The main objectives of this thesis have been to evaluate how, under which premises, and to what extent building thermal mass can contribute to reduce the net energy demand in office buildings. The thesis also assesses the potential thermal environmental benefits of utilizing thermal mass in office buildings, i.e. reduction of temperature peaks, reduction of temperature swings, and the reduction in the number of hours with excessive operative temperatures. This has been done by literature searches, and experimental and analytical assessments. This thesis mainly concerns office buildings in the Norwegian climate. However, the methods used and the results obtained from this work are transferable to other countries with similar climates and building codes. Within the limitations of this thesis and based on the findings from all parts and papers this thesis comprises, it is shown that utilization of thermal mass in office buildings reduces the daytime peak temperature, reduces the diurnal temperature swing, decreases the number of hours with excessive temperatures, and increases the ability of a space to handle daytime heat loads. Exposed thermal mass also contributes to decrease the net cooling demand in buildings. However, thermal mass is found to have only a minor influence on the heating demand in office buildings. The quantity of the achievements is dependent on the amount of exposed thermal mass, night ventilation strategy, and airflow rates. In addition, parameters such as set point temperatures, control ranges, occupancy patterns, daytime ventilation airflow rates, and prevailing convection regimes are influential for the achieved result. The importance of these parameters are quantified and discussed. / Hovedmålene med denne avhandlingen har vært å evaluere hvordan, under hvilke forutsetninger og i hvilken utstrekning termisk masse kan bidra til å redusere netto energibehov i kontorbygninger. Avhandlingen vurderer også hvilke potensielle fordeler termisk masse har for det termiske inneklimaet, dvs. reduksjon av maksimumstemperatur, temperatursvingninger og antall timer med overtemperaturer. Disse undersøkelsene er gjort gjennom søk i litteraturen, feltstudier og analytiske metoder. Avhandlingen omfatter i hovedsak kontorbygninger under norske forhold, men metodene og resultatene er overførbare til andre land med sammenlignbare klimatiske forhold og byggeskikk. Innenfor avgrensningene gjort i avhandlingen og basert funnene i de ulike delene og artiklene avhandlingen består av, er det vist at utnyttelse av termisk masse i kontorbygg bidrar til å redusere netto energibehov. Termisk masse reduserer også maksimumstemperaturen dagtid, demper temperaturvariasjonene over døgnet og reduserer antall timer med overtemperaturer. Utnyttelse av termisk masse bidrar også til at rom kan tåle en høyere intern varmelast enn lette rom uten at dette går ut over den termiske komforten. Termisk masse har imidlertid liten betydning for energibehovet for oppvarming i kontorbygg. Gevinsten med å utnytte termisk masse avhenger av tilgjengeligheten av eksponerte tunge materialer, strategi for nattventilasjon og ventilasjonsluftmengder. I tillegg innvirker parametere som settpunkttemperaturer, dødbånd og kontrollintervaller for ventilasjonen og bruksmønster. Innvirkningen av disse parametrene er diskutert og kvantifisert.

The aim of this study was to evaluate the effects of environmental design parameters on thermal comfort conditions in the METU Faculty of Architecture Building located in Ankara. The building had some problems in terms of indoor climatic conditions, both in winter and in summer. It was evident that some design parameters caused this undesirable situation. The study therefore focused on understanding and evaluating the effects of design-dependent elements such as thermal mass, the size and orientation of windows, shading and vegetation on thermal comfort conditions in the case study building. While conducting this study, data loggers were used to record temperature and humidity data in predetermined rooms. Data was collected during certain periods in July, August, and September 2006. The data collected was analyzed statistically and hypotheses were tested using ANOVA. This study showed that the effect of thermal mass was almost the same for the rooms investigated owing to the fact that the entire building had been constructed with concrete curtain walls. In terms of thermal performance the number and orientation of the exterior walls, orientation and size of windows, room heights and also sun shading with surrounding vegetation were most effective design parameters for the rooms investigated

The use of sunlight has always been a major goal in the design and operation of commercial buildings to minimize electrical consumption of artificial lighting systems. Glazing systems designed to allow optimal visible light transmission also allow significant unwanted direct solar heat gain caused by infrared light. Conversely, glazing systems that are designed to reflect unwanted direct solar heat gain significantly reduce the transmittance of visible light through windows. The goal of this research was to characterize the performance of water as gap-fill for double-glazing units in eliminating the compromises that exist in current glazing systems with respect to light and heat transmittance. An in situ test approach and computer simulations were conducted to measure the performance of water-filled glazing units against air-filled glazing units. The thermal transmittance and solar heat gain coefficient values obtained from both the field experiments and computer simulations, glazing units with air-fill proved better than the glazing units with non-flowing water-fill. However, the high convective coefficient and the high thermal mass of the water can be used to its advantage when it is allowed to flow at peak temperatures, thus, maintaining lower temperature swings indoor. This can lead to a reduction of about 50-70% direct solar heat and still maintain high visibility.

As the rest of the world under development catches up economically with the developed nations, adoption of western tastes is projected to lead to enormous increases in energy use. Specifically, air conditioning use within countries with low saturation rates and high cooling degree rates (India and China) have a potential demand of up to 5 times that of the U.S. market. This growth in HVAC (Heating Ventilation&Air Conditioning) means billions of tons of increased carbon dioxide emissions and trillions of dollars in investment in electricity generation and transmission infrastructure.If there is adoption of Earth sheltering and integration design within these geographical areas, then it might be possible to mitigate the need for such high increase in electricity demand.Ultimately, an estimate of how much quantifiable impact wide adoption of earth integration can have in the regions in question needs to be calculated and compared to projected energy demand if things continue as they are. To do so, parameters need to be determined to see how much of the future air conditioning demand can be met through thermal mass/earth integration. That is, how much future energy demand can be avoided through earth sheltering? To do so:1-Determine what areas account for the greatest projected demand in future air conditioning use.2-See how much of the projected demand can be met through Thermal Mass and Earth Integration (T.M./E.I.) within these areas.3-A design/energy modeling exercise showing proper use and implementation of Earth sheltering within our local climate will be carried out to prove effectiveness of varied strategic thermal mass applications.4-Compare the relative savings of different levels of Earth Integration to arrive at an average overall savings if universal adoption takes place.Top-down approach to energy savings (HVAC efficiency) is not enough to offset projected adoption and its impact on the local and global environments. Energy efficient design is necessary to deal with as much of the increase in projected demand as possible. The use of earth as a building material can be a powerful tool in the fight against increasing energy demands and accompanied destructive environmental effects and needs greater consideration and adoption.

Indiana University-Purdue University Indianapolis (IUPUI) / In this work we have designed and simulated a thermal bi-directional integrated circuit mass flow sensor. The approach used here was an extension to the gas flow model given by Mayer and Lechner. The design features high precision response received from analog integrated circuits. A computational fluid dynamic (CFD) model was designed for simulations with air and water Using COMSOL Multiphysics. Established mathematical models for the heat flow equations including CFD parameters were used within COMSOL simulation(COMSOL Multiphysics, Sweden). Heat pulses of 55 °C for a period of nearly 120 seconds and 50% duty cycles were applied as thermal sources to the flowstream. The boundary conditions of the heat equations at the solid (heating element) fluid interface were set up in the software for the thermal response. The hardware design included one heating element and two sensing elements to detect the bi-directional mass flow. Platinum sensors were used due to their linear characteristics within 0 ºC to 100 ºC range, and their high temperature coefficient(0.00385 Ω/Ω/ºC). Polyimide thinfilm heater was used as the heating element due to its high throughput and good thermal efficiency. Two bridge circuits were used to sense the temperature distribution in the vicinity of the sensing elements. Three high precision instrumentation low power amplifiers with offset voltage ~2.5μV (50μV max) were used for bridge signal amplification and the difference circuit. The difference circuit was used to indicate the flow direction. A LM555 timer chip was utilized to provide the heat pulse period. Simulation and experimental measurements for heat pulses with different amplitude (temperature) were in good agreement. Also, the sensitivity of the flow sensor was observed to remain unaffected with the change in the duty cycle of the heat operation mode.

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<p>Nowadays, office buildings often have large temperature variations during the day and building envelope acts as an energy storing mass and damp these effects and so Offices need more cooling because of internal heat sources. But we know that cooling is more expensive than heating and it uses the very good quality of energy sources (exergy). Controlled Active Mass (CAM) is new approach to absorb radiant heating and acts as a passive cooling device. It has direct cooling effect and reduces the peak load. CAM is a new cooling system design with applying the low energy sources and operates at water temperature close to room temperature and increase the efficiency of heat pumps and other systems.</p><p>In this project, we calculated the transient heat transfer analysis for CAM in a very well insulated test room with façade wall, Internal heat generators (such as Manikin, Computer simulator & lighting) and ventilation.</p><p>Then Polished (shiny) CAM constructed from Aluminum sheets with 0.003 m thickness. It is cube shape with 0.6 m length. This size of CAM is according to 2.5 times larger than human body volume and initial water temperature assumed near half of human body temperature. Then in order to more radiation damping (absorption) by CAM, it painted black (also based on color analysis in heat transfer calculation).</p><p>Some velocity and temperature measurement have been carried out on both polished CAM and black CAM, after visualization by smoke and Infrared Camera. And more cases tested to see the effect of façade wall, IHG’s and ventilation inlet temperature. Thermal comfort measurement also have been done for finding PMV, PPD and temperature equivalent for a seated person which is doing an office job with normal closing.</p><p>At the end results discussed which includes the effect of CAM in room, differences between polished CAM and black CAM and effect of main heat sources on both CAM types (Polished / Black).</p>

The aim of this study was to investigate the passive and active parameters affecting energy efficiency of two office buildings with sun spaces, namely the MATPUM Building and the Solar Building on the Middle East Technical University (METU) Campus, Ankara and the effect of sun spaces on temperature patterns within mentioned buildings. Both buildings were oriented in the same direction, namely south. However, the location and the type of the sunspaces differed from each other. The sun space in the MATPUM Building is an atrium which has southerly glazed fa&ccedil / ade. On the other hand, the sun space in the Solar Building is an enclosed conservatory which has southerly glazed fa&ccedil / ades and roof. The effect of sun spaces on temperature patterns within case study buildings was determined by collecting internal temperature and humidity data from different locations within the buildings and external temperature and humidity data on certain days of the week from May to August and October and November. Data loggers were used to collect these data. The collected data was then compared for the two buildings and also for the different months. In conclusion, more heat gain resulting in temperature increase inside the buildings was obtained in conservatories when compared to the atria which have glazed fa&ccedil / ade instead of glazed roof. This was also proved by the analysis of variance method which was used for the comparison of temperature data of two buildings

Nowadays, office buildings often have large temperature variations during the day and building envelope acts as an energy storing mass and damp these effects and so Offices need more cooling because of internal heat sources. But we know that cooling is more expensive than heating and it uses the very good quality of energy sources (exergy). Controlled Active Mass (CAM) is new approach to absorb radiant heating and acts as a passive cooling device. It has direct cooling effect and reduces the peak load. CAM is a new cooling system design with applying the low energy sources and operates at water temperature close to room temperature and increase the efficiency of heat pumps and other systems. In this project, we calculated the transient heat transfer analysis for CAM in a very well insulated test room with façade wall, Internal heat generators (such as Manikin, Computer simulator &amp; lighting) and ventilation. Then Polished (shiny) CAM constructed from Aluminum sheets with 0.003 m thickness. It is cube shape with 0.6 m length. This size of CAM is according to 2.5 times larger than human body volume and initial water temperature assumed near half of human body temperature. Then in order to more radiation damping (absorption) by CAM, it painted black (also based on color analysis in heat transfer calculation). Some velocity and temperature measurement have been carried out on both polished CAM and black CAM, after visualization by smoke and Infrared Camera. And more cases tested to see the effect of façade wall, IHG’s and ventilation inlet temperature. Thermal comfort measurement also have been done for finding PMV, PPD and temperature equivalent for a seated person which is doing an office job with normal closing. At the end results discussed which includes the effect of CAM in room, differences between polished CAM and black CAM and effect of main heat sources on both CAM types (Polished / Black).