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Thesis. 1976. M.Arch.--Massachusetts Institute of Technology. Dept. of Architecture. / Microfiche copy available in Archives and Rotch. / Bibliography: leaves 171-174. / by David W. Brown. / M.Arch.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016. / The performance of a wall Mounted space comfort heater has been studied with respect to the geometry of its mounting condition. Tests were conducted in a laboratory with the heater positioned at various heights from the floor and the channel that is created by the various gaps with the wall on which the heater was mounted. Tests were also performed with the heater mounted on the wall whose emissivity was adjusted to low, medium and high values as well as placing insulation material on the wall directly behind the heater. The outcome of the experiments revealed an acceptable geometry of the heater’s mounting at least 200 mm above the floor, and 50 mm off-set from the wall. The results of the heater mounted against the wall revealed a drop in performance as compared to the heater’s “benchmark” performance when it was freely standing on the floor of the laboratory; with an efficiency of about 41% (almost evenly shared by each face). This efficiency, which is based on the convective heat transfer generated by the heater’s warm/hot surfaces, is relative to the electrical energy input and it dropped when the heater was mounted against a grey wall to around 35%, of which only 26% was produced inside the channel. The heat transfer by radiation from the heater’s surface is treated as net loss to the walls of the room/enclosure.The performance of the heater when mounted against the wall improved almost to the benchmark value when the wall behind the heater was made refelective (low emissivity). It is recommended that further research should be undertaken to thoroughly investigate the “mode” of heat transfer, by the induced flow through the channel, in a more formal or scientific modelling approach.

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O emprego de sistemas passivos de condicionamento de ambientes ao invés de equipamentos de climatização artificial pode ser uma solução bastante conveniente para diminuir o gasto de eletricidade e melhorar o conforto térmico de uma edificação. Uma das técnicas usadas para a melhoria do desempenho térmico de edificações é a utilização de “Paredes Trombe”. Este é um sistema de climatização passiva que utiliza ganhos solares associados à inércia térmica de uma parede para absorver calor no período frio sem bloquear suas perdas do período quente. Esta pesquisa tem como objetivo analisar o potencial de aquecimento/resfriamento de um sistema de climatização passiva baseado na utilização de uma Parede Trombe. Para isso, foram construídos dois protótipos em escala reduzida, sendo um deles com Parede Trombe e o outro em alvenaria de blocos de concreto, sem o sistema passivo. As medições ocorreram em períodos frios (datas) de 2011 e no período de verão de 2012, para configurações distintas da Parede Trombe. Os resultados mostraram que a Parede Trombe teve um resultado positivo tanto para o inverno quanto para o verão. / The use of passive solar heating for achieving thermal comfort inside a building is a very convenient solution to reduce the cost of electricity. One of the techniques used to improve the thermal performance of buildings is using "Trombe Walls." This is a passive solar heating system that uses solar gains associated with the thermal inertia of a wall to absorb heat during cold periods without blocking their loss in the warm period. This research aims to analyze the potential for heating and cooling of a Trombe Wall. For this, two cells were built on a small scale: passive solar cell and a reference cell. The measurements took place in cold periods (dates), of 2011 and during the summer of 2012, for different configurations of the Trombe Wall. The results showed that the Trombe Wall had a positive result for both winter and summer.

Due to rising energy costs and concerns about global climate change, high performance buildings are more in demand than ever before. With roughly 20% of the total energy consumption in the United States being devoted to residential use, this sector represents a significant opportunity for future savings. There are many guidelines and standards for reducing building energy consumption. One of the most stringent is the Passive House Standard. The standard requires that that air infiltration is less than or equal to 0.6 air changes per hour at a 50 Pascal pressure difference (ACH 50), annual heating energy is less than or equal to 15kWh/m2, and total annual source energy is less than or equal to 120 kWh/m2. For comparison, the typical West coast US residence has an ACH50 of 5 and annually uses more than 174 kWh/m2 of source energy according to the 2009 Residential Energy Consumption Survey. With these challenging requirements, successful implementation of the Passive House Standard requires effective strategies to substantially reduce energy consumption for all end uses. Heating and cooling loads are low by necessity in a Passive House. As such this makes end uses like water heating a much larger fraction of total energy use than they would be in a typical building. When air to water heat pumps are employed the energy consumption by water heating is lowered significantly. By employing innovative heat recovery strategies the energy consumption for water heating and HVAC can be reduced even further. This study uses energy modeling and project cost analysis to evaluate three innovative control strategies. Results for a Passive House in Portland Oregon show a savings of about $70 annually with a payback period of 10 years. The same Passive House in Fairbanks Alaska with a different strategy would save $150 annually with a payback period of 5 years.