# The Ability to Control VOC Emissions from Multilayer Building Materials
## 2 Materials and Methods
### The Electrically Powered Radiant Floor Heating System LRFHS-Selected Laboratory Samples  
LRFHS simulates the floor's real conditions with a radiant floor heating system, taking into account the relationship between the heater's temperature and the temperature of the top surface of the floor. In order to assess the VOC emission characteristics of construction products used, the chamber tests were carried out for dry (leaving room, bedroom simulation) and wet rooms (bathroom simulation). The construction practice (e.g., EN 1264) indicate the permissible temperature of the floor surface layer of the heated floor. The temperature for residential and office spaces should not exceed 29 \({}^{\circ}\)C, and for wet rooms (e.g., bathroom), it should not be higher than 33\({}^{\circ}\)C. On this basis, two types of working conditions were simulated by the authors for the study of VOC emissions from construction products used with the radiant floor heating system: dry (type D) and wet (type W). For D-type rooms, the surface layer's maximum temperature, which was an oak parquet of 29 \({}^{\circ}\)C, was assumed. In the case of W-type rooms, the top layer was ceramic tiles, and their maximum temperature was 33 \({}^{\circ}\)C. It was assumed that the humidity RH for D-type simulation will be 50%, and for W rooms, 80% (in a test chamber). The test results for W and D simulations were compared with the room test conditions without floor heating (23 \({}^{\circ}\)C and 50% or 80% RH). Two types of samples were prepared for the testing of emissions of volatile organic compounds corresponding to the conditions in dry (type D) and wet (type W) simulations. The sample structure was based on the installation scheme of the heating floor layers, shown in Figure 1.  
The floor heating sample was located in a ceramic housing made of 10 mm thick fibre-cement sheets. The properly cut sheets pieces were connected with each other by means of screws so as to form a cuboid open at the top. One wall of the housing wasuns-crewed/opened in order to introduce subsequent layers of the sample. The use of ceramic housing of the sample packaging allowed the authors to obtain thermal inertia which allowed for better thermal stabilisation of the system. It also has slots where high-quality temperature sensors T1, T2 and T3 were inserted between the sample layers. The outer walls of all samples in the ceramic housings were additionally protected with aluminium foil against possible VOC emission from the side walls or joints at the final stage of preparation. The surface area of the base of the ceramic housing and each of the layers was 0.04 m\({}^{2}\). It was set so that a chamber loading factor L--the ratio of the test specimen area to the chamber volume of product--was 0.4 m\({}^{2}\)/m\({}^{3}\), which is the test-recommended value for products used for floors in accordance with the EN 16516 standard [5]. The fixed layers of the sample, permanently built into the ceramic housing of the sample regardless of type D or W (Figure 2), placed on the bottom of the structure, are thermal insulation (floor polystyrene, 30 mm), a ceramic tile (4 mm) and an electric heater as presented in Figure 3 cross-section of the sample types D and W). A concrete block with a thickness of 6 cm, corresponding to the concrete floor screed, was placed on the heater. It was prepared in a special form in accordance with the EN 12390-2 standard. Process thermometers shields were placed at the bottom and top of the mould to insert temperature sensors during the emission tests, and the concrete blocks were seasoned for 28 days after formation. The basic element of the emitting sample was a multilayer of under-floor construction products, different for samples of type W and D. For