexible pipe.

• f2 All openings ( vent outlets, branch vents etc.) in the test areas are closed to provide impermeability.

• f3 Testing device is connected to air duct properly and the fan is operated and its speed is increased gradually. Here the aim is to pressurize inner part of duct and to reach estimated test pressure value. This value is read from the manometer, mounted on duct and after reaching average static pressure value, the fan has to be operated for 5 minutes before measuring.

• f4 The pressure difference, read in second manometer (connected to pipe between fan and duct), shows the pressure from speed of the air (velocity head ), this shows that although the duct, measured, is closed from all sides, some amount of air leaks outside. Here as the aim is not to achieve zero leakage, the result is acceptable, if the leakage is in the limits of the selected leakage class. With pressure value, taken, and the conversion tables or graphics, provided by producing company, leakage amount in duct section shall be determined. The test has to be carried out for 15 minutes and it has to be observed whether there is any increase in the amount of leakage or not.

• f5 Received results are filled into test report.

Sample Test Report

Smoke Tablets

These are capsules, exhaling smoke intensively. As smoke shall come out from leaks, it is possible to detect and remove leakage. Smoke test is the most reliable and practical testing method.

By listening

Air, coming out of leaks, makes a sound like a whistle, whose volume changes according to the geometry of orifice and duct pressure.

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