The passive solar heated school in wallasey. III model studies of the thermal response of a passive school building

Using information on the dimensions and materials of a room in the Wallasey School, estimates are presented of its response to heat inputs due to the lighting system and the sun. The daily variation due to these influences is calculated using transient and harmonic approaches.     

The passive solar heated school in Wallasey. V. Energy requirements for A passive school building

The near-south-facing glazed wall of the Wallasey School admits large solar gains in sunny weather, sufficient to meet in full the heat need in cold weather. It permits large heat losses, however, and during dull weather, and during the long winter nights there is little or no compensating solar gain. The net effect of such glazing over a season might be either to save, or to waste energy as compared with a windowless building, according to the sunniness and coldness of the climate and the window characteristics. To examine the action of the glazing, use was made of 50 years of daily mean ambient temperature, and contemporary sunshine hours, in conjunction with the solar gain factor for the translucent and pinboarded areas of the solar wall, and for certain values of design temperature and ventilation rate. It is concluded that such glazing leads to modest savings, of around 5 to 10 W/m² daily average. Most of the saving appears to be achievable by around 30 per cent glazing; further glazed area tends to supply unwanted solar gain in sunny periods while increasing the losses in sunless conditions. The annual electricity consumptions are noted for the 20 year life of the building. Their costs suggest that the building has been economical to heat.     

The passive solar heated school in wallasey. IV. An observational study of the thermal response of a passive school building

An observational study on the Wallasey School has demonstrated its ability to maintain in most conditions of climate an equitable indoor climate both in regard to daily mean temperatures and daily variations, through use of solar gain and heat from the lights, and the appropriate control of ventilation. During occupied periods, air temperatures are usually between 17°C in winter and 23°C in sunny summer periods. The room provides a mainly ‘cold wall’ environment. The observational data and a series of model estimates have been compared. The general level of temperature within the building is known to depend strongly on ventilation rate, but since ventilation rate was not measured, steady-state comparisons as such are not possible. The observed and estimated temperature profiles for air and various surfaces including that of the furnishings during a very sunny period are in broad agreement. Analyses of the transient response of the structure in winter conditions has demonstrated a long response time (several days) describing the response of the enclosure, and a shorter response time of about half a day which describes the rate of settlement of internal temperature differences which may be initially present. Evidence is presented indicating low values for the convective heat transfer coefficient. An autocorrelational technique demonstrates that the thermal ‘memory’ of the classroom is much longer in winter than in summer. The response of the room during occupied and unoccupied periods is broadly similar, but conditions are rather more variable during occupation.     

Thermal modelling of a few novel solar collector-cum-storage units for passive heating

Analytical models have been put forward to predict the thermal performance of passive heating systems, which have previously been suggested. The systems consist of a water vessel for heat storage and a structure positioned on its outside wall, which act as a solar collector and a thermal insulation for the storage, respectively. Four different variations of structures have been considered and numerical calculations performed corresponding to the physical parameters of an earlier reported experimental study. The analysis is able to predict the experimental results fairly satisfactorily.     

The passive solar heated school in Wallasey. VIII a study of the lighting

The Wallasey School is recognized as an important building in the development of passive solar gain technology. This work reports an analysis of the lighting of the solar block of the school. A comprehensive photometric survey describes the visual environment of the school in both quantitative and qualitative terms. The results are compared with both statutory legislation and predictions using tools available to the original designers. Some general conclusions are drawn which emphasize the importance of visual aspects within the total design of passive solar technology buildings.     

Development of energy-efficient passive solar building design in Nicosia Cyprus

Analyses have been done on different techniques of passive solar control using local climatic data (for 25-year period) to obtain physical building design. Our main aim is to provide general and appropriate information at strategic pre-design stages to make better use of passive solar energy in urban planning and building design for better indoor ‘comfort’ climate. It utilizes manual analysis techniques or Mahoney tables and ACHIPAK to develop ‘comfort zones’, and ‘control potential zones’, for the Capital City of Nicosia (Cyprus). The use of the control potential zones (CPZs) in pre-design of buildings and their objectives are discussed. Opportunities and limitations of the pre-design guidelines are also discussed.     

The passive solar heated school in wallasey. I foreword and introduction

St. George's School, Wallasey, situated in the U.K. at latitude 53.4° N was designed so that equitable thermal conditions should be achieved within it using solar gains, heat from the lighting system and body heat from the children without the use of a conventional heating system. The building opened in 1962 and evoked considerable comment, both favourable and unfavourable, in the mid-sixties. This article briefly notes some of the comments and provides an account of some of the features which the architect incorporated to control the solar gains that enter through the large south-facing solar wall. Later articles in this series describe the findings of observational surveys carried out in the building.     

The passive solar heated school in wallasey. II background,preliminary analyses and patent specification

The Wallasey School is now recognized as an important building in the development of passive solar design. This article describes an enquiry into the origins of the building. It reviews such information as could have been known to the architect Mr. E. A. Morgan, at the time he was working on its design, and also discusses briefly such design techniques as are known to have been available to him. Some of his calculations, previously believed to have been associated with the building, are presented in detail. Morgan patented the design and an annotated version is given here. It is concluded that the architect had a good understanding of steady-state heat transfer in buildings but his handling of thermal storage was dubious. There is no direct evidence to suggest that Morgan could be assured that his construction would save, rather than waste, fuel for heating, but attention is drawn to results which indicate that a solar wall in that locality should save energy; Morgan could well have been aware of these findings.     

Solar passive heating through a thermosyphon air panel

Thermosyphon air panels installed on the south wall of a building are being used for solar space heating in the cold desert climates of North India. This paper presents a simulation model to predict the performance of such panels; a numerical evaluation of the performance has been made, using the meteorological data for January (having maximum and minimum temperatures equal to ?2·°C and ?14·2°C, respectively, and an insolation of 4·58 kWh/m² day on the horizontal surface). For typical weather condition in January a 1·62 m² thermosyphon air panel is seen to collect about 2·3 kWh of energy per day with a rise of temperature of about 2·5°C to 13·5°C (with room air at 18°C as inlet air) and a working efficiency of approximately 32·5 per cent.     

The passive solar heated school in Wallasey. VII. Window opening behaviour and the microclimate of a classroom

Previous work on factors which influence the opening or closing of windows suggests that at low ambient temperatures movement might be associated with odour levels, at intermediate temperatures, with ambient humidity and at higher ambient temperatures with the need to cool buildings. The data on window position, together with other physical measures during the period of observation in the Wallasey School, has been examined to see what quantity is most closely associated with window position. It appears that in the classroom the number of open windows depends mainly upon air temperature, but it also depends markedly on time of day.     

Simulation analysis for the active solar heating system of a passive house

The active solar heating system consists of the following sub-systems: (1) a solar thermal collector area, (2) a water storage tank, (3) a secondary water circuit, (4) a domestic hot water (DHW) preparation system and (5) an air ventilation/heating system. An improved model for the secondary water circuit is proposed and two interconnection schemes for sub-systems (4) and (5) are analyzed. The integrated model was implemented to Pirmasens passive house (Rhineland Palatinate, Germany). Both interconnection schemes show that (almost all) the solar energy collected is not used for space heating but for domestic hot water preparation. The classical water heater operates all over the year and the classical air heater operates mainly during the nights from November to April. The yearly amount of heat required by the DHW preparation system is about 77% of the yearly total heat demand of the passive house and the classical water heater provides about 20% of the yearly heat required by the DHW preparation system. The solar fraction lies between 0.247 in January and 0.930 in August, with a yearly average of 0.597.     

Technoeconomic optimization of a hybrid solar air-heating system

This paper presents a simple techno-economic model for a hybrid solar air-heating system based on water as the storage medium. The configuration of the system consists of a conventional solar air-heater, water tank for thermal storage, a unit which adjusts the higher air temperature (during peak sunshine hours) to the required limit (by mixing fresh air) and an arrangement for providing auxiliary energy if and when required. A thermostatically controlled electric heater is assumed to be the source of auxiliary energy, in the present calculations. In order to evaluate the performance of the system using the developed model numerical calculations have been made corresponding to the climate of Delhi, India. The calculations have been extended to obtain the optimized values of collector area and storage mass which correspond to the minimum value of useful energy. Numerical results show that the cost of useful energy obtained for optimized values of collector area and storage mass is much less than the cost of electrical heating.     

Performance improvement of a solar volumetric reactor with passive thermal management under different solar radiation conditions

To alleviate the effect of solar radiation fluctuation on the solar volumetric reactor, phase change material (PCM) is applied to buffer the temperature vibration and improve the stability of thermochemical reactions. In this work, we analyzed the heat flow and distribution characteristics of the conventional double-walled volumetric reactor filled with PCMs (SVR1). We then proposed a novel solar volumetric reactor design (SVR2) to solve the problems of local high temperature, slow charging-discharging rate, and fluctuating methane conversion in various radiation conditions. The heat and mass transfer model coupled with thermochemical reaction kinetics was established to compare the performance of SVR1 and SVR2 under steady state, heat charging-discharging mode, and actual solar radiation fluctuation, respectively. The results show that compared to SVR1, the maximum temperature of SVR2 decreases by 106.3 K, and the minimum methane conversion rate increases from 77.4% to 93.6% under natural solar radiation fluctuation.     

Analysis of a passive cooled building for the semiarid climate

The quasi-steady-state analysis of a hostel building for semiarid climatic conditions has been presented by incorporating the effectiveness of various cooling approaches in the analysis. The effect of intermittent use of an exhaust chimney, opening of windows and a desert cooler has also been incorporated in the analysis to study its performance. It is observed that there is an appreciable reduction in the room temperature by intermittent use of various cooling approaches.     

The passive solar heated school in Wallasey. VI. Thermal sensation and comfort in the classroom: A year-long study of the subjective and adaptive responses of children

In order to examine relationships between thermal parameters and subjective response, a class of 33 13-year-old children was studied over a period of 63 weeks. Children completed 7 point rating scales of thermal sensation, air movement and dryness and 5 point scales of perceived comfort and wakefulness. Information was collected about clothes worn, windows open and lights in use, as well as data on concurrent thermal variables. In general the classroom was perceived as warm, dry and airless. Children were found to maintain thermal neutrality down to globe temperatures of 17°C by adjusting clothing, windows and lighting. The adaptive responses served to moderate the effect of physical fluctuations on thermal sensation but appeared to be ineffective at globe temperatures over 24°C. A theoretical model of adaptive control of the environment would suggest low correlations between thermal sensation and variables which the children could adjust (clothing, ventilation, heating), and high correlations between these moderator variables and objective room temperatures. The observed set of correlations supports this model. Children seem to be sensitive to differences between mean surface and air temperatures but not to ceiling-floor temperature differences within the ranges studied. There are low correlations between thermal sensation and ‘comfort’. This has implications for energy conservation.     

Some aspects of the use of solar energy in Serbia

This article presents the aspects of solar radiation and the use of solar energy in Serbia. It also considers why Serbia does not use thermal conversion of solar radiation in spite of much greater potential comparing to the countries of the Western and Central Europe, which are leading in the use of solar energy. The low standard of living, low electricity prices, the low level of energy efficiency in all areas of energy use, lack of knowledge, and political decisions are the main causes of insufficient use of renewable energy sources in Serbia.     

Performance optimization and analysis of solar combi-system with carbon dioxide heat pump

In this paper, a solar combi-system which consists of solar collectors and a carbon dioxide heat pump is proposed and investigated through simulation and optimization. Performance analysis and comparison are primarily conducted to show the feasibility and reasonability of using a CO₂ heat pump as an auxiliary heater under local weather conditions. Then, a system model with a test building in TRNSYS is developed for performance optimization. The most influential variables are identified using influence and sensitivity analyzes of single parameters. Subsequently, a multi-parameter optimization using the high-weight parameters is carried out to obtain a final design result. The simulated results of the optimized case show that the average coefficient of performance of the CO₂ heat pump is 2.38, and the solar fraction of the system is 69.0% for the entire heating season. The time when a comfortable temperature level can be achieved in the indoor environment accounts for 81.6% of the entire heating season. Furthermore, the performance characteristics of the proposed system are evaluated in terms of the thermal balance, fraction of the thermal energy saving, feasibility of net zero energy, economic factor, and CO₂ emissions reduction.     

Optimum glazing combination for solar space heating

A study is made for comparing the maximum seasonal energy yield obtainable by solar collectors for space heating application. Different glazing combinations with glass and plastic as glazing materials are considered. The study is made for four different locations. The performance of eight glazing combinations with covers ranging in number from one to three is compared to obtain the optimum combination for each location. The results show that selecting the optimum glazing combination improves the performance significantly. In general, plastic covers give higher yield. The study confirmed that the use of two covers is justified in cold, cloudy climates while a single cover is suitable for temperate climates. In most cases three covers lead to a significant reduction in the yield. Replacing plastic by glass as a top cover for longer life results in a small yield reduction. Some of the other conclusions are that the ratio of average to normal transmittance-absorptance product changes significantly with location and month of the year. However, the seasonal average value of this ratio is almost constant for any number of covers but changes with location.     

Reduction of carbon dioxide emissions by solar water heating systems and passive technologies in social housing

Growing global concern regarding climate change motivates technological studies to minimize environmental impacts. In this context, solar water heating (SWH) systems are notably prominent in Brazil, primarily because of the abundance of solar energy in the country. However, SWH designs have not always been perfectly developed. In most projects, the installation option of the solar system only considers the electric power economy aspects and not the particular characteristics of each climatic zone. Thus, the primary objective of this paper is to assess the potential of carbon dioxide reduction with the use of SWH in comparison with electric showers in social housing in several Brazilian climatic zones. The Brazilian government authorities have created public policies to encourage the use of these technologies primarily among the low-income population. The results of this paper indicate that hot climactic regions demonstrate a low reduction of CO₂ emissions with SWH installations. Thus, solar radiation is not useful for water heating in those regions, but it does lead to a large fraction of household cooling loads, implying a demand for electrical energy for air conditioning or requiring the adoption of passive techniques to maintain indoor temperatures below threshold values.     

Design of a novel passive solar tracker

A novel, low cost solar tracker suitable for use in equatorial regions around the world is presented. The solar tracker is passively activated by aluminium/steel bimetallic strips and controlled by a viscous damper. Computer modelling predicts an increase in efficiency of up to 23% over fixed solar panels. Experimental testing shows excellent agreement with the computer model. In addition, further developments to the design are critically evaluated in terms of complexity and benefit.