Reference: AIVC on Windbreaks and Shelterbelts

http://www.aivc.org/publications/literature_lists/litlist12.html

#NO 2892 Dampening of wind pressures and forced convection in mineral fibre wall structures.

AUTHOR Kokko E, Kavonen M L, Ojanen T, Virtanen M

BIBINF Technical Research Centre of Finland, Research Report (1987) 5p, 3 figs, 2 refs. #DATE 00:00:1987 in English

ABSTRACT Damping of wind effects and forced convection in ventilated small house wall structures with light weight continuous mineral fibre insulations have been studied theoretically and experimentally. Pressure conditions in different ventilating air spaces are computed with a static-multicell-airflow-model called MOVECOMP. Thermal effects of steady state forced convection in insulations are simulated with a computer program CCC2D (Coupled head convection and conduction in two dimensions). Both pressure conditions and thermal effects have been measured in a test house envelope. Structural variables were the construction of ventilating air space, permeance of windbreak and frame construction in thermal insulation layer.

KEYWORDS wind pressure, wall, wind effect, insulation, air flow, convection

#NO 3065 Energy saving through landscape planning. 1. The background.

AUTHOR Dodd J S

BIBINF UK, PSA, 1988. #DATE 00:00:1988 in English

ABSTRACT There are many functional values in landscape design. Two of the most important and traditional are the efficient provision of shelter against wind chill, and shade to soften glare that often occurs with large areas of south facing windows. Both relate to the improvement of comfort by managing energy resources in a more efficient way. Not enough has been done in Britain to utilise the well proven old tradition of shelter planting to meet modern needs. The concept led to the commissioning of six consultants to examine specific aspects of energy conservation through landscape measures in relation to both new and older housing. It is certain that not only would the exposed areas of the UK benefit from shelter belt planting but the northerly edges of most cities and towns. The potential varies widely in scale, from the tractsof ex urban land to exposed and isolated building groups and new farm buildings.

KEYWORDS energy conservation, shelter belt, windbreak

#NO 3067 Energy saving through landscape planning. 3. The contribution of shelter planting.

AUTHOR Finbow M

BIBINF UK, PSA, 1988 #DATE 00:00:1988 in English

ABSTRACT The aim of the project was to provide preliminary quantitive estimates of the effect on energy use of planting shelter belts, taking into account any losses from reduced solar gain, in relation to a limited number of housing estate layouts already studied as part of the ETSU Passive Solar Programme. Work was concentrated on 1. measurement of the extra heating demand from perimeter shelter belts on three housing estates. 2. General studies of increased heating demand in relation to a variety of house/shelter belt configuration.

KEYWORDS energy saving, shelter belt, heating needs

#NO 3070 Energy saving through landscape planning. 6. A study of the urban edge.

AUTHOR Collins M, Barnsley M

BIBINF UK, PSA, 1988 #DATE 00:00:1988 in English

ABSTRACT Interest has recently been generated in forestry as a farm crop and in the necessity for a more relaxed attitude to housebuilding in the countyside. Alternative land use scenarios highlight the scope which now exists to secure "climatically sensitive" site layouts which offer protection from adverse weather conditions and yet still derive maximum benefit from fine weather. Three case studies have provided further information about edge characteristics including building types, land use, extent of planted shelter and the definition and revision of green belt boundaries.

KEYWORDS energy saving, shelterbelt

#NO 3187 Ventilation loss and passive solar heat gain in a Swedish housing estate: the influence of local climate, orientation and windbreaks.

AUTHOR Wiren B, O'Mara A H

BIBINF Sweden, National Swedish Institute for Building Research, TN:8, September 1987, 44pp. #DATE 00:09:1987 in English

ABSTRACT The main purpose of the work presented in this report is to illustrate the influence of climate conditions and wind shelter on ventilation losses due to the natural ventilation of a housing estate.

KEYWORDS wind tunnel, model, shelterbelt, heat loss

#NO 3661 Light attenuation by trees.

AUTHOR McKennan G T

BIBINF UK, For presentaion at the BRE Seminar: "Microclimate and the Environmental Performance of Buildings: April 1988, 18 pp, 8 figs, 1 tab, 9 refs. #DATE 00:04:1988 in English

ABSTRACT The use of daylight to offset the consumption of electricity for lighting within buildings has become a recognised building energy management concept. Trees by their very nature attenuate light from the sky and are therefore potentially in conflict with this natural lighting of building interiors. Thecustomary means of expressing interior daylighting is by the "daylight factor", the internal illuminance expressed as a percentage of illuminance occurring simultaneously on a horizontal surface outdoors exposed to the whole overcast sky. The daylight factor at a point in a room depends largely on the area of sky that can be seen through the window from that point. Both treegeometry and crown attenuation characteristics are therefore important in predicting the reduction in daylight in an interior due to the presence of trees. This would not present a problem for the designer if trees were simply obstructional features of the landscape. However, they have many positive roles to play around buildings. People prefer view of trees, grass and open space to views of adjacent buildings. Trees have positive associations within our culture and language. They can attenuate noise and can act to improve the energy efficiency of buildings by performing as wind breaks and by providing solar shade in summer. Careful consideration of their light attenuation characteristics is therefore necessary before we judge them as desirable or not within our designs.

KEYWORDS trees, windbreak, shade

#NO 3663 The effect of tree planting on energy use in passive solar heating.

AUTHOR Finbow M

BIBINF UK, BRE Seminar "Microclimate and the environmental performance of buildings", BRE Garston, 19th April 1988, 9pp, 3 figs. #DATE 00:04:1989 in English

ABSTRACT The aim of the project was to provide preliminary quantitative estimates of the effect on energy use of planting shelter belts, taking into account any losses from reduced solar gain, in relation to a limited number of housing estate layouts already studied as part of the ETSU Passive Solar Programme. The work formed part of a series of studies on energy saving through site planning sponsored by the Property Services Agency in association with the Building Research Establishment.

KEYWORDS trees, passive solar heating, shelter belt

#NO 3665 The climatic exposure of urban edges and the prospects for initiatives through development control.

AUTHOR Collins M P

BIBINF UK, BRE Seminar "Microclimate and the environmental performance of buildings", BRE Garston, 19th April 1988, 19pp, 9 figs, 10 refs. #DATE 00:04:1988 in English

ABSTRACT It is generally agreed that the microclimatic effects of shelter are exceedingly complex, reflecting the interaction of topography, wind conditions, humidity, soil moisture and temperature, air temperature, radiation balance, and diurnal and seasonal climatic changes. However, the new suburban housing estates which often constitute the urban edge are subjected to higher wind levels and wind chill factors than are encountered further in, and would clearly benefit if additional shelter were provided. This shelter could take the form of extensive tree planting between the houses, the use of shelter belts and an increase in the "roughness" of the landscape beyond the residential development. There is sufficient empirical evidence to suggest that shelter belts can also lead to energy savings in the region of 5 to 10%. The relationships between urban costs, and between urban structure, density and climate are also receiving further attention.

KEYWORDS shelter belt, energy saving

#NO 3736 Winter performance of different air inlets in a warm naturally ventilated swine barn.

AUTHOR Choiniere Y, Blais F, Munroe J A, Leclerc J-M

BIBINF Canada, Canadian Agricultural Engineering, No.31, 1989, pp51-54, 5 figs, 12 refs. #DATE 00:00:1989 in English

ABSTRACT Air flow patterns and temperature distributions were determined under winter conditions in eastern Ontario in a warm naturally ventilation swine barn fitted with different types of sidewall openings. The building was originally built with rotating panels in the side walls. Material was then added in various configurations to these wall openings to simulate the vertical panel system, as well as windbreak panels. The vertical panel, as compared to the rotating doors, resulted in less temperature fluctuation in the animal area for both leeward and windward ventilation. The added windbreak improved performance in minimizing temperature fluctuations.

KEYWORDS natural ventilation, animal house

#NO 3737 A wind tunnel study of airflow patterns in a naturally ventilated building.

AUTHOR Choiniere Y, Blais F, Munroe J A

BIBINF Canada, Canadian Agricultural Engineering, No.30, 1988, pp293-297, 8 figs, 2 tabs, 15 refs. #DATE 00:00:1988 in English

ABSTRACT A simple wind tunnel was built to develop an airflow pattern visualization technique using a geometric scale model of a building. The tunnel was used to evaluate the performance of three different air inlet configurations for summer ventilation in a naturally ventilated building. These air inlet configurations were the following sidewall panels rotated about a horizontal axis to 15 deg, 30 deg, or 60 deg from vertical, or vertical panels (simulating the common plastic curtain system) of four different heights. As well, the effect of small windbreak panels outside the sidewall opening was investigated. Wind speeds of 0.42, 0.64 and 2.78 m/s were evaluated. Results showed similar airflow patterns with either the rotating or vertical panels. The windbreak panels created some extra turbulence, especially with the larger openings, which improved mixing. A threshold Reynolds number of 5400 was established for a scale model of a naturally ventilated barn shown in Canada Plan Service plan M-3433.

KEYWORDS wind tunnel, air flow, natural ventilation

#NO 4708 The wind shielding and shading effects of trees on residential heating and cooling requirements.

AUTHOR Huang Y J, Akbari H, Taha H

BIBINF USA, ASHRAE Transactions, Vol 96, Part 1, pp 1403-1411, 4 figs, 8 tabs, refs. #DATE 00:00:1990 in English

ABSTRACT

KEYWORDS shelter belt, heating needs, cooling

#NO 5025 Experimental study on wind pressure and air flow around a dwelling house with arboreal hedges.

AUTHOR Tsutsumi J-I, Katayama T, Hayashi T, Zhang Q, Xue H

BIBINF Recent Advances in Wind Engineering, proceedings of the second Asia-Pacific symposium on Wind Engineering, Beijing, China, June 26-29 1989, Volume 1, edited by T F Sun, pp 568-575, 9 figs, 1 tab, 11 refs. #DATE 00:06:1989 in English

ABSTRACT Effects of arboreal hedges on wind pressure on the wall of a single unit dwelling house and on an air flow around the house are described in this paper. A model house with hedges which are lines of real trees is used for field experiments. A similar model reduced to a scale of 1/15 of the field model is used for wind tunnel tests. Several layout types of hedges are examined, some are obstacles to the wind and the others are furtherance of the wind pressure. The results of the wind tunnel tests are in accordance with those of the field experiments in some layout types.

KEYWORDS wind pressure, air flow, shelter belt

#NO 5026 A study on the influence of trees on ventilation of dwellings. Part 1 Experiments on pressure difference between the windward and leeward of a building.

AUTHOR Xue H, et al

BIBINF Japan, Trans AIJ (?), [1989], pp 851-852. #DATE 00:00:1989 in Japanese

ABSTRACT

KEYWORDS shelter belt, pressure difference

#NO 5748 Climate and site development Part 3: Improving microclimate through design.

AUTHOR BRE

BIBINF UK, Building Research Establishment, Digest 350, Part 3, April 1990, 12pp, 25 figs, 25 refs. #DATE 00:04:1990 in English

ABSTRACT This Digest describes how microclimate is affected by the geography and topography of a site and its surroundings, and how it can be further influenced by the arrangement of buildings and landscape features. It reviews techniques for planning a climatically sensitive site layout, giving maximum benefit from fine weather and some protection from adverse weather. This can benefit building performance by reducing energy consumption and improving durability, and can make the spaces around buildings more attractive and useful by providing better conditions for outdoor activities. This Digest is published in three parts. The other two parts are: Part 1: General climate of the UK Part 2: Influence of microclimate Part 3: Improving microclimate through design. The numbering of references, tables and illustrations continues through the three parts: references and further reading are listed in Part 3.

KEYWORDS shelter belt, shade, wind pressure

#NO 5885 Climate and site development. Part 1: General climate of the UK.

AUTHOR BRE

BIBINF UK, Building Research Establishment, Digest 350, February 1990, 4pp 7 figs. #DATE 00:02:1990 in English

ABSTRACT This Digest describes how microclimate is affected by the geography and topography of a site and its surroundings, and how it can be further influenced by the arrangement of buildings and landscape features. It reviews techniques for planning a climatically sensitive site layout, giving maximum benefit from fine weather and some protection from adverse weather. This can benefit building performance by reducing energy consumption and improving durability, and can make the spaces around buildings more attractive and useful by providing better conditions for outdoor activities.

KEYWORDS climate, shelter belt, shading

#NO 5886 Climate and site development. Part 2: Influence of microclimate.

AUTHOR BRE

BIBINF UK, Building Research Establishment, Digest 350, March 1990, 7pp, 10 figs, 4 tabs. #DATE 00:03:1990 in English

ABSTRACT This Digest describes how microclimate is affected by the geography and topography of a site and its surroundings, and how it can be further influenced by the arrangement of buildings and landscape features. It reviews techniques for planning a climatically sensitive site layout, giving maximum benefit from fine weather and some protection from adverse weather. This can benefit building performance by reducing energy consumption and improving durability, and can make the spaces around buildings more attractive and useful by providing better conditions for outdoor activities.

KEYWORDS climate, shelter belt, shading, energy conservation

#NO 6134 Courtenay place wind environment.

AUTHOR Donn M, Davies K

BIBINF New Zealand, Victoria University of Wellington, School of Architecture, CRP 51, June 1989, 17pp. #DATE 00:06:1989 in English

ABSTRACT The research is based on a widely used wind engineering methodology for qualitative examination of urban wind environments using a wind tunnel. The methodology has been adapted by the School of Architecture for use by building designers to establish compliance with the Wellington City Wind Ordinance. The results show that a 12 metre high wind gate across the Western entrance to Courtenay Place would indeed have a beneficial effect on the wind conditions in the triangular area of the street between the Saatchi building, the St James and the gentlemen's toilets.

KEYWORDS wind pressure, laboratory, wind tunnel, shelter belt

#NO 6287 Reduction of cooling loads and CO2 emissions through the use of vegetation in Italian urban areas.

AUTHOR Barbera G, Pecorella G, Silvestrini G

BIBINF Kluwer Academic Publishers, 1991, proceedings "PLEA 91: Architecture and Urban Space", Ninth International PLEA Conference, Seville, Spain, September 24-27 1991, pp 41-46. #DATE 00:00:1991 in English

ABSTRACT With the rapid diffusion of air conditioning in Italy, different options should be considered in order to reduce the impact of this application on the electric system. In this paper the effect on air temperature reduction due to an increase of green areas in the context of two Italian towns has been examined. The savings on cooling load of a typical office module could decrease by 8-11% with an increase of the vegetated area of 10%. In terms of carbon dioxide reductions this contribution is almost ten times higher than the amount stored through photosynthesis.

KEYWORDS carbon dioxide, shelter belt, cooling

#NO 6372 Wide naturally ventilated breeding-gestation units and new ridge air inlet design for 26 m wide farrowing-nursery units for a 700 sow complex.

AUTHOR Choiniere Y, Moore C, Gingras G, Munroe J A

BIBINF Canada, Canadian Society of Agricultural Engineering, paper presented at the Agricultural Inst of Canada Annual Conference, July 5-9, 1992, Brandon, Manitoba, 17pp, 15 figs, refs. #DATE 00: 07:1992 in English

ABSTRACT This new 700 sow complex incorporates two major innovative technologies. The 19 m x 73 m breeding-gestation unit is naturally ventilated using intermittent chimneys and continuous vertical sidewall panels complete with windbreaks. A new digital, automatic control system is used to activate the sidewall openings. The farrowing and nursery units are contained in a 26 m x 64 m building. A newly developed ventilation system draws air through a wide continuous ridge opening into a central attic duct. Lateral distribution ducts in the attic then feed each room independently. This paper describes advantages of this ventilation system, as well as presents laboratory results relating air flow characteristics to ridge design.

KEYWORDS natural ventilation, animal house, air inlets, ridge vent

#NO 6376 Automatically controlled natural ventilation in a modified environment dairy barn.

AUTHOR Munroe J A, Choiniere Y, McKnight D, Tremblay A S, Brunet L

BIBINF Canada, Canadian Society of Agricultural Engineering, paper presented at the Agricultural Inst of Canada Annual Conference, July 5-9, 1992, Brandon, Manitoba, 13pp, 5 figs, 1 tab, refs. #DATE 00:07:1992 in English

ABSTRACT Traditionally, modified environment barns have been lightly insulated and depended upon permanent or manually operated openings in the walls and ridge for ventilation. In 1991, a free-stall heifer barn at Kemptville College was renovated to incorporate a natural ventilation system consisting of a series of chimneys and automatically controlled sidewall curtains complete with windbreaks. The purpose of this study was to determine the frequency and extent of sidewall curtain movement, monitor indoor environment, and determine the minimum sidewall and ridge openings required to ensure adequate winter ventilation. Preliminary results obtained during the winter of 91/92 indicate that the curtains moved almost every day including when the outside temperature was below -20 Deg C. Excellent temperature regulation was observed. High relative humidity was noted (>90%) however, when accompanied with indoor temperatures of 0-5 Deg C, indoor environment appeared to be excellent.

KEYWORDS natural ventilation, animal house, openings, cold climate

#NO 6827 Mitigation of urban heat islands; materials, utility programs, updates.

AUTHOR Rosenfield A H, Akbari H, Bretz S, Sailor D, Taha H

BIBINF Submitted to Journal of Energy Efficiency, Vol.1, No.1, 1993, 20pp, 8figs, refs. #DATE 00:00:1993 in English

ABSTRACT Using white surfaces to increase the albedo of a city may be a lucrative way to conserve energy and reduce pollution. Utilities could promote high-albedo surfaces to earn profits and reduce the demand for peak power. Suggested programs include paint labeling, marketing, and incentives for using light-colored materials for buildings and roads. We present three recent measurements: the air-conditioning savings on a test house in Sacramento, on two houses in Florida, and some air temperature measurements at White Sands, New Mexico. In addition, we discuss the results of some meteorological simulations performed for Los Angeles, CA, that validate the measured data from White Sands.

KEYWORDS cooling, shade, shelter belt

#NO 6828 The imprint of trees and white surfaces on residential heating and cooling energy use in four Canadian cities.

AUTHOR Akbari H, Taha H

BIBINF UK, Energy, Vol.17, No.2, 1992, pp.141-149, 6tabs, 8refs #DATE 00:00:1992 in English

ABSTRACT We have investigated the potential of using vegetation and high-albedo materials in Toronto, Edmonton, Montreal and Vancouver, Canada, to modify the urban microclimate, thereby saving residential heating and cooling energy use. Parametric computer simulations of microclimates and energy performance of prototypical houses were our primary analysis tools. The building prototypes included a detached one-story and a detached two-story single family house, as well as a row house. The simulations indicated that by increasing the vegetative cover of the neighborhood by 30% (corresponding to about three trees per house) and increasing the albedo of the houses by 20% (from moderate-dark to medium-light color), the heating energy in Toronto can be reduced by about 10% in urban houses and 20% in rural houses, whereas cooling energy can be reduced by 40 and 30%, respectively. The annual savings in heating and cooling costs for different houses ranged from $30 to $180 in urban areas and from $60 to $400 in rural zones. In urban houses of Edmonton, Montreal, and Vancouver, savings in heating energy use were about 10%. Cooling energy can be totally offset in Edmonton and Vancouver, and average savings of 35% can be achieved in Montreal.

KEYWORDS cooling, shelter belt, energy saving, simulation

#NO 7380 The effects of wind protective urban arrangements on the ventilation energy consumption.

AUTHOR Visser G, Jong T M de.

BIBINF Journal of Wind Engineering and Industrial Aerodynamics, Nos 41-44, 1992, pp 2587-2597, 8 figs, 1 tab, 6 refs. #DATE 00:00:1992 in English

ABSTRACT A model has been set up for estimating the reduction in ventilation energy consumption through the use of wind protective measures at different urban levels. The effects of planning and urban wind protective measures on ventilation energy consumption appear to be a function of the urban level considered. The efficiency of such measures is partly offset by occupants' behaviour. Starting from a pessimistic assumption with respect to occupants' behaviour, in the Dutch situation with a temperate climate ventilation energy consumption can be reduced by roughly 1 to 15%. However, in colder climates and with a more optimistic assumption of occupants' behaviour the efficiencies may well be higher.

KEYWORDS shelter belt, wind effects, energy consumption, occupant behaviour.

#NO 7748 Wind shielding effects of trees on low buildings.

AUTHOR Stathopoulos T, Chiovitti D, Dodaro L

BIBINF UK, Building and Environment, Vol.29, No.2, 1994, pp141-150, 16 figs, 2 tabs, 22 refs #DATE 00:00:1994 in English

ABSTRACT Tree windbreaks form an important mechanism for reducing wind-induced air infiltration in buildings. However, they also affect wind loading determined mainly by wind standards and building codes of practice for a homogeneous terrain environment. A wind tunnel study was carried out to examine the effects of various tree configurations on wind-induced air infiltration and structural loading of low-rise buildings. The results showed that a single row, high density windbreak reduced air infiltration by about 60% when planted approximately four tree heights away from the building. The correspondence to a 15% reduction in energy costs. The efficiency of windbreaks depends on the direction of dominant winds. Results have also shown that pressure coefficients are generally lower than those specified by wind standards and codes of practice with the exception of side wall regions and certain roof areas.

KEYWORDS Windbreak, trees, low rise building, wind effects

#NO 8509 Shade trees as a demand-side resource.

AUTHOR McPherson G, Simpson J R.

BIBINF USA, Home Energy, March/April 1995, pp 11-17, 4 figs, 7 refs.

ABSTRACT Describes how several utilities in the USA have embraced trees as a solar-powered demand-side management resource, and explores what we know about the effects of shade trees on building energy performance.

KEYWORDS Shade, shelter-belt, cooling, energy efficiency.

#NO 10494 Planted circumstances and wind break techniques in the Isles of the East China sea.

Morita D, Tokashiki T

Japan, PLEA 1997 Kushiro Secretariat, proceedings of a conference held 8-10 January 1997, Kushiro, Japan, Volume 2, pp 85-88, 4 figs, 5 refs.

In this paper the authors describe in detail the planted circumstances with wind-break effects, developed in the isles of Tonaki and Aguni, tens of kilometers off the mainland of Okinawa in the East China Sea; both these isles are abundant in Fukugi, an evergreen, tall and sturdy tree of tropic origin; and the time-honored Fukugi groves have played an all-important role in protecting the people and their properties against the year-round strong winds, and casual but frequent typhoons. The Fukugi trees have been planted around each of house premises on three or four sides, arranged in different ways; in Tonaki the village street crossings were so arranged as to be out of alignment in one direction, with a distinct intention of making such irregular arrangement resist any possible wind acceleration. In Tonaki, almost all houses would be built on sunken grounds, besides the Fukugi windbreaks, to avoid being hit direct by the fierce wind, while in Aguni no such artificial house-sites are found. These devices are fairly efficient, from the bioclimatic point of view, because they are to mitigate the cooling-off effect on the entire house envelopes in the windy season of Okinawa area.

windbreak, wind effects

#NO 11059 Bioclimatic house for Tenerife - "Ventilation wall".

Goluboff M, Rodriguez E, Castelanos J L, Baalina A, Santaballa J A, et al

USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 3, pp 363-368.

The moonlike landscape and the heat of the site suggested us the creation of an oasis open to the northern cool breeze from the Northeast and to close our house toward the sun and torrid winds from the South. That is how the idea of a curved wall embracing the house and a patio was born, recalling ancient stone protections for vineyards. We transformed the stone wall into a complex element, forming a natural air-conditioning chamber which works as a breeze catcher and due to the design of it's different elements, regulates the interior climate of the house.

dry climate, wind effects, shelter belt

#NO 11593 Air conditioning and noise control using vegetation.

Costa P R

Workplace Comfort Forum, London, March 1995, 11 pp, 4 figs, 3 tabs, 53 refs.

The constructive uses of vegetation in building engineering services are acoustic quieting, air molecular and particulate filtration, water filtration and chemical polishing, shading from solar gain, cooling and humidification. A water conservation regime should form part of the integrated solution.

shelter belt, shading

#NO 11831 Air flow simulations in a place dedicated to meditation. The Cistercian Cloister.

de la Foye A, Joanne P

UK, James & James Ltd, 1988, proceedings of "Environmentally friendly cities", PLEA 98 (Passive and Low Energy Architecture) conference, held Lisbon, Portugal, June 1998, pp 191-194, 9 figs, 5 refs.

Confronting the high density of town planning, architects and town planners are led to design small outdoor places which are inserted into the city but offer specified properties: serenity, calmness, unusual surrounding ... Within the framework of the CERMA laboratory, we are looking for reference architectural examples likely to meet such needs and transposable into a contemporary architectural project.

A research work in progress is dealing with Cistercian abbey cloisters, archetypes of a space sheltered from outer nuisances which was originally dedicated to meditation and self-communion. Our work consists of checking whether the tranquillity of this place lies on physical datas which are easily controllable by the designer.

In regard to our research, Cistercian cloisters present the following interests:

* it is a typical architectural figure from which several developments can derive: patios, squares, ...

* it is present in the whole of European countries and therefore has to suit to very different climatic and topographic compulsions;

* it was designed in a rational way and found upon a pattern which is easy to modelise.

A preliminary work has already been carried out which was focused on daylighting, acoustics, and air flow. The study of daylighting was based upon the modelisation of a sample of Cistercian abbey and its simulation with the software designed by the CERMA: Solene. The study of the soundscape rested on in situ measures made in the cloister of the Cistercian abbey of Noirlac (France) and theoretical estimations. We also undertook a preliminary approach of the cloister capacity for sheltering from the wind by setting up a 2D simulation with the finite element CFD code N3S. Our presentation will show this last point which supplied us quite interesting results and now form the subject of further research work.

air flow, simulation, courtyard, daylighting, acoustics, shelter belt

#NO 12017 Climatic design of a new housing area.

Kristensen P E

in: UK, James and James, 1998, European directory of sustainable and energy efficient building 1998. Components, services, materials, pp 29-33, 10 figs, 6 refs.

Describes a project initiated in Frederikshavn in northern Jutland, Denmark, for the climatic design of a new housing area. The site is particularly exposed to strong winds all the year round and one of the major tasks was to design the overall building site and the buildings so that major improvements in the exterior wind environment were achieved. Furthermore, the design brief called for an overall climatic design, where low-energy solutions were combined with consideration of the exterior environment near the buildings. The main results from an analysis of improvement of the comfort for people outdoors were that out of 900 sunshine hours during summertime it is comfortable to remain outside on terraces and the like for 70 hours if there are no shelter belts and 170 hours if there are shelter belts present. Comfortable strolling outside is possible for approximately 370 hours if without shelter belts, rising to approximately 520 hours, out of a total of 900 sunshine hours, if there are shelter belts. Model testing was carried out in a wind tunnel and provided a good basis for developing a good building and site layout, and thus a significant improvement of the local wind environment in the pilot project was achieved. This was confirmed both by wind monitoring in the area, and by the subjective evaluation of the users.

residential building, outdoor air, wind effects, wind break

#NO 12118 Jet momentum criteria for inlet control to reduce wind effects on the air distribution in a side-wall-inlet ventilation system.

Zhang G, Lee S-H

Sweden, Stockholm, KTH Building Services Engineering, 1998, proceedings of Roomvent 98: 6th International Conference on Air Distribution in Rooms, held June 14-17 1998 in Stockholm, Sweden, edited by Elisabeth Mundt and Tor-Goran Malmstrom, Volume 2, pp 525-532, 7 figs, 12 refs.

A problem in a livestock building ventilated in the system with wall inlet at two sides is wind effects to the indoor air flow patterns. The in-proper inlet jet penetration profiles may cause draught at occupied zone and unnecessary stress of animals. The wind effects on such a break can be reduced by applying windbreak to the inlets from design point of view. However, a remain issue is if the effect could be reduced by regulating inlet opening and how to perform the control operation.

The hypothesis of this study is that the unbalance of the incoming air flows from the two side wall, which caused by wind effects, can be overcome by adjusting the inlet openings to maintain the balance of the jet momentum of the both incoming air jets. If that is true, inlet jet momentum criteria should be able to applied in a control system to maintain the similar inlet jets from both side walls.

A 1/10 scale model of a livestock building with both-side wall inlet was used in the investigation in laboratory conditions. In the experiments, the model was placed at a wind board with simulated wind speed of 0-3.5m/s across the model. Different ventilation rates, inlet openings and operating pressures were applied. The experimental results great supported the above hypothesis. It is concluded that if the jet momentum ratio is maintained to unity under the wind condition, the jet penetration depths from two sides will be balanced. The jet momentum criteria can be applied to control side wall inlets to reduce wind effect on the indoor air distribution.