Monodraught Ltd

High Wycombe, United Kingdom

Monodraught Ltd

High Wycombe, United Kingdom
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Bako-Biro Z.,Monodraught Ltd | Clements-Croome D.J.,University of Reading | Kochhar N.,University of Reading | Awbi H.B.,University of Reading | Williams M.J.,University of Reading
Building and Environment | Year: 2012

This paper is a development of our earlier work [5,6,11]. The effects of classroom ventilation on pupils' performance were investigated in 8 primary schools in England. In each school the concentrations of carbon dioxide and other parameters were monitored for three weeks in two selected classrooms. In 16 classrooms interventions were made to improve the ventilation rate and maintain the temperature within an acceptable range using a purpose-built portable mechanical ventilation system. As a result of the interventions the provision of outdoor air to the classrooms was improved from the prevailing levels of about 1 l/s per person to about 8 l/s per person.The pupils and teachers in the classrooms studied were usually exposed to unacceptably poor air quality conditions, with CO 2 concentrations of up to 5000 ppm, much higher than the average recommended levels of 1500 ppm and the preferred level of 1000 ppm.The results of computerized performance tasks performed by more than 200 pupils showed significantly faster and more accurate responses for Choice Reaction (by 2.2%), Colour Word Vigilance (by 2.7%), Picture Memory (by 8%) and Word Recognition (by 15%) at the higher ventilation rates compared with the low ventilation conditions.The present investigation provides strong evidence that low ventilation rates in classrooms significantly reduce pupils' attention and vigilance, and negatively affect memory and concentration. The physical environment therefore affects teaching and learning. © 2011 Elsevier Ltd.

Jones B.,Monodraught Ltd
Building Engineer | Year: 2010

A comparison between natural ventilation and air conditioning in UK environmental conditions is presented. The main differences between the operation of mechanical and natural ventilation are the characteristics and variability of the driving forces, which in naturally ventilated buildings are buoyancy and wind driven. It is easier to supply a controlled ventilation rate using a mechanical system than a natural ventilation system. and a mechanical air conditioning system can be used to control the cleanliness, temperature, and humidity of the supplied and recycled air. When compared against buildings that are naturally ventilated, occupants often perceive the indoor environment to be better in the naturally ventilated buildings. The quality of the indoor environment is judged by the indoor temperature and the thermal comfort of occupants, which is defined as the condition of mind that expresses satisfaction with the thermal environment.

Khan N.,University of Nottingham | Khan N.,Monodraught Ltd | Su Y.,University of Nottingham | Hopper N.,Monodraught Ltd | Riffat S.,University of Nottingham
International Journal of Ventilation | Year: 2011

This paper presents a simplified modelling process by using experimental results to form empirical relationships for a particular novel windcatcher natural ventilation and cooling system developed by Monodraught in the United Kingdom. In particular, the behaviour of this system, which is integrated with a DC fan and PV panel without a backup battery, is modelled for the whole year. The impact of natural and night time ventilation with thermal mass on cooling and mitigating overheating is investigated. Pressure losses from openings, louvres, ducts, dampers etc are accounted for and simplified in the modelling process. Dynamic thermal models are used to simulate natural ventilation, evaporative cooling and PV powered fans.

Su Y.,University of Nottingham | Yu X.,University of Nottingham | Zhang L.,University of Nottingham | Karagianni M.,University of Nottingham | Khan N.,Monodraught Ltd
Energy Procedia | Year: 2012

Daylighting can offer the benefit of view comfort and saving energy, so it has become more and more important in acting as the principal source of lighting in buildings. This study attempts to evaluate energy saving potential of the well-known MonodraughtTM sunpipes installed in a supermarket in the UK. A lighting analysis software package RELUX is used as the simulation tool to calculate daylight factor and illuminance distribution within the supermarket. The energy saving potential of using MonodraughtTM sunpipes in the supermarket is assessed using RELUX Energy. The simulation results indicate that a considerable saving in the lighting-related energy consumption could be achieved through use of MonodraughtTM sunpipes accompanied by an artificial lighting control. © 2011 Published by Elsevier Ltd.

Su Y.,University of Nottingham | Khan N.,University of Nottingham | Khan N.,Monodraught Ltd. | Riffat S.B.,University of Nottingham | Gareth O.,University of Nottingham
Energy and Buildings | Year: 2012

This paper presents comparative monitoring of various sized commercial lightpipes at a purposely built test shed with a pitched roof. The purpose of monitoring is to simultaneously compare the performance of lightpipes of different geometries and also to provide data for establishing a formula for performance prediction. The photometric integrating box, which BRE (Building Research Establishment) has adopted as an approximation to the photometric integrating sphere, is employed to determine the lumen output of the lightpipes under real sky condition. This study presents monitoring of four sized lightpipes: straight Φ530 mm, elbowed Φ530 mm (with a tilted entrance), elbowed Φ450 mm and elbowed Φ230 mm. A mathematical model is proposed to correlate the measured lumen output, horizontal global illuminance, the diameter and length of the lightpipe, the specular reflectance, solar altitude and azimuth, and orientation of elbow if an elbowed lightpipe is tested. The coefficients in the formula are determined by regression of the monitoring data. The formula is then used to predict the lumen output of a lightpipe from the measured global illuminance for the given geometry and time. The agreement between the measured and predicted lumen output is generally satisfactory. The formula may be a useful design tool as it can predict the lumen output of a lightpipe from the global illuminance value such as those given in EnergyPlus weather data. © 2012 Elsevier B.V. All rights reserved.

Monodraught Ltd | Date: 2010-12-08

A reflector arrangement 10 for use on the upper end of a light pipe 12. The arrangement 10 includes a bell shape glassed dome 20 in which is provided a main reflector 26 in the form of a convex frusto conical part which diverges up wardly, with a side reflector 32 on each side of the main reflector 26. Each reflector 32 has a substantially part cylindrical form decreasing in width upwardly to an apex 34 adjacent to upper corners of the main reflector 26.

Monodraught Ltd | Date: 2011-03-09

A ventilation arrangement 10 for ventilating the interior 12 of a building. The arrangement 10 includes a duct 18 extending to above the roof 14 of the building. The duct 18 is square in cross section and is divided into four quadrants by internal vertical divider plates. A louvre arrangement 22 is provided on each side of the upper part of the duct 18 to receive air into the building on a windward side of the duct 18, and to expel air from a leeward side of the duct 18. A closure arrangement 26 is provided for selectively partially or wholly closing the louvre arrangements 22, for instance in the event of bad weather.

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