Can qualitative methods support the development of more flexible and energy saving thermal comfort?

This paper uses examples from a Swedish study to suggest some ways in which cultural variation could be included in studies of thermal comfort. It is shown how only a slight shift of focus and methodological approach could help us discover aspects of human life that add to previous knowledge within comfort research of how human beings perceive and handle warmth and cold. It is concluded that it is not enough for buildings, heating systems and thermal control devices to be energy-efficient in a mere technical sense. If these are to help to decrease, rather than to increase, energy consumption, they have to support those parts of already existing habits and modes of thought that have the potential for low energy use. This is one reason why culture-specific features and emotional cores need to be investigated and deployed into the study and development of thermal comfort.

In Bio-Fuel We Trust

In bio-fuel we trust. Or do we? In this chapter, ethnographic material from Sweden is used to discuss ways sin which trust may influence the choice of bio-fuel for heating purposes. The meaning and substance of trust or distrust, as well as the very conditions for trust, are elaborated on in relation to solar and bio-pellet systems, district heating with bio-fuel, and traditional fireplaces. An important conclusion of this chapter is that the degree to which people perceive others as being like themselves or not tends to be decisive for whether these others are to be trusted, and therefore worth listening to. The context and situation in which a certain heating system is being chosen does not only involve trust in individuals, however, but in companies and the authorities, as well as in the arterfacts themselves. An example is given on how distrust of district heating companies led house owners to reject an offer of district heating despite the comfort and environmental benefit this could have provided. it is shown how this distrust might be resolved by making the rhythm of households and sitrict heating companies more in step with one another. The strong emotional attachment to and deep-felt trust in the traditional fireplace is also analysed, and a question is put forward as to whether these feelings could be transferred to modern bio-pellet stoves. Finally, our great and assured trust in bio-fuel as a main solution to global climate change is shortly commented upon and partly questioned.

TCA Evaluation : Lab Measurements, Modelling and System Simulations

The study reported here is part of a large project for evaluation of the Thermo-Chemical Accumulator (TCA), a technology under development by the Swedish company ClimateWell AB. The studies concentrate on the use of the technology for comfort cooling. This report concentrates on measurements in the laboratory, modelling and system simulation. The TCA is a three-phase absorption heat pump that stores energy in the form of crystallised salt, in this case Lithium Chloride (LiCl) with water being the other substance. The process requires vacuum conditions as with standard absorption chillers using LiBr/water. Measurements were carried out in the laboratories at the Solar Energy Research Center SERC, at Högskolan Dalarna as well as at ClimateWell AB. The measurements at SERC were performed on a prototype version 7:1 and showed that this prototype had several problems resulting in poor and unreliable performance. The main results were that: there was significant corrosion leading to non-condensable gases that in turn caused very poor performance; unwanted crystallisation caused blockages as well as inconsistent behaviour; poor wetting of the heat exchangers resulted in relatively high temperature drops there. A measured thermal COP for cooling of 0.46 was found, which is significantly lower than the theoretical value. These findings resulted in a thorough redesign for the new prototype, called ClimateWell 10 (CW10), which was tested briefly by the authors at ClimateWell. The data collected here was not large, but enough to show that the machine worked consistently with no noticeable vacuum problems. It was also sufficient for identifying the main parameters in a simulation model developed for the TRNSYS simulation environment, but not enough to verify the model properly. This model was shown to be able to simulate the dynamic as well as static performance of the CW10, and was then used in a series of system simulations. A single system model was developed as the basis of the system simulations, consisting of a CW10 machine, 30 m2 flat plate solar collectors with backup boiler and an office with a design cooling load in Stockholm of 50 W/m2, resulting in a 7.5 kW design load for the 150 m2 floor area. Two base cases were defined based on this: one for Stockholm using a dry cooler with design cooling rate of 30 kW; one for Madrid with a cooling tower with design cooling rate of 34 kW. A number of parametric studies were performed based on these two base cases. These showed that the temperature lift is a limiting factor for cooling for higher ambient temperatures and for charging with fixed temperature source such as district heating. The simulated evacuated tube collector performs only marginally better than a good flat plate collector if considering the gross area, the margin being greater for larger solar fractions. For 30 m2 collector a solar faction of 49% and 67% were achieved for the Stockholm and Madrid base cases respectively. The average annual efficiency of the collector in Stockholm (12%) was much lower than that in Madrid (19%). The thermal COP was simulated to be approximately 0.70, but has not been possible to verify with measured data. The annual electrical COP was shown to be very dependent on the cooling load as a large proportion of electrical use is for components that are permanently on. For the cooling loads studied, the annual electrical COP ranged from 2.2 for a 2000 kWh cooling load to 18.0 for a 21000 kWh cooling load. There is however a potential to reduce the electricity consumption in the machine, which would improve these figures significantly. It was shown that a cooling tower is necessary for the Madrid climate, whereas a dry cooler is sufficient for Stockholm although a cooling tower does improve performance. The simulation study was very shallow and has shown a number of areas that are important to study in more depth. One such area is advanced control strategy, which is necessary to mitigate the weakness of the technology (low temperature lift for cooling) and to optimally use its strength (storage).

Elbesparing med pelletkaminer och solv��rme i direktelv��rmda sm��hus

The aim of this study was to investigate how electricallyheated houses can be converted to using wood pellet and solarheating. There are a large number of wood pellet stoves on themarket. Many stoves have a water jacket, which gives anopportunity to distribute the heat to domestic hot water and aradiator heating system. Three typical Swedish houses with electric resistanceheating have been studied. Fourteen different system conceptsusing wood pellet stoves and solar heating systems have beenevaluated. The systems and the houses have been simulated indetail using TRNSYS. The houses have been divided in up to 10different zones and heat transfer by air circulation throughdoorways and open doors have been simulated. The pellet stoveswere simulated using a recently developed TRNSYS component,which models the start- and stop phases, emissions and thedynamic behaviour of the stoves. The model also calculates theCO-emissions. Simulations were made with one stove without awater jacket and two stoves with different fractions of thegenerated heat distributed in the water circuit. Simulations show that the electricity savings using a pelletstove are greatly affected by the house plan, the systemchoice, if the internal doors are open or closed and thedesired level of comfort. Installing a stove with awater-jacket connected to a radiator system and a hot waterstorage has the advantage that heat can be transferred todomestic hot water and be distributed to other rooms. Suchsystems lead to greater electricity savings, especially inhouses having a traditional layout. It was found that not allrooms needed radiators and that it was more effective in mostcases t use a stove with a higher fraction of the heatdistributed by the water circuit. The economic investigation shows that installing a woodpellet stove without a water jacket gives the lowest totalenergy- and capital costs in the house with an open plan (fortoday's energy prices and the simulated comfort criteria). Inthe houses with a traditional layout a pellet stove givesslightly higher costs than the reference house having onlyelectrical resistance heating due to the fact that less heatingcan be replaced. The concepts including stoves with a waterjacket all give higher costs than the reference system, but theconcept closest to be economical is a system with a bufferstore, a stove with a high fraction of the heat distributed bythe water circuit, a new water radiator heating system and asolar collector. Losses from stoves can be divided into: flue gas lossesincluding leakage air flow when the stove is not in operation;losses during start and stop phases; and losses due to a highair factor. An increased efficiency of the stoves is importantboth from a private economical point of view, but also from theperspective that there can be a lack of bio fuel in the nearfuture also in Sweden. From this point of view it is alsoimportant to utilize as much solar heat as possible. Theutilization of solar heat is low in the simulated systems,depending on the lack of space for a large buffer store. The simulations have shown that the annual efficiency ismuch lower that the nominal efficiency at full power. Thesimulations have also shown that changing the control principlefor the stove can improve efficiency and reduce theCO-emissions. Today's most common control principle for stovesis the on/off control, which results in many starts and stopsand thereby high CO-emissions. A more advanced control varyingthe heating rate from maximum to minimum to keep a constantroom temperature reduces the number of starts and stops andthereby the emissions. Also the efficiency can be higher withsuch a control, and the room temperature will be kept at a moreconstant temperature providing a higher comfort.

Combined solar and pellet heating systems for single-family houses : How to achieve decreased electricity usage, increased system efficiency and increased solar gains

In Sweden, there are about 0.5 million single-family houses that are heated by electricity alone, and rising electricity costs force the conversion to other heating sources such as heat pumps and wood pellet heating systems. Pellet heating systems for single-family houses are currently a strongly growing market. Future lack of wood fuels is possible even in Sweden, and combining wood pellet heating with solar heating will help to save the bio-fuel resources. The objectives of this thesis are to investigate how the electrically heated single-family houses can be converted to pellet and solar heating systems, and how the annual efficiency and solar gains can be increased in such systems. The possible reduction of CO-emissions by combining pellet heating with solar heating has also been investigated. Systems with pellet stoves (both with and without a water jacket), pellet boilers and solar heating have been simulated. Different system concepts have been compared in order to investigate the most promising solutions. Modifications in system design and control strategies have been carried out in order to increase the system efficiency and the solar gains. Possibilities for increasing the solar gains have been limited to investigation of DHW-units for hot water production and the use of hot water for heating of dishwashers and washing machines via a heat exchanger instead of electricity (heat-fed appliances). Computer models of pellet stoves, boilers, DHW-units and heat-fed appliances have been developed and the parameters for the models have been identified from measurements on real components. The conformity between the models and the measurements has been checked. The systems with wood pellet stoves have been simulated in three different multi-zone buildings, simulated in detail with heat distribution through door openings between the zones. For the other simulations, either a single-zone house model or a load file has been used. Simulations were carried out for Stockholm, Sweden, but for the simulations with heat-fed machines also for Miami, USA. The foremost result of this thesis is the increased understanding of the dynamic operation of combined pellet and solar heating systems for single-family houses. The results show that electricity savings and annual system efficiency is strongly affected by the system design and the control strategy. Large reductions in pellet consumption are possible by combining pellet boilers with solar heating (a reduction larger than the solar gains if the system is properly designed). In addition, large reductions in carbon monoxide emissions are possible. To achieve these reductions it is required that the hot water production and the connection of the radiator circuit is moved to a well insulated, solar heated buffer store so that the boiler can be turned off during the periods when the solar collectors cover the heating demand. The amount of electricity replaced using systems with pellet stoves is very dependant on the house plan, the system design, if internal doors are open or closed and the comfort requirements. Proper system design and control strategies are crucial to obtain high electricity savings and high comfort with pellet stove systems. The investigated technologies for increasing the solar gains (DHW-units and heat-fed appliances) significantly increase the solar gains, but for the heat-fed appliances the market introduction is difficult due to the limited financial savings and the need for a new heat distribution system. The applications closest to market introduction could be for communal laundries and for use in sunny climates where the dominating part of the heat can be covered by solar heating. The DHW-unit is economical but competes with the internal finned-tube heat exchanger which is the totally dominating technology for hot water preparation in solar combisystems for single-family houses.

Fj��rrv��rmedrivna vitvaror : Erfarenheter fr��n utveckling, installationer och kostnadsber��kningar

V��rmedrivna vitvaror eller HWC-maskiner som de kallas av tillverkaren v��rms med varmt vatten fr��n en cirkulerande krets via en v��rmev��xlare inbyggd i maskinen, till skillnad fr��n konventionella maskiner som v��rms med el. Denna teknik skall inte f��rv��xlas med maskiner som ��r anslutna till varmvattenledningen och fylls p�� med varmt vatten och som d��rmed begr��nsas till disk- och tv��tt. Syftet med fj��rrv��rmedrivna vitvaror ��r allts�� att anv��nda fj��rrv��rme, som har l��gre kvalitet och pris ��n elenergi f��r uppv��rmning och torkning och p�� s�� s��tt spara el och ut��ka fj��rrv��rmeunderlaget. En j��mf��relse av koldioxidutsl��pp och prim��renergianv��ndning mellan konventionella vitvaror och fj��rrv��rmedrivna vitvaror visar att b��de koldioxidutsl��pp och prim��renergianv��ndning blir l��gre f��r fj��rrv��rmedrivna vitvaror om biobr��nsle anses koldioxidneutralt och den el som ers��tts ��r producerad i kolkraftverk eller gaskombikraftverk. �� Denna rapport beskriver utveckling och kommersialisering av v��rmedrivna vitvaror (disk- och tv��ttmaskiner samt torktumlare och torksk��p) och hur de kan anslutas mot fj��rrv��rmesystem i olika systeml��sningar. Dessutom har de energim��ssiga och ekonomiska f��ruts��ttningarna f��r tekniken unders��kts. Erfarenheterna fr��n f��ltprovning ��r dock mycket begr��nsade, eftersom de byggen d��r f��lttesterna skulle ske f��rsenades. Under 2013 f��rdigst��lls ett flerbostadshus med v��rmedrivna vitvaror i 160 l��genheter i V��ster��s. �� De utvecklade maskinernas v��rmeanv��ndning som andel av total energianv��ndning vid 60 graders framledningstemperatur har uppm��tts till ca 50 % f��r diskmaskinen, 67 % f��r tv��ttmaskinen, 80 % f��r torktumlaren och 93 % f��r torksk��pet. I det studerade flerbostadshuset av passivhusstandard uppg��r lasten fr��n v��rmedrivna vitvaror komfortgolvv��rme och handdukstorkar till upp mot 30 % av husets totala v��rmeanv��ndning. F��r sm��hus ��r motsvarande siffra upp mot 20 %. Att anv��nda fj��rrv��rme ist��llet f��r elv��rme till dessa installationer som normalt ��r elv��rmda kan allts minska elbehovet betydligt i l��genergibebyggelse vilket ocks�� minskar b��de koldioxidutsl��ppen och prim��renergianv��ndningen. �� Ekonomiska analyser har genomf��rts f��r tv�� olika systemkoncept (separat vitvarukrets och V��ster��smodellen) f��r nybyggda sm��husomr��den och flerfamiljshus d��r fj��rrv��rme inte bara anv��nds till vitvaror utan ocks�� till handdukstorkar och komfortgolvv��rme. De ekonomiska analyserna visar att V��ster��smodellen ��r den mest ekonomiskt intressanta systeml��sningen med v��rmedrivna vitvaror, handdukstork och komfortgolvv��rme. I flerfamiljshus kan den vara konkurrenskraftig mot de elv��rmda alternativen (konventionellt system med eldrivna vitvaror, komfortgolvv��rme och handdukstorkar) om prisskillnaden mellan el och fj��rrv��rme ��r st��rre ��n 0,7 kr/kWh. En parameterstudie visar att kapitalkostnaden blir ganska h��g j��mf��rt med energikostnaden, vilket betyder att l��ng livsl��ngd och m��nga cykler ��r viktigt f��r att f��rb��ttra de ekonomiska f��ruts��ttningarna f��r v��rmedrivna vitvaror. F��r passiva sm��hus blir kostnaden f��r V��ster��smodellen med v��rmedrivna vitvaror, handdukstork och komfortgolvv��rme likv��rdig med de elv��rmda alternativen vid energiprisskillnader p�� 0,7 kr/kWh inklusive moms, medan det kr��vs prisskillnader p�� 0,9 kr/kWh inklusive moms f��r normalisolerade sm��husomr��den. �� Sammanfattningsvis kan s��gas att i kommuner med ett konkurrenskraftigt fj��rrv��rmepris finns det viss l��nsamhet f��r hela konceptet enligt V��ster��smodellen med v��rmedrivna vitvaror, komfortgolvv��rme, och handdukstorkar. Om man d��remot ser p�� konkurrensen f��r enskilda vitvaror ��r det fr��mst torktumlaren som ��r konkurrenskraftig i bost��der. M��lpriset p�� 1000 kr extra f��r v��rmedrift har inte kunnat uppn��s inom projektet f��r diskmaskiner och tv��ttmaskiner. Det kr��vs l��gre priser och l��ga anslutningskostnader f��r att r��kna hem diskmaskinen och tv��ttmaskinen som enskilda komponenter. �� V��rmedrivna tv��ttmaskiner och torktumlare ��r konkurrenskraftiga i flerfamiljstv��ttstugor. Speciellt i de fall d��r bel��ggningen ��r god och flera maskiner delar p�� anslutningskostnaden till fj��rrv��rmecentralen kan v��rmedrift bli riktigt l��nsam. Torksk��pens konkurrenskraft har inte kunnat utv��rderas, d�� priset ��nnu inte fastst��llts. Att anv��nda VVC-systemet f��r v��rmedistribution till v��rmedrivna vitvaror kan vara mycket intressant, men det kr��ver att legionellaproblematiken kan l��sas. I nul��get finns ingen l��sning som uppfyller formuleringarna i boverkets byggregler. Ett annat distributionss��tt som kan vara intressant, men som inte unders��kts i studien ��r att anv��nda VVC f��r varmvattendistribution och en gemensam radiator- och vitvarukrets med konstant framledningstemperatur. Den akt��r som f��rv��ntas ha st��rst ekonomiskt intresse av att tekniken implementeras ��r sannolikt fj��rrv��rmebolagen som f��r s��lja mer v��rme och det ligger d��rmed fr��mst p�� deras ansvar att marknadsf��ra tekniken i m��tet med sina kunder.

V��rd i livets slut av personer med demens. Personal och anh��rigas upplevelse av given v��rd : En metasyntes

Palliativt f��rh��llningss��tt k��nnetecknas av helhetssyn av m��nniskan och uppn��s genom st��ttning av individen att leva med v��rdighet och st��rsta m��jliga v��lbefinnande till livets slut oavsett diagnos eller ��lder. Demens ��r en sjukdom som ��r sv��rt handikappande f��r den som drabbas och f��r de anh��riga ��r sjukdomen f��r��dande. Den palliativa v��rden av personer med demens ��r inte optimerad. Studier visar att det dels beror p�� demenssjukdomen som ��r sv��r att v��rda och dels f��r att st��d till de personer som v��rdar sina anh��riga och det sociala kommunala n��tverket har brister. Syfte: Att analysera upplevelsen av given v��rd i livets slutskede hos personer med demensdiagnos ur personalens och anh��rigas perspektiv. Metod: Metasyntes utf��rd med Howell Major och Savin-Badins analysmodell, Qualitative Research Synthesis. Resultat: Kunskap och personcentrering var de tv�� begrepp som blev produkten av syntesen. Begreppen fungerar som motsatser, om det finns kunskap och personcentrering s�� finns en bra upplevelse av given v��rd hos personal och anh��riga och om det brister i kunskap och personcentrering blir upplevelsen s��mre. Diskussion: Kunskap om demens bland personal har i syntesen visats vara en indikator f��r god v��rd vid livets slut. Utbildning i demenssjukdom b��r ske kontinuerligt och p�� olika niv��er beroende p�� vilken personalkategori som utbildas. Konklusion: Palliativ v��rd och demens m��ste f�� utrymme i utbildningarna av all personal, fr��n undersk��terska till specialistl��kare.

Passive solar options for reducing heating demand and maintain indoor climate in a multifamily house in Sweden

This research was carried out by studying possible renovation of a two-storey detached multifamily building by using passive solar design options in a cold climate in Borl��nge, Sweden where the heating Degree Days are 4451 (base 20��C). Borl��nge`s housing company, Tunabyggen, plans to renovate the project house located inthe multicultural district, Jakobsg��rdarna. The goal of the thesis was to suggest a redesign of the current building, decrease the heating energy use, by applying passive solar design and control strategies, in a most reasonable way. In addition ensure a better thermal comfort for the tenants in the dwellings. Literatures have been studied, from which can be inferred that passive design should be abasic design consideration for all housing constructions, because it has advantages to ensure thermal comfort, and reduce the energy use. In addition further savings can be achieved applying different types of control strategies, from which the house will be more personalized, and better adapted to the user���s needs.The proposed method is based on simulations by using TRNSYS software. First a proper building model was set up, which represents the current state of the project building. Then the thermal insulation and the windows were upgraded, based on today's building regulations. The developments of the passive solar options were accomplished in two steps. First of all the relevant basic passive design elements were considered, then those advantages were compared to the advantages of applying new conventional thermostat, and shading control strategies.The results show that there is significant potential with the different types of passive solar design; their usage depends primarily on the location of the site as well as the orientation of the project building. Applying the control strategies, such as thermostat, and shading control, along the thermal insulation upgrade, may lead to significant energy savings (around 40 %), by comparison to the reference building without any upgrade.

System Integration of PV/T Collectors in Solar Cooling Systems

The demand for cooling and air-conditioning of building is increasingly ever growing. This increase is mostly due to population and economic growth in developing countries, and also desire for a higher quality of thermal comfort. Increase in the use of conventional cooling systems results in larger carbon footprint and more greenhouse gases considering their higher electricity consumption, and it occasionally creates peaks in electricity demand from power supply grid. Solar energy as a renewable energy source is an alternative to drive the cooling machines since the cooling load is generally high when solar radiation is high. This thesis examines the performance of PV/T solar collector manufactured by Solarus company in a solar cooling system for an office building in Dubai, New Delhi, Los Angeles and Cape Town. The study is carried out by analyzing climate data and the requirements for thermal comfort in office buildings. Cooling systems strongly depend on weather conditions and local climate. Cooling load of buildings depend on many parameters such as ambient temperature, indoor comfort temperature, solar gain to the building and internal gains including; number of occupant and electrical devices. The simulations were carried out by selecting a suitable thermally driven chiller and modeling it with PV/T solar collector in Polysun software. Fractional primary energy saving and solar fraction were introduced as key figures of the project to evaluate the performance of cooling system. Several parametric studies and simulations were determined according to PV/T aperture area and hot water storage tank volume. The fractional primary energy saving analysis revealed that thermally driven chillers, particularly adsorption chillers are not suitable to be utilizing in small size of solar cooling systems in hot and tropic climates such as Dubai and New Delhi. Adsorption chillers require more thermal energy to meet the cooling load in hot and dry climates. The adsorption chillers operate in their full capacity and in higher coefficient of performance when they run in a moderate climate since they can properly reject the exhaust heat. The simulation results also indicated that PV/T solar collector have higher efficiency in warmer climates, however it requires a larger size of PV/T collectors to supply the thermally driven chillers for providing cooling in hot climates. Therefore using an electrical chiller as backup gives much better results in terms of primary energy savings, since PV/T electrical production also can be used for backup electrical chiller in a net metering mechanism.

Performance evaluation of ventilation radiators

A ventilation radiator is a combined ventilation and heat emission unit currently of interest due to its potential for increasing energy efficiency in exhaust ventilated buildings with warm water heating. This paper presents results of performance tests of several ventilation radiator models conducted under controlled laboratory conditions. �� The purpose of the study was to validate results achieved by Computational Fluid Dynamics (CFD) in an earlier study and indentify possible improvements in the performance of such systems. The main focus was on heat transfer from internal convection fins, but comfort and health aspects related to ventilation rates and air temperatures were also considered. �� The general results from the CFD simulations were confirmed; the heat output of ventilation radiators may be improved by at least 20 % without sacrificing ventilation efficiency or thermal comfort. �� Improved thermal efficiency of ventilation radiators allows a lower supply water temperature and energy savings both for heating up and distribution of warm water in heat pumps or district heating systems. A secondary benefit is that a high ventilation rate can be maintained all year around without risk for cold draught.

Influence of hydraulics and control of thermal storage in solar assisted heat pump combisystems

This paper studies the influence of hydraulics and control of thermal storage in systems combined with solar thermal and heat pump for the production of warm water and space heating in dwellings. A reference air source heat pump system with flat plate collectors connected to a combistore was defined and modeled together with the IEA SHC Task 44 / HPP Annex 38 (T44A38) ���Solar and Heat Pump Systems��� boundary conditions of Strasbourg climate and SFH45 building. Three and four pipe connections as well as use of internal and external heat exchangers for DHW preparation were investigated as well as sensor height for charging of the DHW zone in the store. The temperature in this zone was varied to ensure the same DHW comfort was achieved in all cases. The results show that the four pipe connection results in 9% improvement in SPF compared to three pipe and that the external heat exchanger for DHW preparation leads to a 2% improvement compared to the reference case. Additionally the sensor height for charging the DHW zone of the store should not be too low, otherwise system performance is adversely affected

The effects of attitudes and personality traits on mode choice

We hypothesise that differences in people's attitudes and personality traits lead them to attribute varying importance to environmental considerations, safety, comfort, convenience and flexibility. Differences in personality traits call be revealed not only in the individuals' choice of transport, but also in other actions of their everyday lives-such as how much they recycle, whether they take precautions or avoid dangerous pursuits. Conditioning on a set of exogenous individual characteristics, we use indicators of attitudes and personality traits to form latent variables for inclusion in an, otherwise standard, discrete mode choice model. With a sample of Swedish commuters, we find that both attitudes towards flexibility and comfort, as well as being pro-environmentally inclined, influence the individual's choice of mode. Although modal time and cost still are important, it follows that there are other ways, apart from economic incentives, to attract individuals to the, from society's perspective, desirable public modes of transport. Our results should provide useful information to policy-makers and transportation planners developing sustainable transportation systems.

Radiation properties of coil-coated steel in building envelope surfaces and the influence on building thermal performance

Recent studies have shown that the optical properties of building exterior surfaces are important in terms of energy use and thermal comfort. While the majority of the studies are related to exterior surfaces, the radiation properties of interior surfaces are less thoroughly investigated. Development in the coil-coating industries has now made it possible to allocate different optical properties for both exterior and interior surfaces of steel-clad buildings. The aim of this thesis is to investigate the influence of surface radiation properties with the focus on the thermal emittance of the interior surfaces, the modeling approaches and their consequences in the context of the building energy performance and indoor thermal environment. The study consists of both numerical and experimental investigations. The experimental investigations include parallel field measurements on three similar test cabins with different interior and exterior surface radiation properties in Borl��nge, Sweden, and two ice rink arenas with normal and low emissive ceiling in Lule��, Sweden. The numerical methods include comparative simulations by the use of dynamic heat flux models, Building Energy Simulation (BES), Computational Fluid Dynamics (CFD) and a coupled model for BES and CFD. Several parametric studies and thermal performance analyses were carried out in combination with the different numerical methods. The parallel field measurements on the test cabins include the air, surface and radiation temperatures and energy use during passive and active (heating and cooling) measurements. Both measurement and comparative simulation results indicate an improvement in the indoor thermal environment when the interior surfaces have low emittance. In the ice rink arenas, surface and radiation temperature measurements indicate a considerable reduction in the ceiling-to-ice radiation by the use of low emittance surfaces, in agreement with a ceiling-toice radiation model using schematic dynamic heat flux calculations. The measurements in the test cabins indicate that the use of low emittance surfaces can increase the vertical indoor air temperature gradients depending on the time of day and outdoor conditions. This is in agreement with the transient CFD simulations having the boundary condition assigned on the exterior surfaces. The sensitivity analyses have been performed under different outdoor conditions and surface thermal radiation properties. The spatially resolved simulations indicate an increase in the air and surface temperature gradients by the use of low emittance coatings. This can allow for lower air temperature at the occupied zone during the summer. The combined effect of interior and exterior reflective coatings in terms of energy use has been investigated by the use of building energy simulation for different climates and internal heat loads. The results indicate possible energy savings by the smart choice of optical properties on interior and exterior surfaces of the building. Overall, it is concluded that the interior reflective coatings can contribute to building energy savings and improvement of the indoor thermal environment. This can be numerically investigated by the choice of appropriate models with respect to the level of detail and computational load. This thesis includes comparative simulations at different levels of detail.

To achieve safe and respectful maternity care in tertiary level hospitals in Nepal, relatives are a valued addition to the provision of maternity care

Introduction: The White Ribbon Alliance for safe motherhood believes respectful maternity care is the universal right of every childbearing woman. Methods: NHRC in 2012 approved an inquiry of respectful care at facility-based childbirth. Individual-, focus group interviews and content analysis was used for gathering and analysis of data. Findings: The participating women and the SBAs shared similar views, and this was that together the SBAs and relatives ensured the women remained within the comfort and safety zone when giving birth in a tertiary level maternity unit. Conclusion: The SBAs strategy of having relatives provides basic care alongside the provision of medical care by the SBAs is a strategy that Nepal could use to improve the quality of its maternity care without any additional costs. Clinical implication: Prenatal classes might contribute to preparing relatives. Further Research: Further research could evaluate such a strategy in order to determine its effectiveness in reduction of morbidity and mortality.