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This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab. The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics. The background of the problem with moisture is that today’s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate. The contribution of moisture increases this problem when the relative humidity reaches 75 %, which in most cases promotes mould. Moisture comes with natural ventilation through the eaves due to outside humidity and precipitation finding its way in, and at the same time comes from the inside through openings or cracks on concrete slabs, ventilation ducts, and attic doors. Moisture also comes into the attic from building materials, especially from the concrete slabs that evaporate which gives off a lot of moisture throughout the years. These things are possible to prevent with four different methods ventilation, sealing, heating or insulating the outer roof. Moisture effects are calculated from the examples given by Roxull FuktFakta in comparison with the authors own calculations from other databases. The object of reference, Bergahojden 6, is a residential building that has served as a model for all the calculations. The conclusion shows that air circulation has to increase to get out the moisture through the ventilation. The winters here in Sweden are so humid that the ventilation should be suitable enough so that the humidity does not rise above 75 % in the attic. To heat up the attic with devices, or by using roof insulation, would bring the same climate as the outdated slab insulations. There will be a big loss of energy with heat going out if the roof is not insulated. To apply both systems would be a double investment which would be hard to convince builders of. The conclusion is that the best method would be to combine sealing with ventilation, or a possible mechanical system which allows the attic to be ventilated during the summer and sealed during the winter.

<p>This study was done regarding whether sealing or ventilation is the best solution to prevent moisture on cold attics. The authors of this report addressed the problem with moisture in attics when they started their cooperation with Peab.</p><p>The methods included interviews with people, database research, and calculations of a project in Akersberga north of Stockholm. The conclusion is based on interviews and other information as they are analyzed in relation to the house of reference. The focus of this report is on problems with moisture in the attics known as cold attics.</p><p>The background of the problem with moisture is that today’s slabs are usually insulated to save energy and that the attics nearly gives the climate as the outdoor climate. The contribution of moisture increases this problem when the relative humidity reaches 75 %, which in most cases promotes mould. Moisture comes with natural ventilation through the eaves due to outside humidity and precipitation finding its way in, and at the same time comes from the inside through openings or cracks on concrete slabs, ventilation ducts, and attic doors. </p><p>Moisture also comes into the attic from building materials, especially from the concrete slabs that evaporate which gives off a lot of moisture throughout the years. These things are possible to prevent with four different methods ventilation, sealing, heating or insulating the outer roof. </p><p>Moisture effects are calculated from the examples given by Roxull FuktFakta in comparison with the authors own calculations from other databases. The object of reference, Bergahojden 6, is a residential building that has served as a model for all the calculations. The conclusion shows that air circulation has to increase to get out the moisture through the ventilation. The winters here in Sweden are so humid that the ventilation should be suitable enough so that the humidity does not rise above 75 % in the attic. </p><p>To heat up the attic with devices, or by using roof insulation, would bring the same climate as the outdated slab insulations. There will be a big loss of energy with heat going out if the roof is not insulated. To apply both systems would be a double investment which would be hard to convince builders of. </p><p>The conclusion is that the best method would be to combine sealing with ventilation, or a possible mechanical system which allows the attic to be ventilated during the summer and sealed during the winter.</p>

The aim of this study was to contribute with further knowledge about children’s use of metaphors. In the study, 15 children at the age of two were interviewed during an experiment with condensation. In the interview the children were asked to describe the condensation to the interviewer. Most of the children were using subject relevant words, and a few were using pictorial descriptions. There was just one child that was using both pictorial descriptions and subject relevant words in their description of the condensation. The use of both categories can be interpreted as the child deliberately was using a metaphor and that shows, that even children as young as two years of age sometimes use metaphors. From a social constructivist perspective, language is the most important feature in acquiring knowledge, since knowledge is created in social interaction. Therefore the teachers in the younger years have an important role to guide and help children develop a nuanced language. Helping children understand, create and use metaphors in their interactions with others, and in their descriptions of phenomena, will help the children get a deeper sense of meaning in their quest to figure out the world around them. / Syftet med denna studie är att öka kunskapen kring de yngre barnens användande av metaforer i samtal kring experiment i naturvetenskaplig undervisning i förskolan. Ur ett socialkonstruktivistiskt perspektiv, är språket en nyckelfaktor i tillägnandet av ny kunskap, då kunskapen skapas i ett socialt sammanhang. Ur detta perspektiv är förskollärarnas roll som guider till ett nyanserat språk avgörande. När förskollärarna stöttar barnen till att inte bara förstå metaforer, utan även skapa egna och använda sig av dem i sina beskrivningar, hjälper de också barnen till att få en djupare förståelse för sin omgivning. I ett experiment med kondens intervjuades 15 barn i tvåårsåldern. De ombads beskriva sina observationer under experimentet för intervjuaren. De flesta barnen använde sig av ämnesrelevanta ord, och några använde sig av bildlika beskrivningar. Endast ett barn använde sig av både bildlika beskrivningar och ämnesrelevanta ord i sina beskrivningar av kondensen. Att barnet använde sig av båda kategorierna kan tolkas som att barnet medvetet använde sig av en metafor, vilket medför ett resultat som tyder på att det förekommer att även så unga barn, som barn i två års ålder använder sig av metaforer.

Denna rapport ingår i ett examensarbete på avancerad nivå inom ämnet produktutveckling.Arbetet innefattar en fallstudie som genomförts vid RTGA, Scania CV AB i Södertälje.Examensarbetet omfattar 30 högskolepoäng och har genomförts av undertecknad,teknologstudent från Mälardalens Högskola vårterminen 2015. Rapporten har upprättats i tvåversioner, en för Scania CV AB respektive en generell version där känslig företagsspecifikinformation har censurerats. I takt med att utvecklingen av motorprestanda fortskrider, med avseende på ökademotoreffekter samt teknikutveckling för emissionsreglering, så ökar också kravet på prestandaför kylsystem som måste klara av att kyla bort högre effekter. Fordonskombinationer medkraftfulla laddluftkylare löper dock stor risk att drabbas av utfälld kondens som fryser till is iladdluftkylaren vid låga omgivningstemperaturer. Isen medför ett tryckfall i laddluftkylarenmed prestandabortfall som följd. Scanias lösning till problematiken är en så kallad kylargardinsom syftar till att reducera kylluftflödet genom laddluftkylaren till den mån att isbildning intesker. Kylargardinen monteras manuellt av föraren framför kylarpaketet dåomgivningstemperaturen understiger 5 °C. Det finns även andra fördelar med att begränsa det yttre kylluftflödet som passerar genomkylarpaketet. Lastbilars kylsystem är i regel överdimensionerade för normala driftfall såsommotorvägskörning vilket betyder att maximal kylning inte krävs vid dessa situationer. Genomatt reducera det yttre kylluftflödet genom kylarpaketet så kan även hela fordonets totalaluftmotstånd reduceras vilket kan utnyttjas i syfte att reducera bränsleförbrukningen. För att erhålla en bra balansgång mellan aerodynamik och kylprestanda samt motverkaproblemet med isbildning i laddluftkylaren fanns därför en önskan om att en reglerbarkylartäckning skulle utvecklas för att kunna reglera kylluftflödet genom fordonets kylarpaketvid behov. Detta arbete innefattar en fallstudie där olika produktutvecklingsverktyg använts för att ta framolika konceptlösningar, anpassade för en specifik lastbil. Datorstödda flödessimuleringarutnyttjas för att utvärdera respektive verifiera konceptens funktion jämfört med olika referensmodeller. Resultatet visar bland annat att det slutgiltiga konceptets funktionsduglighet överensstämmermed den lösning som används idag samt att kylluftflödet inte påverkas nämnvärt då maximalkylkapacitet eftersträvas. Resultatet från den aerodynamiska flödessimuleringen indikerar ävenatt fordonets totala luftmotstånd kan reduceras med - Drag Counts (DC) vid hastigheten90 km/h och 0° vindriktning. Detta medför att bränsleförbrukningen i det specifika driftfallet,enligt tumregel, antas reduceras med - % för det specifika fordonet. / This report is part of a Master thesis project in the subject of Product Development. The workincludes a case study which was carried out at RTGA, Scania CV AB in Södertälje. The workcomprises 30 credits and was conducted by a student from Mälardalen University during thespring semester 2015. The report has been prepared in two versions; one for Scania CV AB anda generalized version where sensitive company specific information has been censored. The development of vehicle engine performance progresses in a rapid pace. This progressinclude increased engine power and improved technical features for emission control. This alsogoes for the requirement on performance of cooling systems in heavy trucks, which has tohandle dissipation of the increased power. Vehicles with powerful charge air coolers however,runs a high risk of being affected by iced condensation in the charge air cooler at low ambienttemperatures. The ice build-up results in a pressure drop in the charge air cooler with a loss ofengine performance as a consequence. Scania's solution to the problem is a so called radiatorblind designed to reduce the cooling air flow through the charge air cooler to the extent thatice build-up does not occur. The blind is mounted manually in front of the cooler package whenthe ambient temperature is expected to be below 5 °C. There are also other advantages to limit the outer cooling air flow passing through the coolingpackage. The cooling systems in heavy trucks are usually oversized for normal operatingconditions such as highway cruising, which means that maximum cooling is not required inthese situations. By reducing the airflow through the cooler package, the vehicle's total airresistance is reduced, which can be utilized in order to reduce fuel consumption. To obtain a good balance between aerodynamics and cooling performance, and to counteractthe problem of ice build-up in the charge air cooler, there was a desire for an adjustable radiatorcoverage which would be able to regulate the airflow through the vehicle's cooling packagewhen needed. This work includes a case study in which various product development tools are used toinvestigate different concept solutions, designated for a specific truck model. Computationalfluid dynamics (CFD) are used to evaluate and validate the concept’s functionality andcomparing them to different reference models. The results reveal that the final concept functionality is consistent with the one used today, andthat the cooling air flow is not significantly affected when maximum cooling capacity is strivedfor. The results of the aerodynamic flow simulation also indicate that the vehicle's total airresistance can be reduced by - Drag Counts (DC) at the speed of 90 km/h and 0° yaw angle.This means that fuel consumption in the specific operating case, as rule of thumb, is assumedto be reduced by - % for the specific vehicle.

Kondensbildning är ett stort problem i ishallar vilket leder till stora konsekvenser ifall det inte åtgärdas. Installation av ett avfuktningssystem är ett måste i ishallar men det betyder högre energianvändning. Denna studie undersöker hur RH-styrning (relativ fukthalt) för en avfuktare i PF Arenan lokaliserat i byn Lindefallet i Hudiksvalls kommun kan energieffektiviseras och samtidigt se till att kondensbildning undviks i ishallen. Kondensbildning i ishallar framkommer framförallt på takytan och isplanen. Kondens på isplanen sker när luftens absoluta luftfuktighet är större än den absoluta fuktigheten för isens gränsskikt. Eftersom isen har en temperatur under 0 °C så kommer vattnet att frysas på planen vilket åtgärdas genom att slipa isen med en ismaskin. Forskning visar att avfuktningsstyrning för att undvika kondens på isplanen leder till att avfuktaren blir överdimensionerad för att undvika takkondens. Konsekvenser för takkondens anses som mer allvarliga än de för kondens på isplanen, vilket har lett till att framtagning av ny styrning har fokuserat på att undvika takkondens. Mätningar har utförts i PF Arenans roterande sorptionsavfuktare och lufttillstånden inuti ishallen samt utomhus. Resultatet från mätningar används för att avgöra om det sker kondensbildning i ishallen. Olika styrstrategier jämförs med befintlig RH‑styrning för att fastställa vilka förbättringar som kan tillämpas. Resultat visar att vid stora personlaster och användning av ismaskinen leder till att takkondens framkommer under korta perioder. Samtidigt så går inte regenereringsbatteriet på maxeffekt under dessa perioder vilket betyder att avfuktningskapaciteten kan höjas. RH-styrning leder till överdimensionering i förhållande till båda kondensfenomenen under stora perioder, speciellt under kalla inomhustemperaturer. Föreslagen styrning går ut på att processluftens daggpunkt ska hållas två grader Celsius under takets yttemperatur. Styrningen kan definieras som en varierande daggpunktsstyrning. Det rekommenderas också att regenereringstemperaturen ökar ju mer börvärdet avviker från målfunktionen. Dock så analyserades inte en sådan ökning av regenereringstemperaturen i detalj. Det approximerades att ungefär 1 100 kWh el per månad kan sparas för avfuktaren motsvarande en energiminskning av 22 % gentemot den befintliga styrningen. Approximering förmodar att ismaskin slipar isen lika mycket med båda styrningarna och tar inte hänsyn till den ökade energianvändningen ifall högre regenereringstemperaturer tillämpas i avfuktaren. / Condensation is a major problem in ice rink arenas and if it is not resolved, will lead to construction damages. Generally, ice arenas use dehumidifiers to dehumidify the indoor air which causes an increase in energy use in the facility. This study investigates how the control strategy of the dehumidifier in the PF Arena localized in Lindefallet in Hudiksvall municipality can be improved to save energy while preventing the occurrence of condensation in the ice rink arena. Condensation in ice arenas occur on the ice surface and roof surface. Ice surface condensation occur if the indoor air humidity is higher than the humidity of the ice surface boundary layer. The ice will freeze the moisture onto the surface which require an ice resurfacer to flatten the playing field. Studies has shown that control strategies for dehumidification to prevent condensation on the ice surface results in oversizing of the dehumidifier for preventing condensation on the roof surface. And as condensation on roof surface leads to more serious consequences than that of ice surface condensation, it is of more interest to prevent the former. Measurements has been carried out on PF Arenan’s desiccant wheel dehumidifier and indoor as well as outdoor air. Results from measurements are used to analyze if any condensation occurs in the ice rink arena. Other control strategies are compared to the one used in PF Arenan to determine what improvements can be applied to the dehumidifier. Results show that during events and use of ice resurfacers some condensation on the roof surface occurs for short periods. During these periods, the regeneration heater does not use full power which could be used to increase the moisture removal capacity. The RH-control strategy results in oversizing for most hours when controlled to both condensation phenomenon, especially during cold temperatures. The recommended control strategy is to keep the dewpoint of the inlet process air 2 °C below the roof surface temperature. This control strategy is a type of variable dewpoint control function. It is also recommended to increase the regeneration temperature proportionally to the difference between the setpoint and the objective function. However, the results of this measure were not analyzed in detail. The new control strategy would approximately save 1 100 kWh per month over the current control function which amounts to an energy use decrease of 22 % for the dehumidifier. Assumed that behavior of ice resurfacing is not changed with the new control function and the approximation does not consider the increase of energy use if the regeneration temperature is increased.