Electric Floor Heating Research Articles

Impact of heat source at radiant electric heating panel

Among panel heating systems (PHS), floor heating (FH) is mostly used in Serbia because it offers special benefits in terms of thermal comfort and final energy consumption. Uniform temperature distribution in the hanging room, low temperature mode, fairly simple way of installation and maintenance, long service life, simple ambient temperature control and currently low price of electricity in Serbia, is the reason for the increasing use of electric heating cables (EHC) in PHS. In addition to a number of advantages, when using floor heating panels (FHP), it must be taken into account that the maximum temperature of the available free floor surface does not exceed the recommended limits because it has a negative impact on thermal comfort in the room and negatively affects the health of users.In this paper, the subject of experimental and numerical research is a low-temperature electric floor heating panel (LTEFHP) in specific conditions. In the experimental part of the paper, a two-storey test house (TH) was used, with dimensions of one floor, ie. thermal zones 1 000 × 800 × 650 mm, within which a pre-prepared physically prepared electric heating panel (EHP) is implemented as an active heating system. In order to test the test houses and the mentioned heating system under stationary conditions, a test chamber (TC) with dimensions 1 500 × 1 500 × 1 800 mm was used, in which the following three scenarios were simulated (when the mean air temperature inside the test chamber: tTC = -5°C, tTC = 0 °C and tTC = 4.5 °C). The same experimental installation (for the same simulation scenarios) was tested numerically in the second part of the paper, first in the EnergyPlus software, and then in the Ansys Workbench software. The main goal of this paper is to use different methods and tools to show the appropriate temperature fields in the characteristic layers of the examined geometric structure.

Simulation Analysis of Heat Transfer on Low Temperature Hot-Water Radiant Floor Heating and Electrical Radiant Floor Heating

Radiant floor heating as a new type of energy-saving heating method has more and more used in modern building heating project. According to the different heat source, radiant floor heating is divided into low temperature hot-water floor radiant heating and electrical floor radiant heating. This paper analyzes the heat transfer process of structure layer of the low temperature hot-water and electrical floor radiant heating system, establishes two dimensional steady heat transfer mathematic model, numerical calculation using Fluent software. Respectively simulated when floor materials is different, the heat transfer process of low temperature hot-water floor radiant heating and electrical floor radiant heating system, The analysis results show that: for low temperature hot-water floor radiant heating, when floor material is soft wood, the ground temperature distribution is more uniform; for electrical floor radiant heating, when floor materials is marble, the ground temperature distribution is more uniform; electrical floor radiant heating is more energy saving, and temperature distribution in the ground of floor using the constant heat flux electric heating mode is more uniform than which using the low temperature hot water heating mode.

Financial viability of energy-efficiency measures in a new detached house design in Finland

This study analyses alternative energy-saving design concepts for a typical new detached house design in Finland. The impact of these design concepts on the construction costs and on the total delivered energy needs of the building were calculated, and the financial viability of the different concepts analysed. Different thermal insulation and airtightness properties of the building envelope and different ventilation’s heat recovery efficiency assumptions were tested in the analysis work. Other variations modelled included the heating mode: direct electrical floor heating, or floor heating via an air or ground source heat pump. Among these alternatives, the estimated annual consumption of purchased energy for running the household varied extensively, in the range 57–182 kW h/net floor m 2. With the real interest rate set at 3%, the payback period was shortest for the air source heat pumps (9 years). When a heat pump was installed in a house with higher energy consumption, the payback period was 7 years, and if it was installed in the ‘ultra low-energy’ house designs, the payback period was over 13 years. Investment to thick thermal insulation of envelope was unattractive in Finland. The results of this study can be generalized to similar climates and techno-economic environments.

Study on the Simulation of Electric Heating Phase Change Floor System

Establishing a kind of electric heating system of phase change floor, analysing the stability and comfort through the simulation. Choosing the phase change materials, which the phase transition temperature is 29°C and the latent heat is 188 kJ/kg. The phase change materials used in electric heating floor heating system, comparing the general electric heating floor system, Calculating the floor surface temperature and indoor air temperature. It turned out that the heat storage of phase change floor system will be well, when compared to the common system, indoor temperature changes gently, human comfort higher. Phase change materials stores the cheap electricalheatenergy, and releases during daytime, So as to realize energy conservation and economy .

Highly reflective coatings for interior and exterior steel cladding and the energy efficiency of buildings

The effect of surface heat-radiation properties of coil-coated steel cladding material on the energy efficiency of buildings in Nordic climate is addressed by parallel temperature and energy usage measurements in a series of test cabins with different exterior solar reflectivity and interior thermal reflectivity. During one year, a number of one- or two-week experiments with air conditioner cooling and electrical floor heating were made while logging air-, radiation- and surface temperatures, energy consumption and weather conditions. Measurements show significant energy savings in the test cabins by the use of high thermal reflectivity interior surfaces both during heating and cooling and a strongly reduced cooling demand by the use of high solar reflectivity exterior surfaces. Results are interpreted within the context of a steady-state energy flux model, to illuminate the importance of surface resistance properties (radiation and convective heat dissipation).

Preparation and application effects of a novel form-stable phase change material as the thermal storage layer of an electric floor heating system

A novel form-stable phase change material (FSPCM) was prepared, which comprises micro-encapsulated paraffin (MEP) as the latent heat storage medium and high density polyethylene/wood flour composite as the matrix. It has the following merits: proper phase transition temperature, large apparent specific heat in phase change temperature region, suitable thermal conductivity, good shape retention and dimensional stability. Therefore, it is suitable for the applications in energy efficient buildings without encapsulation. Simulation studies were performed to investigate the temperature-regulating and cost-reduction effects of the FSPCM as the thermal storage layer (TSL) material of an electric floor heating system (EFHS). The results show that it is promising to use the FSPCM plate as the TSL to achieve better temperature-regulating and cost-reduction effects, and the application effects depend on the heating mode of the EFHS and the thickness of FSPCM plates. The cost-benefit analysis indicates also that the prepared FSPCM has the potential to serve as the TSL in an electric floor heating system.

Experimental studies on the indoor electrical floor heating system with carbon black mortar slabs

A room using carbon black mortar slabs (CBMS) as the electrical floor heating element has been built in our lab. Studies showed that an electrical power of about 123.8 W/m 2 resulted in the indoor temperature rise of 10 °C within 330 min. Temperature distribution along the height of the room was uniform. Temperature rise was slightly higher if floor tiles rather than the wood flooring was used. In the process of heating, self-heating of CBMS has consumed more than 30% of the generated heat by Joule effect, which was advantageous for the stability of the thermal state. The indoor air absorbed over 50% of the generated heat. Results derived from repeated tests show that the electrical power of the CBMS system was stable during several cycles of heating. Further, the procedure and power consumption for the system to maintain a certain indoor temperature were studied. Continuous tests for 72 h has shown that the higher the indoor controlled temperature was, the longer the working time and the shorter the rest time in every cycle of heating were required. Accordingly, the power consumption to maintain the heat state increased with the controlled temperature increasing.

Study of an electrical heating system with ductless air supply and shape-stabilized PCM for thermal storage

A kind of electrical floor heating system with a shape-stabilized phase change material (PCM) which has been studied at Tsinghua University in our previous studies, can provide space heating during the whole day and can be controlled conventionally. However, this is not suitable for office buildings where no space heating is needed at night. The effective control is very important for the heating system in such buildings. In this paper, we studied a kind of new electrical floor heating system with ductless air supply and shape-stabilized PCM for thermal storage in order to overcome the shortcomings of the passive under-floor electric heating system with thermal storage. In this paper, we investigated its thermal performance by experiments and simulation, calculated the effects of various factors and discussed the application feasibility in different climate regions. The results show that the total electrical energy consumption was shifted from the peak period to the off-peak period, which would provide significant economic benefits because of the different day and night electricity tariffs. The system can be designed by choosing PCM with proper melting temperature and be controlled by varying velocity of air supply in different conditions.

Electricity dependency and CO 2 emissions from heating in the Swedish building sector—Current trends in conflict with governmental policy?

Coal-condensing power is marginal production in the deregulated Nordic power market and an increase in electricity consumption will therefore result in increased CO 2 emissions. One goal of the Swedish energy policy is to reduce the amount of electricity used for heating in the building sector. This paper investigates the potential for reduction in electricity dependency and CO 2 emissions from heating, taking the energy infrastructure into account, here defined as the capital stock of the buildings and heating systems together with geographical variations in heat intensity. In order to include the energy infrastructure in the analysis the study is made on a regional level (Southern Sweden) applying a comprehensive database describing the energy infrastructure of the region. The paper compares two scenarios for converting the heating systems of the region: one employing energy savings and with the aim to phase out the oil and most of the electricity used for heating purposes and a second which illustrates the effect if the current trend in the heating market continues. Both scenarios apply commercially available technologies only. From the second scenario it is seen that the current trend—contrary to the aim of the Swedish Governmental policy—shows an increase in electricity dependency for heating, mainly due to a large diffusion of heat pumps, but also due to installations of electrical floor heating and electricity heating systems installed in newly constructed one- and two-dwelling buildings. However, the options proposed in first scenario show that it is possible to reach significant reductions in the electricity dependency due to heating and in corresponding CO 2 emissions. An analysis of the age structure of the heating systems shows that the transformation of the heating system is not completed until the year 2025, if new investments for replacement of heating systems are made only provided they have reached their economical life time, and only applying heating technologies which at present are known to be economically competitive. It can be concluded that future policies on transforming the energy system should be based on an analysis that takes the entire energy infrastructure (in this case of heating system) into account (e.g. not directed towards single technologies). More specifically for the region studied, which is considered representative for Sweden as a whole, policies should aim at installing heat pumps to replace electricity heating only in regions with low heat density where district heating is not competitive, in contrary to the present situation where heat pumps replace all types of heating systems.

電気式床暖房室内の熱放射場に関する実験的研究

Thermal radiation field in a room with electric floor heating was investigated by experiments using a cubic net radiometer. The surface temperature of the floor was set at a high temperature of 50 degree centigrade at the highest, for the sake of conducting an evaluation method of thermal environment in the room with floor heating. The height of measurement was selected at 50cm above the floor corresponding to the posture of a human body sitting on the floor. Using the cubic net radiometer made it possible to analyze the variation of thermal environment in the room owing to the directionality of the instrument.

The Performance of Under-floor Electric Heating System with Latent Thermal Storage

This paper illustrates a structure of electric floor heating system with latent heat thermal storage plate. This system can charge heat by using cheap nighttime electricity and discharge the heat stored at daytime. A theoretical model is developed, which can analyze the thermal performance of buildings applying such system in winter. The thermal performance of the heating system and the effects of various factors on it are analyzed by modeling and simulation. For a given room located in different climate regions, the optimal effect of using such system is predicted, which testifies the feasibility of this heating mode in different climate regions.

Stationary thermal field in a long duct of an electrical heating system

The subject of this work is the analysis of a stationary thermal field in a long duct of an electrical floor heating system. Parallel sectors of the heating cable are modelled by heat sources of the emitted power linear density. The resultant thermal field is described by a partial differential equation of the elliptic type with boundary conditions of the second and third kind. The problem is solved by the method of eigenfunctions. The results are reduced to a dimensionless form and numerically processed. The field distributions obtained are presented in graphical form, with the number of sectors of the heating cable in the duct being changed.

床暖房温度の床座の人体に及ぼす影響に関する研究(電気床暖房装置を使用した場合について)

床暖房温度の床座の人体に及ぼす影響に関する研究(電気床暖房装置を使用した場合について)