scholarly journals Transient simulation study of floor heating systems

2019 ◽  
Vol 10 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Lucie Horka ◽  
Jiri Hirs
Keyword(s):  
Surrogate Model ◽  
Heating System ◽  
Thermal Capacity ◽  
Heat Fluxes ◽  
Heating Power ◽  
Transient Simulation ◽  
Insulation Material ◽  
Heating Systems ◽  
Computational Performance ◽  
Floor Heating

This case study is aimed at transient simulation of floor heating systems. There is comparison of surface floor temperatures and heat fluxes changes of different systems over time. The first studied system is a dry floor heating system which consists of system boards made from insulation material, spreader plates, and it is covered by cement fiber boards. The second examined system is heavy wet concrete floor heating system whose heating power is set identically as heating power of dry floor heating system. Mean temperature of heating water is investigated. All simulations, both time steady-state and transient, are performed in software CalA. Reduction of duration and computational performance of simulation is achieved by creation of a surrogate model. The surrogate model evinces identical surface temperatures and heat fluxes. Total number of computational grid is reduced and therefore lower number of equations is solved. Results show that dry floor heating system has faster response than concreate floor heating system. It is caused by lower weight and lower thermal capacity of this system.

scholarly journals Control of Heat Pumps with CO2 Emission Intensity Forecasts

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2851 ◽  
Author(s):  
Kenneth Leerbeck ◽  
Peder Bacher ◽  
Rune Grønborg Junker ◽  
Anna Tveit ◽  
Olivier Corradi ◽  
...  
Keyword(s):  
Process Model ◽  
Electrical Power ◽  
Heating System ◽  
Heat Pumps ◽  
Thermal Capacity ◽  
Building Codes ◽  
Thermal Mass ◽  
Thermostatic Control ◽  
Co2 Emission Intensity ◽  
Floor Heating

An optimized heat pump control for building heating was developed for minimizing CO 2 emissions from related electrical power generation. The control is using weather and CO 2 emission forecasts as inputs to a Model Predictive Control (MPC)—a multivariate control algorithm using a dynamic process model, constraints and a cost function to be minimized. In a simulation study, the control was applied using weather and power grid conditions during a full-year period in 2017–2018 for the power bidding zone DK2 (East, Denmark). Two scenarios were studied; one with a family house and one with an office building. The buildings were dimensioned based on standards and building codes/regulations. The main results are measured as the CO 2 emission savings relative to a classical thermostatic control. Note that this only measures the gain achieved using the MPC control, that is, the energy flexibility, not the absolute savings. The results show that around 16% of savings could have been achieved during the period in well-insulated new buildings with floor heating. Further, a sensitivity analysis was carried out to evaluate the effect of various building properties, for example, level of insulation and thermal capacity. Danish building codes from 1977 and forward were used as benchmarks for insulation levels. It was shown that both insulation and thermal mass influence the achievable flexibility savings, especially for floor heating. Buildings that comply with building codes later than 1979 could provide flexibility emission savings of around 10%, while buildings that comply with earlier codes provided savings in the range of 0–5% depending on the heating system and thermal mass.

scholarly journals METHODOLOGY OF THE PRIMARY DATA RECONSTRUCTION OF SINGLE PIPE HEATING SYSTEMS/VIENVAMZDŽIŲ ŠILDYMO SISTEMŲ PIRMINIŲ DUOMENŲ NUSTATYMO METODIKA

1999 ◽  
Vol 5 (5) ◽  
pp. 318-322
Author(s):  
Edvardas Tuomas ◽  
Saulius Neverbickas
Keyword(s):  
World War Ii ◽  
District Heating ◽  
Heating System ◽  
Heat Fluxes ◽  
Primary Data ◽  
Complex Coefficient ◽  
Heating Systems ◽  
Pipe System ◽  
Central Heating ◽  
Single Pipe

The majority of dwellings in Lithuania are situated in blocks of flats. The dwellings were built after World War II and they are heated by single pipe central heating systems, connected to district heating. The dwellers are not quite satisfied with such a heating system and try to improve it, but do that in a wrong way, by increasing the surface of radiators. Such means lead to violation of thermal regime and comfort conditions for other dwellers. There exists sometimes the necessity of reconstructing premises and together—the heating system. During the reconstruction the primary heat fluxes from radiators should be known, but very often such data are lost and only the size of radiators (number of sections) are known. To reconstruct the required primary data for single pipe systems is complicated because the temperatures of inlet and outlet water for radiators are unknown. In this article the methodology is proposed how to perform the calculations leading to the required data. The aim of calculations is the establishment of heat fluxes from each radiator connected to the riser. Heat flux from radiator can be calculated according the formula (1) but the complex coefficient is unknown. It could be found from formulae (2) but some magnitudes are unknown. According to the proposed methodology the values of unknown magnitudes are taken approximately and calculations are performed with iterations. In such a way the flow rate of water in riser is established from formula (3), which is the same for each radiator (the property of single pipe system). From formulas (3) and (4) an equation is produced (5), and is used for calculations of unknown temperatures. The equation (6) is used for calculation of heat fluxes from radiators. To carry out the above-mentioned calculations without computer practically is impossible due to many cycles of iteration. The programme was prepared to make easy all these calculations. The scheme of algorithm of programme is given in Fig 1. An example of calculation is given in this article. Calculations were fulfilled by newly created programme. The riser chosen for calculation is shown in Fig 2. The results of calculation are given in Table 1. The table shows that according to the proposed methodology the programme based on it can be used for reconstruction of primary data of single pipe heating systems successfully.

scholarly journals Heat Supply Comparison in a Single-Family House with Radiator and Floor Heating Systems

Buildings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Amir Vadiee ◽  
Ambrose Dodoo ◽  
Elaheh Jalilzadehazhari
Keyword(s):  
Heat Supply ◽  
Heating System ◽  
Heat Losses ◽  
Cold Climate ◽  
Single Family ◽  
Heating Systems ◽  
Family House ◽  
Flooring Material ◽  
Floor Heating

Floor heating and radiators are two of the most common types of hydronic heating systems used for space heating in single-family houses in cold climate regions. Notwithstanding, there are few comparative studies on indoor temperature distribution and system cost evaluations for radiators and floor heating. Furthermore, there are no aligned outcomes in terms of total heat supply for a single-family house with radiators or floor heating. In this study, the effect of building energy efficiency level and construction type, including flooring material, on the supply heating demand and transmission heat losses were studied for both radiator and floor heating systems. For this purpose, a single-family house located in Växjö, Sweden, was modeled as a case study. The heating demand was supplied with a district heating system with a similar supply temperature at 45 °C for both the radiator and floor heating system. A sensitivity analysis was also performed to assess the effect of flooring configurations on the annual supply heating demand for both conventional and passive versions of the case-study building. The results showed that the radiator-integrated building had a lower supply heating demand in comparison with the floor heating-integrated buildings. Based on the sensitivity studies, the flooring material did not have a significant influence on the supply heating demand and on the transmission heat losses in the case of the radiators. The supply heating demand was only reduced up to 3% if the flooring U-value was improved by 60%. The results also showed that refurbishment in a standard conventional building with a radiator heating system based on the passive criteria led to a 58% annual energy savings, while this amount for a building with a floor heating system was approximately 49%.

scholarly journals Mock-up Test of Time Lag in Floor Heating Systems with PCM

2019 ◽  
Vol 111 ◽  
pp. 06061
Author(s):  
Sung Ho Choi ◽  
Tae Won Kim ◽  
Jin Chul Park
Keyword(s):  
Surface Temperature ◽  
Time Lag ◽  
Heating System ◽  
Time Lags ◽  
Heating Systems ◽  
Floor Surface ◽  
Time Required ◽  
Floor System ◽  
Change Material ◽  
Floor Heating

This research analyzes the time lag, which is a thermal storage performance parameter, when a phase change material is applied to the floor heating system of a mock-up laboratory. The following results are obtained. In terms of the time required for the floor surface temperature to reach 30 °C, the time lag of Room 2 (i.e., the room with the PCM-based floor system) was observed to be 15 min. Additionally, in terms of the time required for the floor surface temperature to decrease to 22 °C, Room 2 exhibited a time lag of 5 h 2 min. Therefore, the study concluded that longer time lags are observed with floor heating systems with PCM.

Experimental Study on Radiant Floor Heating System

2015 ◽  
Author(s):  
C. C. Ngo ◽  
B. A. Alhabeeb ◽  
M. Balestrieri
Keyword(s):  
Heating System ◽  
Conventional Heating ◽  
Design Parameters ◽  
Piping System ◽  
Burial Depth ◽  
Heating Systems ◽  
Radiant Floor Heating System ◽  
Radiant Floor Heating ◽  
Floor Heating ◽  
Floor Temperature

Radiant floor heating systems have become popular due to their advantages over conventional heating systems in residential, commercial and industrial spaces. They are also used for snow and ice melting and turf conditioning applications. This paper presents a general study focuses on the design of radiant floor heating systems and investigates the effect of design parameters such as pipe spacing (ranging from 4 in. to 12 in.), pipe depth (ranging from 2.5 in. to 6.5 in.) and pipe temperature (45 °C, 65 °C and 85 °C) on the performance of radiant floor heating system embedded in different mediums (air, gravel and sand). The experimental results showed that a radiant heating system with pipes embedded at a shallow burial depth and placed closer together resulted with a more desired floor temperature distribution. The average floor temperature was also higher when the piping system was embedded in an air-filled space instead of a porous medium such as gravel or sand.

Modeling of Electromagnetic Heating Systems

2011 ◽  
Vol 383-390 ◽  
pp. 2231-2236
Author(s):  
Wei Jing Gao ◽  
Li Zheng Li ◽  
Wei Shao Peng
Keyword(s):  
Maxwell Equations ◽  
Heating System ◽  
Heating Power ◽  
Heat Power ◽  
Heating Systems ◽  
First Order ◽  
Intermediate Variable ◽  
Electromagnetic Heating ◽  
The Stability ◽  
Stability And Accuracy

Starting with the Maxwell equations, this article introduces the heating power as intermediate variable to modeling of electromagnetic heating system, and gets a non-linear model. Concludes that the ralationship between the heat power and the input current is nonlinear, the temperature and the heating power is the first order linear relationship. The model has importance significances for improving the stability and accuracy of the electromanetic heating system .

scholarly journals Selection of floor heating by MCDA method

2020 ◽  
Vol 18 (3) ◽  
pp. 041-050
Author(s):  
Jacek Karpiesiuk
Keyword(s):  
Mathematical Analysis ◽  
Evaluation Criteria ◽  
Aluminum Foil ◽  
Heating System ◽  
Multiple Criteria Decision Analysis ◽  
Heating Systems ◽  
Construction Market ◽  
Detached House ◽  
Floor Heating ◽  
Selection Of

Using Multiple-criteria Decision Analysis (MCDA), the most favorable floor heating system of a detached house has been selected. The analysis also includes an assessment of the performance of this type of heating on small surfaces (up to 20m2). The choice was made among eight heating variants, adopting various systems available on the construction market powered by water or electricity, including traditional with "wet" screeds, "dry" screeds and lightweight floor heating systems without Screeds. From the set of 14 evaluation criteria, the eight most important ones were identified. Using the summed corrected indicator of mathematical analysis, it was assessed that the best variant is a lightweight floor water heating system on a reactive adhesive without screeds with aluminum foil.

Flow Simulation of Radiant Floor Heating System Using Hele-Shaw Analogy

2014 ◽  
Author(s):  
C. C. Ngo ◽  
C. G. Peinder
Keyword(s):  
Porous Medium ◽  
Flow Simulation ◽  
Green Building ◽  
Heating System ◽  
Heating Systems ◽  
Pipe System ◽  
Set Up ◽  
Radiant Floor Heating System ◽  
Radiant Floor Heating ◽  
Floor Heating

Radiant floor heating systems are becoming increasingly popular in green building designs. Typically, solar or geothermal energy is employed as a source for such hydronic heating systems. Buried heating pipe system can be used for heating both residential and industrial spaces as well as defrosting snow on walkways, driveways and sport fields. Most of the heating pipes considered in such applications are buried in a porous medium (i.e., insulation layer or soils). Hele-Shaw cells with different pipe spacing were constructed to simulate different floor heating configurations. The objective of the present experimental study is to examine the flow field within porous medium using the Hele-Shaw analogy. The flow visualization experiment was set up to investigate how a change in pipe spacing and pipe temperature would affect the flow patterns from the heated pipes. Using time-elapsed photographs, one observes that the flow fields for different pipe spacings with different buoyancy strengths display distinct characteristics.

scholarly journals Effect of Zero Air Change Rate On Particle Dispersion in A Room with Floor Heating

2019 ◽  
Vol 111 ◽  
pp. 02037
Author(s):  
Mustafa Mutlu
Keyword(s):  
Particle Diameter ◽  
Heating System ◽  
Ambient Air ◽  
Particle Dispersion ◽  
Lagrangian Model ◽  
Residential Areas ◽  
Change Rate ◽  
Heating Systems ◽  
Air Change Rate ◽  
Floor Heating

Dispersion of airborne particles in the office and residential areas should be well known as these particles in an enclosed volume has a significant effect on human health. In this study, the effect of the floor heating system, which is often preferred by end users due to the energy efficiency of low heating systems, on particle distribution in a room was investigated numerically. It is essential to examine the floor heating having a significant place among low heating systems, concerning particle dispersion. In enclose volumes, ambient air should be replaced with fresh air that is supplied from outdoor in order to ensure indoor air quality. However, the ideal air change rates may not be met for daily use, even in some cases air change rates might be zero. Therefore, in this study absence of air change were assumed, and after temperature and velocity distributions were determined, five different sized particles were tracked by using Eulerian-Lagrangian model. Additionally, three heating capacities (35 W/m2 41.25 W/m2 and 47 W/m2) of the floor heating system were investigated. In this study, where computational fluid dynamics were used, the effect of drag, lift, thermophoretic and Brownian forces were considered. It was found that particles were settled on walls and ceiling due to zero air change rate, and particle concentration rises in the lower part of the wall as particle diameter increases.

Simulation Study of Dry Floor Heating Systems

2019 ◽  
Vol 887 ◽  
pp. 196-203
Author(s):  
Lucie Horká ◽  
Jiri Hirs
Keyword(s):  
Heat Flux ◽  
Heating System ◽  
Heat Losses ◽  
Insulation Material ◽  
Heating Pipes ◽  
Minimal Thickness ◽  
State Boundary ◽  
Useful Heat ◽  
Floor Heating

This case study is aimed at simulation of dry floor heating system. Heating pipes are inserted in system boards made of thermal insulation. These boards should be supplemented with spreader plates which are installed under the heating pipes. Impact of different thermal conductivity of spreader plates on useful heat flux and uniformity of temperature field is examined. Heat losses are also investigated. These simulations are performed using software CalA with time steady-state boundary conditions. The results show that the dry floor heating system without spreader plates has very low useful heat flux caused by positioning of heating pipes in the insulation material. On the other hand, use of spreader plates causes significant increase of useful heat flux of this system. The higher heat conductivity of spreader plates is, the higher useful heat flux is. The floor surface temperature is also more uniform and the thermal comfort is better. The minimal thickness of additional heat insulation is determined in order that heat losses are lower than ten percent of total heat flux.

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