Partner: Jan Kośny, PhD |
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Doctoral thesis
1991 | Teoretyczna i doświadczalna analiza efektywności przegród kolektorowo-akumulacyjnych
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Recent publications
1. | Kośny J.♦, William Anthony M.♦, Yarbrough D.♦, Kossecka E. Ł., Kaushik B.♦, Application of Phase Change Materials and Conventional Thermal Mass for Control of Roof-Generated Cooling Loads, Applied Sciences, ISSN: 2076-3417, DOI: 10.3390/app10196875, Vol.10(19), No.6875, pp.1-28, 2020 Abstract: Among all of the internal fabric and external enclosure components of buildings, sloped roofs and adjacent attics are often the most dynamic areas. Roofs are exposed to high temperature fluctuations and intense solar radiation that are subject to seasonal changes in climatic conditions. Following the currently rising interests in demand-side management, building energy dynamics, and the thermal response characteristics of building components, this paper contains unpublished results from past studies that focused on innovative roof and attic configurations. The authors share unique design strategies that yield significant reduction of daytime roof peak temperatures, thermal-load shavings, and up to a ten-hour shift of the peak load period. Furthermore, advance configurations of the roofs and attics that are discussed in this paper enable over 90% reductions in roof-generated peak-hour cooling loads and sometimes close to 50% reductions in overall roof-generated cooling loads as compared with traditionally constructed roofs with the same or similar levels of thermal insulation. It is expected that the proposed new roof design schemes could support the effective management of dynamic energy demand in future buildings. Keywords:roofs and attics, thermal performance, numerical analysis, field testing, dynamic thermal response, peak load management, thermal storage, phase change materials Affiliations:
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2. | Kośny J.♦, Fallahi A.♦, Shukla N.♦, Kossecka E., Ahbari R.♦, Thermal load mitigation and passive cooling in residential attics containing PCM-enhanced insulations, SOLAR ENERGY, ISSN: 0038-092X, DOI: 10.1016/j.solener.2014.05.007, Vol.108, pp.164-177, 2014 Abstract: Residential attics has the potential to be one of the most energy efficient building components by combining thermal processes of attic floor insulation, attic air space, ventilation in attics, and solar collecting roof decks. Large amounts of solar energy collected by the roofs in cooling-dominated and mixed climates generate excess cooling loads, which need to be removed from the building by the space conditioning systems. This paper investigates potential ways to improve the thermal design of the residential home attics to minimize the cooling energy consumption in the cooling-dominated and mixed climates. Dynamic thermal characteristics of thick attic floor insulations and blends of phase change materials (PCMs) with insulations are analyzed. Both approaches can provide notable reductions of thermal loads at the attic level. In addition, a significant time shift of peak-hour loads can move a major operation time for air conditioning system from the daytime peak hours to nighttime low demand hours. A reverse heat flow direction can be observed during the day in the case of really thick layers of bulk insulation or PCM-enhanced insulations, compared to the rest of the building envelope components. This effect may provide free passive cooling to the building, and can be very useful in locations of double electrical tariffs with high daytime peak-hour electric energy rates and less-expensive off-peak energy cost. In both of the above cases, an addition of PCM to the bulk insulation brings substantial performance enhancement not available for traditional insulation applications. This paper presents a short overview of dynamic material characteristics and energy performance data necessary for future dynamic applications of different configurations of the attic floor insulation and PCM-insulation blends in residential homes. A series of whole-building scale and material scale numerical simulations were performed on a single story ranch house to analyze potential energy savings and optimize location of PCM within the attic insulation. Keywords:Building envelopes, Attics, Thermal mass, Insulation Affiliations:
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3. | Kośny J.♦, Kossecka E., Brzeziński A.♦, Tleoubaev A.♦, Yarbrough D.♦, Dynamic thermal performance analysis of fiber insulations containing bio-based phase change materials (PCMs), ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/j.enbuild.2012.05.021, Vol.52, pp.122-131, 2012 Abstract: Experimental and theoretical analyses have been performed to determine dynamic thermal characteristics of fiber insulations containing microencapsulated phase change material (PCM). It was followed by a series of transient computer simulations to investigate the performance of a wood-framed wall assembly with PCM-enhanced fiber insulation in different climatic conditions. A novel lab-scale testing procedure with use of the heat flow meter apparatus (HFMA) was introduced in 2009 for the analysis of dynamic thermal characteristics of PCM-enhanced materials. Today, test data on these characteristics is necessary for whole-building simulations, energy analysis, and energy code work. The transient characteristics of PCM-enhanced products depend on the PCM content and a quality of the PCM carrier. In the past, the only existing readily-available method of thermal evaluation of PCMs utilized the differential scanning calorimeter (DSC) methodology. Unfortunately, this method required small and relatively uniform test specimens. This requirement is unrealistic in the case of many PCM-enhanced building envelope products. Small specimens are not representative of PCM-based blends, since these materials are not homogeneous. In this paper, dynamic thermal properties of materials, in which phase change processes occur, are analyzed based on a recently-upgraded dynamic experimental procedure: using the conventional HFMA. In order to theoretically analyze performance of these materials, an integral formula for the total heat flow in finite time interval, across the surface of a wall containing the phase change material, was derived. In numerical analysis of the southern-oriented wall the Typical Meteorological Year (TMY) weather data was used for the summer hot period between June 30th and July 3rd. In these simulations the following three climatic locations were used: Warsaw, Poland, Marseille, France, and Cairo, Egypt. It was found that for internal temperature of 24 °C, peak-hour heat gains were reduced by 23–37% for Marseille and 21–25% for Cairo; similar effects were observed for Warsaw. Affiliations:
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4. | Kossecka E., Kośny J.♦, Dynamic thermal performance of the frame wall with PCM-enhanced thermal insulation, ZESZYTY NAUKOWE POLITECHNIKI RZESZOWSKIEJ, SERIA: BUDOWNICTWO I INŻYNIERIA ŚRODOWISKA, ISSN: 0209-2646, Vol.57, No.4, pp.309-316, 2010 | ||||||||||||||||
5. | Kossecka E., Kośny J.♦, Dynamiczna metoda pomiaru zawartości materiału fazowo-zmiennego w izolacji włóknistej, FIZYKA BUDOWLI W TEORII I PRAKTYCE, ISSN: 1734-4891, Vol.4, pp.109-112, 2009 | ||||||||||||||||
6. | Kossecka E., Kośny J.♦, Hot box testing of building envelope assemblies, a simplified procedure for estimation of minimum time of the test, JOURNAL OF TESTING AND EVALUATION, ISSN: 0090-3973, DOI: 10.1520/JTE100795, Vol.36, No.3, pp.242-249, 2008 | ||||||||||||||||
7. | Kossecka E., Kośny J.♦, Three-dimensional conduction z-transfer function coefficients determined from the response factors, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/j.enbuild.2004.06.026, Vol.37, No.4, pp.301-310, 2005 Abstract: A method of derivation of the conduction z-transfer function coefficients from response factors, for three-dimensional wall assemblies, is described. Results of the conduction z-transfer function coefficients calculations are presented for clear walls and separated details which are listed in ASHRAE research project 1145-TRP: ‘‘Modeling Two- and Three-Dimensional Heat Transfer Through Composite Wall and Roof Assemblies in Hourly Energy Simulation Programs’’. Resistances, three-dimensional response factors and so-called structure factors, have been computed using the finite-difference computer code HEATING 7.2. The z-transfer function coefficients were then derived from a set of linear equations, constituting relationships with the response factors, which were solved using the minimum-error procedure. Test simulations show perfect compatibility of the heat flux calculated using three-dimensional response factors and three-dimensional ztransfer function coefficients, derived from the response factors. Keywords:Heat transfer, Thermal response, z-transfer function, Simulation, Building envelope Affiliations:
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8. | Kossecka E., Kośny J.♦, Correlations between time constants and structure factors of building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.I, No.1, pp.175-188, 2004 Abstract: Two methods are proposed of the wall specimen time constant estimation, for the hot box apparatus testing. Directions of the American standard ASTM C 1363-97 are discussed. First method assumes numerical calculation of the response factors and deriving time constant from their ratios. The second one makes use of the approximate relation between the time constant and the product of resistance, capacity and the structure factor. Correlations between time constants and structure factors are examined. Affiliations:
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9. | Kossecka E., Kośny J.♦, Z-transfer function coefficients for simulation of three-dimensional heat transfer in building walls, ARCHIVES OF CIVIL ENGINEERING, ISSN: 1230-2945, Vol.XLIX, No.4, pp.545-558, 2003 Abstract: A method of derivation of the conduction z-transfer function coefficients from response factors, for three-dimensional wall assemblies, is described.Results of the conduction z-transfer function coefficients calculations are presented for clear walls and separated details which are listed in ASHRAE research project 1145-TRP: “Modeling Two- and Three-Dimensional Heat Transfer Through Composite Wall and Roof Assemblies in Hourly Energy Simulation Programs”. Resistances, three-dimensional response factors and so-called structure factors, have been computed using the finite-difference computer code HEATING 7.2. The z-transfer function coefficients were then derived from a set of linear equations, constituting relationships with the response factors, which were solved using the minimum-error procedure.Test simulations show perfect compatibility of the heat flux calculated using three-dimensional response factors and three-dimensional z-transfer function coefficients, derived from the response factors. Affiliations:
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10. | Kossecka E., Kośny J.♦, Influence of insulation configuration on heating and cooling loads in a continuously used building, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/S0378-7788(01)00121-9, Vol.34, pp.321-331, 2002 Abstract: This paper is focused on the energy performance of buildings containing massive exterior building envelope components. The effect of mass and insulation location on heating and cooling loads is analyzed for six characteristic wall configurations. Correlations between structural and dynamic thermal characteristics of walls are discussed. A simple one-room model of a building exposed to periodic temperature changes is analyzed to illustrate the effect of material configuration on the ability of a wall to dampen interior temperature swings. Whole-building dynamic modeling using DOE-2.1E is employed for the energy analysis of a one-story residential building with various exterior wall configurations for six different US climates. The best thermal performance is obtained when massive material layers are located at the inner side and directly exposed to the interior space. # 2002 Elsevier Science B.V. All rights reserved. Keywords:Building heat transfer, Structure factors, Frequency response, Thermal stability, Dynamic thermal performance Affiliations:
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11. | Kośny J.♦, Kossecka E.♦, Multi-dimensional heat transfer through complex building envelope assemblies in hourly energy simulation programs, ENERGY AND BUILDINGS, ISSN: 0378-7788, DOI: 10.1016/S0378-7788(01)00122-0, Vol.34, pp.445-454, 2002 Abstract: In most whole building thermal modeling computer programs like DOE-2, BLAST, or ENERGY PLUS simplified, one-dimensional, parallel path, descriptions of building envelope are used. For several structural and material configurations of building envelope components containing high thermal mass and/or two- and three-dimensional thermal bridges, one-dimensional analysis may generate serious errors in building loads estimation. The method of coupling three-dimensional heat transfer modeling and dynamic hot-box tests for complex wall systems with the whole building thermal simulations is presented in this paper. This procedure can increase the accuracy of the whole building thermal modeling. Thermal modeling, Thermal bridges, Hourly energy simulation programs Affiliations:
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List of chapters in recent monographs
1. 724 | Kośny J.♦, Kossecka E., Yarbrough D.W.♦, Thermal Insulation and Radiation Control Technologies for Buildings, rozdział: Dynamic Thermal Performance of Insulation Combined in Different Formations with Thermally Massive Components, Springer, pp.421-441, 2022 | |
2. 12 | Kośny J.♦, Kossecka E., Yarbrough D.♦, Thermal Conductivity 30 / Thermal Expansion 80 Joint Conferences, rozdział: Use of a Heat Flow Meter to Determine Active PCM Content in an Insulation, DEStech Publications, Inc., Daniela S. Gaal, Peter S. Gaal (Eds.), pp.642-650, 2010 |
Conference papers
1. | Urban B.♦, Engelmann P.♦, Kossecka E., Kosny J.♦, Arranging Insulation for Better Thermal Resistance in Concrete and Masonry Wall Systems, 9th Nordic Symposium on Building Physics – NBS 2011, 2011-05-29/06-02, Tampere (FI), No.3, pp.1-9, 2011 Abstract: This paper investigates how the spatial arrangement of thermal insulation influences the overall thermal resistance of concrete and masonry wall systems. Multi-dimensional finite difference modeling was used for this purpose. Concrete masonry units (CMUs) are commercially produced in various geometries and with different weight concretes. Although insulation inserts can increase a CMUs thermal performance, thermal bridging through the solid webbing of the CMUs can greatly reduce the effectiveness of the integrated insulation. Different commercially available CMU geometries and concrete weights were investigated using finite difference modeling to show the impact on overall CMU R-value and to determine the thermal efficiency of the insulation inserts. Keywords:thermal insulation, building envelope, masonry, concrete, thermal performance Affiliations:
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2. | Kossecka E., Kośny J.♦, Thermal balance of a wall with PCM-enhanced thermal insulation, CESBP 2010, 1st Central European Symposium on Building Physics, 2010-09-13/09-15, Kraków (PL), pp.265-271, 2010 Abstract: PCM–insulation mixtures functionas light weight thermal mass components.It is expected that these types of dynamic insulation systems will contribute to the objective of reducing energy use in buildings. In this paper, dynamic thermal properties of a material in which phase change occurs are analyzed, using the temperature-dependent specific heat model. Integral formula for the total heat flow in finite time interval, across the surface of a slab of the phase change material was derived. Simulations have been performed to analyze heat transfer through a light-weight wall assembly with PCM-enhanced insulation, in different external climate thermal conditions. Results of simulations indicate that for cyclic processes, the effect of PCM in an insulation layer results in time shifting of the heat flux maxima and not in reduction of the total heat flow. The heat gains maxima, resulting in high cooling loads, are shifted in time by about two hours and reduced upto 22% for not very high external sol-air temperatures. Affiliations:
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3. | Kośny J.♦, Yarbrough D.♦, Miller W.♦, Shrestha S.♦, Kossecka E., Lee E.♦, Numerical and Experimental Analysis of Building Envelopes Containing Blown Fiberglass Insulation Thermally Enhanced with Phase Change Material (PCM), CESBP 2010, 1st Central European Symposium on Building Physics, 2010-09-13/09-15, Kraków (PL), pp.272-278, 2010 Abstract: Different types of Phase Change Materials (PCMs) have been tested as dynamic components in buildings for at least 4 decades. Most of historical studies have found that PCMs enhance building energy performance. The PCMs store energy and alter the temperature gradient through the insulated cavity because they remain at a nearly constant temperature during the melting and solidifying stages. The use of organic PCMs to enhance the performance of thermal insulation in the building envelope was studied at the Oak Ridge National Laboratory during 2000 – 2009. PCMs reduce heat flow across an insulated region by absorbing and desorbing heat (charging and discharging) in response to ambient temperature cycles. The amount of heat that can be stored in PCMs is directly related to the heat of fusion of the material, which is between 116 J/g to 163 J/g (or 50 to 70 Btu/lb) for the most - popular micro encapsulated paraffinic PCMs, or fatty acid materials used in this research. This paper presents experimental and numerical results from the long-term thermal performance study focused on blown fiber glass insulation modified with a novel spray-applied micro encapsulated PCM. Experimental results are reported for both laboratory - scale and full - size building elements tested in the field. Test work was followed by detailed whole building Energy Plus simulations in order to generate energy performance data for different US climates. Affiliations:
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Conference abstracts
1. | Kosny J.♦, Curcija Ch.♦, Fontanini A.♦, Kossecka E., A New Approach for Analysis of Complex Building Envelopes in Whole Building Energy Simulations, Buildings XIII - Thermal Performance of the Exterior Envelope of Whole Buildings Conference, 2016-09-04/09-08, Clearwater Beach, FL (US), pp.1-26, 2016 Abstract: The ability for reduction of whole-building energy consumption depends, in large scales, from correct predictions of building thermal loads with the building’s envelope characteristics being one of the most important factors. Since most of today’s building envelopes are complex three-dimensional networks of structural, insulation, and finish materials, the potential for correct predictions of their thermal performance depends on availability of acceptable, scientifically valid, consensus procedures for accurately implementing a building’s envelope thermal characteristics into whole-building energy simulation programs.
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