#NO 9211 Remodelling kitchens: a smorgasbord of energy savings.
AUTHOR Sullivan B
BIBINF USA, Home Energy, September/October 1995, pp 11-16.
ABSTRACT Since the kitchen is often the busiest room in the house and the social hub of household life, and the room most likely to be repeatedly remodelled over the house s lifetime, a remodelling can be an opportunity to introduce many new energy saving features or to make as many energy mistakes. The kitchen represents a concentration of household energy use - between 20% and 40% of a home s consumption. The article considers the various ways in which a kitchen s energy efficiency can be improved, considering appliances, lighting, windows and skylights, ventilation and insulation and air sealing.
KEYWORDS kitchen, energy saving, retrofitting
#NO 9220 Kitchen ventilation.
AUTHOR Kelso R M, Rousseau C
BIBINF USA, Ashrae Journal, September 1995, pp 32-36, 2 tabs.
ABSTRACT Surveys a new Ashrae handbook chapter which deals with kitchen ventilation. Kitchen ventilation centers around the capture and removal of airborne contaminants that are generated during the cooking process. These contaminants are poorly characterized at the time of writing, but research is underway to further study them. They include gases, vapors, heat and particulates such as liquid grease droplets. Heat from cooking causes a rising column or air called a plume which contains most of the contaminants. A hood is used to receive and contain the plume and its contaminants and direct them into a duct to be filtered and removed, of sometimes recirculated. The design and construction of hoods are strongly controlled by fire and building codes and sometimes other local codes. The chapter categorizes hoods into Type I hoods for handling grease-laden air and Type II for handling steam, heat and odours. Type I hoods may be designed and constructed to meet code requirements, or they may be listed by a recognized testing agency. Listed hoods may not meet the standards code requirements - for instance they may be operated at a lower airflow rate - but are usually accepted by local code authorities. Goes on to describe in detail type I and II hoods.
KEYWORDS kitchen, ventilation system, pollutant
#NO 9273 Design of kitchen extract ventilation and grease elimination for commercial kitchens. Diseno de los sistemas de extraccion de humos y eliminacion de grasas en las cocinas industriales y colectivas.
AUTHOR Keyzan E H
BIBINF Spain, Instal. Tec. Con., April 1995, No 68, pp 45-56, 7 figs, 7 tabs, in Spanish.
ABSTRACT Sets out a step by step approach to the design of ventilation extract systems for industrial and commercial kitchens where a high level of grease can be expected. The procedures include specifically ductwork and hood design, fan and filter selection. Supplies takes relating to air flow and pressure loss of the system components plus illustrations of practical solutions. Also describes and illustrates modular applications of kitchen extract systems.
KEYWORDS kitchen, extract ventilation, commercial building
#NO 9301 Developments in air admissions. Les evolutions de la fonction admission d air: les propositions ALDES.
AUTHOR Nouvel J F
BIBINF France, Agence de l Environnement et de la Maitrise de l Energie, (ADEME) 1995, proceedings of Ventilation des Batiments: Etat des lieux - Prospective , held Sophia Antipolis, 25-26 October 1995, organised by GEVRA, Groupe d Etude sur la Ventilation et le Renouvellement d Air, pp 118-124.
ABSTRACT The entry of air into residences will have to evolve significantly in the next few years. The first of these evolutions are linked to the regulatory environment (New acoustic regulations and standards of design and dimension). It is estimated that studies conducted on the perception of ventilation by users will encourage new responses to the air entry question. The article distinguishes between visible and invisible ventilation needs. Invisible needs must be treated without the knowledge of the occupant. In contrast, the occupant can have a role in regulating the visible ventilation, e.g. odours and kitchen fumes etc.
KEYWORDS standard, noise pollution, ventilation needs
#NO 9306 Operation of a mechanically assisted natural ventilation system. Mise au point d un systeme de ventilation naturelle assistee mecaniquement.
AUTHOR Amphoux A, Villenave J G
BIBINF France, Agence de l Environnement et de la Maitrise de l Energie, (ADEME) 1995, proceedings of Ventilation des Batiments: Etat des lieux - Prospective , held Sophia Antipolis, 25-26 October 1995, organised by GEVRA, Groupe d Etude sur la Ventilation et le Renouvellement d Air, pp 186-194.
ABSTRACT This paper presents work to bring into operation an assisted mechanical static ventilator. The objective being in natural ventilation to approach as closely as possible the losses defined by the French 1982 regulation. The minimum characteristics of the apparatus have been defined by calculation with the aid of the GAINE code developed at CSTB. The work showed that the apparatus has the characteristics of a static extractor class B and must have a two speed motor to allow: at slow speeds to provide sufficient air when the thermal motor is insufficient and at fast speeds to allow the evacuation of kitchen pollutants at meal preparation.
KEYWORDS natural ventilation, kitchen, odour
#NO 9333 Household contaminants and household exhaust and ventilation device usage.
AUTHOR Cheple M, Olson W, Klossner S
BIBINF USA, Energy Efficient Building Association, EEBA, 1995, proceedings of the 1995 Excellence in Housing conference, Innovations for Performance , held Minneapolis Hilton and Towers, Minnesota, USA, March 8-11, 1995, pp D44-D57.
ABSTRACT This paper identifies a) the pattern of usage of kitchen and bath fans and clothes dryers in a pilot study of twenty three households with these three appliances and b) the level of contaminants measured in four Minnesota homes when tests were performed as part of a homeowner requested diagnosis of indoor air.
KEYWORDS pollutant, occupant behaviour, kitchen, fan, bathroom
#NO 9527 What s cooking?
AUTHOR Sims B
BIBINF UK, Building Services, December 1995, pp 36-37, 1 fig.
ABSTRACT Considers systems for the ventilation of restaurant kitchens. Commercial kitchen ventilation systems include ventilated ceiling systems such as the Pagula system described. Another approach is the removal cassette system. Lastly the spantile cassette system comprises a series of either aluminium or stainless steel cassette modules suspended away from the ceiling creating a plenum.
KEYWORDS ventilation system, kitchen, ceiling
#NO 9552 Asthma, dust mites, ventilation and air quality: study design and initial carbon monoxide results.
AUTHOR Wiech C, Raw G J
BIBINF Healthy Buildings 95, edited by M Maroni, proceedings of a conference held Milan, Italy, 10-14 September 1995, pp 425-430, 2 tabs, refs.
ABSTRACT The house dust mite (Dermatophagoides pteronyssinus) is found in furnishings in most homes. Although only a fraction of a millimetre in size, it has been identified as an important risk to health because of the allergens both on its enticle and in the faeces. When the allergen becomes airborne, it is a potent provoker of asthma and almost certainly contributed to the 2000 asthma-related deaths which occur each year in the UK.The widespread occurrence of D.pteronyssinus and its potential for causing serious effects on health have prompted research to establish ways of removing it from homes. In principle then, increased ventilation should be capable of reducing indoor humidity and eliminating dust mites. This raises the question of what humidity must be achieved and whether, in practice, ventilation alone can maintain the critical humidity. The critical humidity for dust mite survival has been stated as 7g/kg absolute humidity, equivalent to about 40-45% RH (Korsgard 1982). The Danish results suggest that installing whole-house mechanical ventilation with heat recovery (MVHR) will not only cause a significant reduction in dust mite populations, but bring about a clinically relevant reduction in asthma symptoms. Full MVHR achieves a controlled air flow, ensuring a reliable supply of outside air to all rooms and extraction from moisture-producing rooms (kitchen and bathroom). It is claimed that the clinical benefits are greater than those obtained with any prophylactic drugs. Furthermore, it has been shown (using assumed rates of moisture production indoors) that the critical humidity can be achieved using MVHR for much of a typical winter over much of the UK (McIntyre 1993). In the UK, the outdoor humidity exceeds 7g/kg for 5% of the winter (from December to March) but is generally below 5g/kg during this period. Extracting moist air from the house and replacing it by relatively dry air from outside could therefore reduce humidity levels indoors to below those required for HDM survival. In spite of the existing findings, there are some doubts as to the likely impact of MVHR on mites in UK homes: (a) the critical humidity of 7g/kg is achieved for a smaller proportion of the year in the UK than in Denmark, (b) furnishings and cleaning practices may differ between the two countries and (c) UK homes are typically less tight than those built in Denmark, which will render MVHR less effective. It is therefore important to replicate the Danish work in the UK. To achieve an improvement in asthmatics symptoms it is necessary not only to reduce the number of dust mites but also to remove the allergen already present in the home. The regular use of a high efficiency vacuum cleaner designed to collect dust without recirculating fine dust into the room air is thought to be capable of reducing the allergens reservoir in soft furnishings.
KEYWORDS respiratory illness, dust, biological pollutant, carbon monoxide
#NO 9775 Influence of ventilation way on modelling of CO, CO2, O2 and NOx concentration in gas stove room surrounding.
AUTHOR Gumula S
BIBINF Japan, proceedings of the 5th International Conference on Air Distribution in Rooms, Roomvent '96, held Yokohama, Japan, 17-19 July, 1996, Volume 2, pp 121-127.
ABSTRACT This paper presents the results of experimental tests of ventilation way influence on atmosphere chemical analysis in a room where a gas stove operates. The tests were carried out on real objects and in a typical kitchen room, equipped in two suction systems, a typical air grid joined with an air channel of air movement gravitation input and a local draught ended with an exhaust hood driven by a fan above the tested installation. These tests have shown the concentration of CO2, CO, 02, and NOx
according to the ventilation way. The purpose of this report is to describe the dependences for different values of air flow intensity both in air grid and local suction equipment.
KEYWORDS modelling, carbon dioxide, gas appliance
#NO 9784 Natural ventilation caused by stack effect in large courtyard of high-rise building.
AUTHOR Kotani H, Narasaki M, Sato R, Yamanaka T
BIBINF Japan, proceedings of the 5th International Conference on Air Distribution in Rooms, Roomvent '96, held Yokohama, Japan, 17-19 July, 1996, Volume 2, pp 299-306.
ABSTRACT In the large courtyard of high-rise residential buildings, the exhaust from the kitchen, and the gas water heater, is sometimes discharged into the public corridors, which can pollute the air. The exhaust heat caused the stack effect, so the outdoor air flows through the openings at the bottom of the courtyard to the top. The purpose of this study is to describe these ventilation characteristics and to predict the airflow rate for removing the pollutants. Firstly, model experiments were conducted to know the temperature distribution and airflow rates. The result showed that the characteristics are influenced by the size of the bottom opening area and the position of heat sources. Secondly, the comparison between mathematical calculation and experimental data were nearly in agreement, except for some inconsistencies at the top of the courtyard. This was due to the air down flow, when the bottom opening area was not large enough.
KEYWORDS natural ventilation, stack effect, courtyard, high rise building
#NO 9821 Estimating potential for indoor thermal comfort from natural ventilation.
AUTHOR Aynsley R
BIBINF Japan, proceedings of the 5th International Conference on Air Distribution in Rooms, Roomvent '96, held Yokohama, Japan, 17-19 July, 1996, Volume 3, pp 291-298.
ABSTRACT A 1:100 scale model of a house with a clear plastic roof was placed in a boundary layer wind tunnel. Flow visualisation using foam polystyrene beads was videotaped from above the model for each of 16 compass-point wind directions. Miniature cylindrical hot film anemometer probes were located at an equivalent of 1 metre above floor level in the living room, kitchen and bedrooms from below the wind tunnel floor. A similar reference hot film anemometer probe was mounted upstream from the model at a height equivalent to 10m above ground level.
KEYWORDS thermal comfort, natural ventilation, roof, wind tunnel
#NO 9847 Ventilation in houses with distributed heating systems.
Parent D, Stricker S, Fugler D
UK, Air Infiltration and Ventilation Centre (AIVC), 1996, proceedings of 17th AIVC Conference, "Optimum Ventilation and Air Flow Control in Buildings", Volume 1, held 17-20 September 1996, Gothenburg, Sweden, pp 185-195.
The LTEE laboratory of Hydro-Quebec, in collaboration with Canada Mortgage and Housing conducted an indoor air quality study involving 30 single family detached houses heated with electric baseboard heaters in the vicinity of Trois Rivieres during the 1993-94 heating season. The houses were selected according to the measured air leakage at 50 Pa. so as to have a sample distribution similar to the distribution of air leakage of houses in the province of Quebec. The "source strength" of several air pollutants were calculated from measurements of ambient pollutant levels and total ventilation during a one-week test. In addition, the indoor CO2 and humidity levels were recorded in eight of the houses continuously during the heating season. The level of CO2 in the master bedroom was found to follow fairly closely the CO2 level in other parts of the building including the basement (within about 200 ppm) except when the bedroom door was closed. With the room occupied and the door closed, CO2 levels in the bedroom increased steadily during the night until morning, when the door was opened, to levels in excess of 3 500 ppm with one person, and in excess of 4 500 ppm with two persons. Model studies using the measured pollutant source strengths and measured equivalent leakage areas of the buildings indicated that the recommended health guidelines for airborne respirable solid particles (RSP's), CO2 and formaldehyde are exceeded during periods of low total ventilation, coinciding with mild outdoor temperatures and low wind conditions. It was observed that kitchen and bathroom fans originally installed in some of these houses were not operated by the occupants for sufficiently long times to affect the quality of indoor air. Various different methods of ventilating some of the houses were tested, including quiet replacement exhaust fans, mixing fans for indoor air, and a fresh air intake and mixing system. The effects of operating various air handling systems were monitored by keeping track of indoor CO2 and relative humidity in the master bedroom, and occupancy in person-hours per day. Quiet replacement fans noticeably improved indoor air quality when these were operated over 50% to 100% of the time. An area of remaining concern is the fact that exhaust only systems accentuate the negative pressure in the basement by raising the level of the neutral pressure zone in the building, and may enhance the flow of soil gases into the basement. A system which mixed indoor air between the basement and the main floor also reduced the average level of indoor pollutants. The system was designed to create a pressure difference between the main floor and the basement, causing a slight pressurization of the basement. A system designed to introduce 5L/s of outdoor air and to mix it with 55L/s of indoor air for tempering was installed to draw air from the hallway and deliver the mixed air into each of three bedrooms. This system was capable of maintaining CO2 levels in the master bedroom below 1000 ppm with two occupants in the room and the door closed.
heating system, air leakage, pollutant, carbon dioxide, fan
#NO 9936 Ventilation for humidity control: measurements in a ventilation test house.
Palin S L, McIntyre D A, Edwards R E
UK, Building Serv Eng Res Technol, Vol 17, No 2, 1996, pp 79-84, 4 figs, 1 tab, 15 refs.
Three ventilation systems were installed in a recently refurbished test house: full house mechanical ventilation with heat recovery (MHVR), passive stack ventilation (PSV) and extract fans in kitchen and bathroom. Humidifiers were installed to simulate normal occupancy and behaviour of the ventilation was monitored over the winter of 1993/94. The test house has a low leakage rate of 3 ac h-1 at 50 Pa pressure difference; this low rate was maintained over the duration of the tests. A comparison of ventilation rates provided by the three systems is given. MHVR was the most effective in maintaining low humidity.
air change rate, particle, operating theatre
#NO 10039 The effect of mechanical ventilation on indoor nitrogen dioxide levels.
Wiech C R, Raw G J
Indoor Air '96, proceedings of the 7th International Conference on Indoor Air Quality and Climate, held July 21-26, 1996, Nagoya, Japan, Volume 2, pp 123-128.
A trial was set up to determine the effectiveness of mechanical ventilation with heat recovery (MVHR) in reducing humidity and the effect this has on house dust mite populations in homes occupied by asthmatic patients. The trial included monitoring of a range of factors that might change with the introduction of MVHR and we have an effect on clinical measures of asthma. One such factor was the level of NO2, which was measured in the kitchen, bedroom, living room and outside at 40 homes, before and after MVHR was installed in 20 of these homes. The introduction of MVHR had no significant effect on NO(2) in any room or season even when homes with and without gas cooking were treated separately.
mechanical ventilation, nitrogen dioxide
#NO 10147 Kitchens: a smorgasbord of energy savings.
USA, Home Energy, reprint, 1996, 7pp.
Guide for homeowners introducing energy efficiency measures when remodelling kitchens. Covers layout and design, appliances, lighting, windows and skylights, ventilation, insulation and air sealing, water, household recycling and green building materials.
kitchen, energy saving, retrofitting
#NO 10171 Managing exposure to indoor air pollutants in residential and office environments.
Tichenor B A, Sparks L E
Indoor Air, No 6, 1996, pp 259-270, 10 figs, 18 tabs, refs.
Sources of indoor air pollutants in residential and office environments can be managed to reduce occupant exposures. Techniques for managing indoor air pollution sources include: source elimination, substitution, modification, pretreatment, and altering the amount, location, or time of use. Intelligent source management requires knowledge of the source's emission characteristics, including chemical composition, emission rates, and decay rates. In addition, knowledge of mechanical and natural outdoor air exchange rates, heating/air-conditioning duct flow rates, and local exhaust fan (e.g., kitchen, bathroom) flow rates is needed to determine pollutant concentrations. Finally, indoor air quality (IAQ) models use this information and occupant activity patterns to determine instantaneous and / or cumulative individual exposure. This paper describes a number of residential and office scenarios for various indoor air pollution sources, several ventilation conditions, and typical occupant activity patterns. IAQ model predictions of occupant exposures for these scenarios are given for selected source management options. A one-month period was used to compare exposures; thus, long-term exposure information is not presented in this paper.
pollutant, indoor air quality
#NO 10186 Continuous and passive monitoring of nitrogen dioxide in UK homes.
Environmental Technology, Vol 17, pp 147-155, 5 figs, 3 tabs, 15 refs.
The UK building Research Establishment has carried out measurements of levels of nitrogen dioxide (NO2) in 12 homes in the South of England. Two types of detection device were used: the Scintrex LMA-3 continuous NO2 analyser and the Palmes passive diffusion tube. NO2 concentrations were recorded using both devices in the kitchen, living room and a bedroom of each home for a period of a week. Gas cooking was observed to be the most important source of peak concentrations of NO2 in the home. Six homes, out of the ten that used gas for cooking, had levels of NO2 which exceeded the WHO 1-hr guideline value of 210ppb. In at least two of the homes, personal exposure is expected to have also approached or exceeded this guideline value. There was a fairly good correlation of measured average levels of NO2 between the two detection devices. There was also a fairly good correlation between the 7-day average levels recorded by the diffusion tubes and the maximum 1-hour averages recorded by the continuous detectors. This offers the possibility of gaining information on short-term exposure levels from long-term diffusion tube data. An investigation of the effect of a cooker hood on NO2 levels in a kitchen suggested that it could prove to be an effective means of removing NO2 generated during cooking, especially if there are no other competing means of ventilation such as open doors.
field monitoring, nitrogen dioxide, pollutant
#NO 10352 Evaluation of five simple ventilation strategies suitable for houses without forced air heating.
Reardon J T, Shaw C-Y
USA, Ashrae Transactions, Vol 103, Part 1, 1997, proceedings of the Ashrae Winter Meeting, Philadelphia, 25-29 January 1997.
Houses without forced-air heating systems may not experience adequate distribution of their outdoor air supply. This project examined five simple ventilation systems suitable for such houses. Four were exhaust-only, using either only local exhaust fans in the kitchen and bathrooms or the local exhaust fans supplemented with a partially distributed exhaust system with pickups in each bedroom. Each approach was tested with deliberate passive inlet vents (both distributed and centralised) both open and closed. The fifth system was a supply and exhaust system with small-sized ducts supplying outdoor air to each room and the local exhaust fans providing the exhaust.
The five ventilation systems were installed in a two-storey house that also has an electric forced-air heating system. Using tracer gas techniques, the air distribution patterns provided by each system for a wide range of weather conditions were measured and compared with similar reference measurements in the house with no mechanical air exchange with the outdoors and with only the forced-air furnace fan operating to circulate the air within the house.
The local exhaust fan system with no passive inlet vents was found to provide inadequate distribution of the outdoor air supply, only marginally better than simple air leakage alone. With the distributed passive inlet vents open, the local exhaust fan system was found to distribute more outdoor air to partially distributed exhaust system was effective at improving the ventilation air distribution to the bedrooms. The minimal ducted supply system provided the best outdoor air distribution to all the habitable rooms.
#NO 10412 Evaluation of ventilation effectiveness in the kitchens of Beijing flats.
Nong G, Shen S, Chen T
Indoor Built Environment, No 5, 1996, pp 358-363, 3 figs, 4 tabs, 15 refs.
The effects of different kinds of room ventilation were evaluated in an experimental chamber and in kitchens of four residences in Beijing. Carbon monoxide was used as a tracer gas in the chamber, and this together with nitric oxide and nitrogen dioxide concentrations from the gas appliances were measured in the chamber and the kitchens. The ventilation styles evaluated were natural ventilation, an exhaust fan and a kitchen range hood. Their ventilation effectiveness was related to design, air flow, the distance between an appliance and air vent, and position of the appliance in the kitchen. A kitchen range hood above the appliance associated with an extra fan installed in a high window was found to be the most effective way to control indoor air quality in the kitchens.
kitchen, ventilation effectiveness
#NO 10459 Ventilation of commercial kitchens. La ventilation des cuisines professionnelles.
France, Chaud.Froid. Plomb. November 1996, Vol 50, No 585, pp 89-92.
Sets out the principles of ventilation for medium to large scale commercial kitchens. Outlines the comfort conditions which must be maintained while conserving energy, the principles of ventilation for kitchens, calculation of the air flow rate, systems for capturing fumes, air introduction, measurements and monitoring of air flow rates and fire protection measures.
kitchen, commercial building, air flow rate
#NO 10460 Controlling air change rates in large kitchens. Maitrise des taux de renouvellement d'air dans les grandes cuisines.
France, Chaud. Froid. Plomb., Vol 50, No 585, November 1996, pp 95-99.
Refers to a programme of measurements by Electricite de France (EdF)which demonstrated the considerable impact of ventilation on the energy balance in large kitchens. 30% of the energy consumed in a kitchen is connected with ventilation (heating fresh air). The figures for cooking are 28%, domestic hot water 16%, refrigeration 11%, lighting and others around 15%. Describes a method of ventilation control developed by EdF in the context of reducing electricity consumption, which allows a 40%to 70% reduction in the air flow rates for large kitchens by regulating air extraction as a function of the actual pollutant releases in the kitchen (temperature, humidity, CO2). This reduction depends particularly on kitchen design and the use of energy efficient equipment.
air change rate, kitchen, commercial building
#NO 10540 Schlieren flow visualization in commercial kitchen ventilation research.
Schmid F, Smith V, Swierczyna R
USA, Ashrae Transactions, Vol 103, Part 2, 1997, proceedings of the Ashrae Summer Meeting, Boston, 29 June - 2 July, 1997 [preprint].
kitchen, ventilation system, air flow
#NO 10542 Minimum energy ventilation for quick service restaurants.
Smith V A, Frey P E D, Nicoulin C V
USA, Ashrae Transactions, Vol 103, Part 2, 1997, proceedings of the Ashrae Summer Meeting, Boston, 29 June - 2 July, 1997 [preprint].
kitchen, ventilation system
#NO 10564 Controlling ventilation and space depressurization in restaurants in hot and humid climates.
Cummings J B, Withers C R, Shirey D B
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation and Cooling", 18th Annual Conference, held Athens, Greece, 23-26 September 1997, Volume 1, pp 153-162.
Testing was performed in 9 restaurants to identify uncontrolled air flows and pressure imbalances, building and duct system airtightness, building air barrier location, pressure differentials, building air flow balance, and ventilation rates. All restaurants and depressurized under normal operating conditions, ranging from minus 1.0 to minus 43 pascals. Space depressurization is a function of exhaust fan flow rates, missing or undersized make-up air, intermittent outdoor air caused by the cycling of air handlers, dirty outdoor air and make-up air filters, and building airtightness. Ventilation rates were found to be high, generally exceeding ASHRAE 62-1989 minimum recommended levels. Pressure imbalances and excessive ventilation rates impact energy use, heating/cooling system sizing, indoor comfort and humidity, building moisture damage, mold growth, combustion equipment problems, and indoor air quality. The objective of good restaurant air flow management (in hot and humid climates) are to: 1) achieve positive pressure in the building under a majority of operating conditions, 2) avoid excessive ventilation, and 3) maintain air flow from dining area to kitchen, all while minimizing heating/cooling energy use and achieving acceptable dehumidification (<60% RH most of the time). Recommendations are presented to achieve these objectives.
hot climate, humidity, restaurant
#NO 11044 Air change efficiency in a Chinese kitchen.
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 2, pp 311-316, 1 fig, 1 tab, 4 refs.
To deal with indoor air quality in Chinese kitchens, ventilation plays a key role. In this paper, ventilation in a Chinese kitchen of an apartment is examined. In particular, attention is paid to air change efficiency in the kitchen, which indicates how quickly the contaminates are replaced by fresh air. Air change efficiency is a concept originally developed in Nordic countries. The tracer gas decay method id the most widely used methods of measuring the room mean age of air and determining the air change efficiency of the room. In this paper, the concept is introduced into a Chinese kitchen. Furthermore, air change efficiency and room mean age are calculated with Computational Fluid Dynamics (CFD) method. A commercial program Flovent is used in the calculations. The results show that the CFD method may simulate the trace gas decay method. When windows are opened in a kitchen with cross-ventilation, the air change efficiency in the simulated kitchen is less than 20%.
air change rate, kitchen, pollutant
#NO 11054 The performance of ventilation in Soviet design apartment buildings in Estonia.
USA, Washington DC, Healthy Buildings/IAQ '97, 1997, proceedings of a conference held Bethesda MD, USA, September 27 - October 2, 1997, Volume 3, pp 309-313, 3 figs, 2 refs.
The purpose of the study was to measure the performance of natural ventilation in 5- and 9- storey apartment buildings, and to offer solutions for the improvement of ventilation. In the four most common building types, the functioning of the old ventilation system was measured during a spring and summer period. The economically feasible improvement solutions, as installing the auxilliary fans and mechanical exhaust ventilation, were analysed with measurements and calculations. The old natural ventilation system with stacks and leaky windows can maintain a certain basic level of ventilation. The air change was in an average two-room flat 0,4...0,5 l/h during the measuring period. The simplest and economically most feasible way for improving ventilation is to install in the first stage the kitchen exhaust fans, and in the second stage, the exhaust airflows in bathrooms and toilets can be improved by installing fans on the top of the stacks.
apartment building, building design, ventilation system
#NO 11449 Ventilation alternatives for maritime houses - Final report.
Buchan, Lawton, Parent Ltd
Canada Mortgage and Housing Corporation, May 1986.
Describes a study to examine the effectiveness of low-cost ventilation systems in reducing moisture problems in houses in Maritime climates. A six unit row house block in Dartmouth, Nova Scotia was the subject of the study. The three different ventilation systems that were installed in separate interior units were a humidistat controlled bathroom exhaust fan; a humidistat controlled through-the-wall fan mounted in the kitchen; and a whole house fan, also controlled by a humidistat. All houses had evidence of moisture problems that could be associated with high interior moisture levels. These included mould growth on window frames and in some areas of the ceilings. The findings of the project were that all three fan installations were somewhat effective in limiting exposure of the house to high internal humidity levels. There was not a clear link between control of humidity and reduction of those moisture problems evident in the houses.
residential building, moisture, fan, mould
#NO 11542 Simulation studies on a kitchen ventilation system
Song W W, Tso C P, Yu S C M, Teh S L
UK, Air Infiltration and Ventilation Centre, proceedings of "Ventilation Technologies in Urban Areas", 19th Annual Conference, held Oslo, Norway, 28-30 September 1998, pp 93-100.
The efficiency of a kitchen ventilation system is usually determined by its ability in heat and effluent removal. The main part of a ventilation system is the hood, with its face (or capture) velocity. Heat generation associated with the cooking process is the main factor that affects the thermal comfort. The heat removal capability is studied under different capture velocities so as to determine the minimum requirement for efficient removal of heat and effluent. Four arrangements of make-up air are simulated, with air coming from the front of hood, from the ceiling, from the underneath burner and from the wall. Various angles are also attempted as the direction of the make-up air coming from the wall. Finally the interaction between the kitchen and the refreshment area will be studied. All simulation works were performed using the CFD package, FLUENT (V4.3).
exhaust hood, dining room, computational fluid dynamics, modelling
#NO 11717 A comparison of passive stack ventilation and mechanical extract fans in reducing condensation problems in homes.
Aizlewood C, Brown D, Oseland N
in: UK, Chartered Institute of Building Services Engineers, (CIBSE), "Harnessing Technology for Sustainable Development", CIBSE National Conference 1998, held Bournemouth International Conference Centre, 18-20 October 1998.
A study comparing the effectiveness (as reported by occupants) of passive stack ventilation (PSV) and mechanical extract fans (MEFs) was carried out during the winter of 1996. This involved a face-to-face survey of 437 homes in England. More than 50% of the homes in the study had MEFs, 14% had PSV and 8% had humidistat-controlled MEFs (HMEFs). About 25% of the homes had either a kitchen or a bathroom with no ventilation device, and 16% had no ventilation device in the home.
Four measures of condensation problems were analysed: condensation overall in the home, in the kitchen and in the bathroom, and a combined index of condensation and mould. For the measures analysed, the reported effectiveness of PSV and MEFs was not significantly different. The effectiveness of both, however, was reported to be better than HMEFs.
This report concludes that allowing the use of PSV for dwellings is supported by these results. HMEFs may save energy, but are reported by occupants to be less effective. However, this may be due to problems with their acceptance and use by occupants, rather than any technical failing.
passive stack ventilation, survey
#NO 11731 UK Building Regulations 1991 Ventilation (1995 edition) F1 Means of Ventilation. F2 Condensation in roofs.
UK Department of the Environment
UK, HMSO, 1995, 16 pp.
Replaces the 1990 edition. The main changes are: Background ventilation defined more clearly, provisions improved and the range of examples expanded; passive stack ventilation introduced as an alternative option to mechanical extract ventilation for domestic kitchens, bathrooms and sanitary accommodation; guidance on the use of open-flued combustion appliances for extract ventilation added; provision for opening windows in kitchens added as a supplement to extract ventilation; ventilation of utility rooms added; guidance clarified on reducing the risk of flue gas spillage from open-flued appliances due to mechanical extract ventilation; ventilating to a courtyard omitted; ventilation of common spaces in buildings containing two or more dwellings omitted; provision for ventilation of non-domestic buildings introduced.
building regulations, roof, condensation
#NO 11819 The mystery of the burnt toast.
UK, HAC, February 1999, pp 18-19.
Describes how a new control for kitchen ventilation in student accommodation has reduced false fire alarms. The new design, called a "Cooker Miser" switches the cooker hood ventilator on automatically when cooking appliances are in use, and runs on automatically for a predetermined time period. It is energy efficient, and has the added advantage of reminding occupants to switch off appliances when cooking is finished.
smoke movement, cooker hood, kitchen, communal housing
#NO 12009 Ammattikeittioiden hyvan sisailmaston suunnitteluohje. Design guideline for good indoor climate of commercial kitchens.
Heinonen J, Heinonen J, Salminen M
Finland, Helsinki University of Technology, Laboratory of Heating, Ventilating and Air Conditioning, Espoo 1999, Report B61, 57 pp, in Finnish.
There has been a lack of design guidelines for indoor climate of commercial kitchens. This report is based on the new indoor climate classification of commercial kitchens in Finland. Report gives normative values for indoor air temperature, humidity and air velocity in the kitchen. It also gives guidelines for how to reach the desired level of indoor climate in commercial kitchens by kitchen and ventilation design.
commercial building, kitchen, indoor air quality
#NO 12095 Experimental evaluation of kitchen hoods performance.
Fracastoro G V, Perino M
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 359-366, 9 figs, 1 tab, refs.
This paper presents an original protocol to measure the fluodynamic performance of hoods in the laboratory. Results are presented both in terms of contaminant removal efficiency and flow field.
The measuring campaign has been performed in order to assess how the hood performance is influenced by the boundary conditions, the hood geometry and the heat power released by cooking appliances.
kitchen ventilation, measurement technique, full scale experiments, indoor air quality
#NO 12096 Experimental study on ventilation efficiency in commercial kitchens.
Akabayashi S, Kondo Y, Sakaguchi J, Kawase T
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 367-374, 6 figs, 1 tab, 2 refs.
This paper describes the experimental study of ventilation efficiency for commercial kitchens. We investigated and air conditioning and ventilation system which has high efficiency and which can maintain a comfortable environment in the working space with a minimum amount of necessary ventilation air.
The results are as follows:
(1) In the case of outdoor-air being supplied from the hood, 60-70% of the outdoor-air is exhausted by the hood.
(2) Air flow distribution above the gas range is comparatively stable except in winter, updraft above the gas range flows straight to the exhaust hood when outdoor-air is supplied from the gas range. In winter, updraft above the gas range is strongly effected by the outdoor-air from the hood, and there is dispersion in the updraft direction.
(3) Capture ratio of the combustion gas by the exhaust hood is over 80% except in winter. Capture ration is increased when the caloric output of the gas range is larger.
commercial kitchen, ventilation efficiency
#NO 12097 Numerical simulation of ventilation efficiency in commercial kitchen.
Kondo Y, Akabayashi S, Nagase O, Matsuda A
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 375-382, 10 figs, 5 tabs, refs.
In this paper, the airflow and temperature distributions in a commercial kitchen are simulated based on the k - ( model, and the ventilation efficiency is investigated for three types of ventilation systems. The result of this simulation shows that the suitable supply method of the outdoor air can give high ventilation efficiency, and thus the kitchen can be kept comfortable with relatively low energy consumption.
kitchen ventilation, computational fluid dynamics, ventilation efficiency
#NO 12098 Control of air flows in commercial kitchens.
Heinonen J, Laine T
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 383-390, 11 figs, 5 tabs, refs.
Kitchen exhaust air flow rate should be defined in such a way that it prevents the dispersion of effluents from cooking process into the kitchen and achieve satisfactory thermal conditions by capturing the excess heat that is generated during cooking and frying. Control of air flow rates is one way to influence indoor air quality, thermal conditions and energy economy. Two different air flow control methods were tested during this research. The first stage, was to test manual control where by the users boosted air flow. The second stage, the automatic control method where by flow rates were controlled by wall mounted temperature sensor, was tested. Finally, the measurement results were compared to the simulation results. The conclusion of these control tests was that it is possible to improve thermal conditions and to save heating and fan energy simultaneously. The heating energy savings were 25 to 45%, and fan energy savings 50 to 80% depending on control system. The best control method was VAV system. With simulations it was possible predict thermal conditions and energy consumption quite accurately. The simulations are the best methods for comparing temperature levels and energy consumption reached with different ventilation, and control systems.
kitchen ventilation, thermal comfort, building controls
#NO 12099 Thermal comfort studies in a commercial kitchen environment.
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 391-393, 1 fig, refs.
Thermal comfort issues in a commercial kitchen were studied in a laboratory test series. A commercial instrument was used to predict the thermal comfort of the kitchen personnel working near the hot cooking surfaces. The effect of variables like supply air type and personal nozzles were studied using a thermal comfort meter showing PMV and PPD indices. The results show that the thermal satisfaction was greatly improved with the help of supply air through the hood with low velocity, especially when directed downwards, and using personal nozzles for local cooling, which can be adjusted by the user.
thermal comfort, commercial kitchen, full scale experiments, kitchen ventilation
#NO 12100 Thermal conditions in commercial kitchens.
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 395-399, 2 figs, 5 tabs, refs.
The aim of the research was to find out the indoor climate conditions in Finnish commercial kitchens by measurements and inquiries. Twelve kitchens were selected from the Helsinki metropolitan area. The measurements concentrated on thermal conditions.
On the average thermal conditions in measured kitchens are not fully satisfactory and they varied considerably between the kitchens. Thermal conditions within kitchens varied also depending on the workplace. Heat stress harmful to health was only found in two kitchens. According to measurement, ventilation rates in commercial kitchens should always be based on the loads caused by the cooking equipment.
The research points out that in addition to the air flows the supply air temperature also has a direct influence to the temperature of the indoor air in the workplace. To guarantee acceptable thermal conditions the air flow rates and the temperature of the supply air must be controlled.
air conditioning, air velocity, kitchen ventilation, temperature gradient, thermal comfort
#NO 12189 The control of air quality in a Chinese kitchen.
Duanmu L, Ao Y, Feng G
UK, Garston, BRE, 1999, proceedings of Indoor Air 99, the 8th International Conference on Indoor Air Quality and Climate, and the Air Infiltration and Ventilation Centre (AIVC) 20th Annual Conference, held Edinburgh, Scotland, 8-13 August 1999, Volume 1, pp 24-29.
Chinese food is delicious. There are many kinds of cuisine. But the stir-fry, f~ and deep-fry produce a large amount of steam and smoke which cause indoor air pollution seriously. So it must be controlled. The paper gets some flow distribution regularity of steam and smoke current in Chinese cooking by testing in laboratory and advances a new method to prevent the diffusion of smoking current-kitchen hood with forced air screen. 33y comparing with other removers, the equipment can save heat (cold) load and improve indoor air condition greatly. The paper also analyses blow and draw current of the equipment by fluid mechanics theories.
commercial kitchen, steam, smoke, cooker hood
#NO 12244 Influence of ventilation systems on aerosol and vapour concentration in the kitchen.
Andrejs B, Neumann P, Huber J, Schmeja B
UK, Garston, BRE, 1999, proceedings of Indoor Air 99, the 8th International Conference on Indoor Air Quality and Climate, and the Air Infiltration and Ventilation Centre (AIVC) 20th Annual Conference, held Edinburgh, Scotland, 8-13 August 1999, Volume 2, pp 338-343.
During the experiments and under the experimental conditions, displacement ventilation with air outlets close to floor level were found to produce the lowest concentrations of hazardous substances and aerosols in the working areas of kitchen appliances when compared with mixed or displacement ventilation through ceiling outlets. Displacement ventilation with low-induction ceiling outlets achieved better results than mixed ventilation. Since the experimental setup had been selected specifically for its closeness to practical conditions, it can be expected that arrangement of appliances and, consequently, any additional space requirement must be taken into account in practical scenarios.
#NO 12253 A field experiment on indoor consistency distribution of combustion gas by ventilation performance of range hood.
Roh J W, Kim J T
UK, Garston, BRE, 1999, proceedings of Indoor Air 99, the 8th International Conference on Indoor Air Quality and Climate, and the Air Infiltration and Ventilation Centre (AIVC) 20th Annual Conference, held Edinburgh, Scotland, 8-13 August 1999, Volume 2, pp 387-392.
In apartments of Korea, exhaust-only hood system is commonly installed for kitchen ventilation. However, as to resident's increasing complaints recently due to poor indoor air quality and hood noise, a careful review regarding kitchen ventilation system came to be in need. This paper presents a research that was conducted to improve ventilation problems in the existing kitchen of apartments. For this purpose, a field test has been carried out to examine the effect of range hood's exhaust airflow rates, and makeup air inlet's settings on kitchen ventilation efficiency. The results show that the proper application of makeup air inlet is useful for mediating indoor air pollution by combustion gas emitting from the cooking appliances.
combustion appliance, cooker hood
#NO 12289 The influence of an architectural design alternative (transoms) on indoor air environment in conventional kitchens in Taiwan.
Chiang C-M, Lai C-M, Chou P-C, Li Y-Y
UK, Garston, BRE, 1999, proceedings of Indoor Air 99, the 8th International Conference on Indoor Air Quality and Climate, and the Air Infiltration and Ventilation Centre (AIVC) 20th Annual Conference, held Edinburgh, Scotland, 8-13 August 1999, Volume 4, pp 328-333.
This study investigates indoor air environment via the flow fields, temperature fields and air contaminants (carbon monoxide) distributions in conventional residential kitchens, and looks for effective methods to solve those problems through natural ventilation techniques. Numerical simulations of the physical problem under consideration have been performed via a finite volume method for solving the governing equations and boundary conditions. It is obvious that location of accumulation of air contaminants is highly relevant to the location of gas fires, and realising the dominant flow pattern will be successful in eliminating air contaminants. An architectural design alternative, utilising transoms, is then proposed to improve indoor air environment in kitchens.
building design, kitchen
#NO 12407 Roomvent '98 6th international conference on air distribution in rooms. Volume 2.
Mundt E, Malmstroem T-G (eds.)
Sweden, Stockholm, KTH, 1998, proceedings of a conference held Stockholm, Sweden, June 14-17, 1998, 624 pp.
Volume 2 of the conference contains papers from the following sessions: applications, large spaces; flow systems, jets and supply air terminal devices; calculations and measurements, heat transfer in rooms; IAQ and comfort, influence of the surroundings on humans; applications, auditoriums and museums; flow systems, ventilation effectiveness; calculations and measurements, room air movements; IAQ and comfort, thermal comfort; applications, kitchens; flow systems, natural ventilation; calculations and measurements, tracer gas and air exchange measurements; applications, livestock buildings and industries; flow systems, air flow between rooms and through windows; calculations and measurements, velocity measurements.
indoor air quality, ventilation system
#NO 12410 La ventilation des cuisines collectives. Ventilation of large kitchens.
France, Chaud Froid Plomb., No 612, 1999, pp 47-55, 13 figs, 10 tabs.
Analyses the complex standards and regulations in France governing the use of cooker exhaust hoods in commercial kitchens.
commercial building, kitchen, cooker hood
#NO 12664 Protection of kitchen extracts.
Proceedings VHExCo 99, International Ventilation Hygiene Conference and Exhibition, Solihull, UK, March 24-25, 1999, 4 pp, BSRIA/Criterion Publishing Ltd.
Provides a brief overview of the traditional approach taken to grease and odour control in kitchen extract systems. Describes a new technology recently developed in Denmark for destroying airborne cooking grease and odours using ultraviolet enhanced oxidation technology. Hot, dirty air containing vaporised cooking oil, water vapour and entrained fat passes over special UV light tubes installed behind the grease traps in a kitchen canopy or in the ducting, where the fatty deposits and odours are broken down and destroyed. Traces of ozone left in the air gradually destroy grease previously laid down in the ducting. Explains the chemistry and gives application examples in Denmark. Explains operation, maintenance and cost savings. Lists the claimed advantages of the system.
kitchen, cooker hood, grease, odour
#NO 12670 Insurance and kitchen extraction.
Proceedings VHExCo 99, International Ventilation Hygiene Conference and Exhibition, Solihull, UK, March 24-25 1999, 8pp. BSRIA/Criterion Publishing Ltd.
Describes the fire hazard posed by kitchen extract ducts, with the current trend to fewer smaller fires and a smaller number of far bigger fires. Cites some recent examples. Points to the overwhelmingly important factor of inadequate cleaning of ductwork downstream of the fire suppression system. Notes the need for a formal risk assessment to be carried out to determine the degree and frequency of cleaning needed. Discusses adequate fire protection systems and adequate ductwork standards. Goes on to examine liability insurance of contractors, and gives advice about doing what is required and also being able to prove it.
cooker hood, fire hazard, grease, duct cleaning
#NO 12801 From ruin to rehab.
USA, Home Energy, May/June 2000, pp 24-30.
Describes how boiler mechanic Henry Gifford and architect Chris Benedict worked together to perform a major energy efficient rehabilitation exercise on several abandoned and badly deteriorated wood frame and masonry structures in New York City. The buildings had been in such poor shape that they required major rehabilitation, and the work done to them blurred the distinction between renovation and new construction. They were rehabilitated into multifamily homes of two, three or four apartments each. The work was completed despite considerable doubts on the part of the developer that introducing sustainable and energy efficient design would be too expensive, and would make the homes too difficult for the contractors to construct and for the homeowners to operate. For ventilation, constantly running individual exhaust-only systems for each apartment were chosen. Trickle ventilators were installed in each bedroom to supply fresh air. The system pulled outdoor air through the trickle ventilators in each bedroom, through the common areas, and out of each bathroom and kitchen. Occupant response was favourable. They were pleased to be able to control individual room temperatures, and noted that the houses were unusually quiet (likely due to the good air sealing). Despite the success of the project, the developer and city housing department specifically excluded energy efficient design for the next round of rehab housing the following year.
multifamily building, apartment building, rehabilitation
#NO 12827 The influence of an architectural design alternative (transoms) on indoor air environment in conventional kitchens in Taiwan.
Chiang C M, Lai C M, Chou P C, Li Y Y
Building and Environment, No 35, 2000, pp 579-585, 14 figs, 3 tabs, 11 refs.
This study intends to investigate indoor air environment via the flow fields, temperature fields and air contaminant (carbon monoxide) distributions in the conventional residential kitchens, and look for effective methods to solve problems through natural ventilation techniques. Numerical simulations of the physical problem under consideration have been performed via a finite volume method for solving the governing equations and boundary conditions. It is obvious that location of accumulation of air contaminants is highly relevant to the location of gas fires, and using the residential range hood will be successful in eliminating air contaminants. An architectural design alternative, utilizing transforms, is proposed to improve indoor air environment in kitchens.
building design, kitchen, residential building
#NO 12828 Koneellisen poistoilmanvaihdon parantaminen. Radon, vuotiolma ja korvausilma. Improvement of mechanical exhaust ventilation in apartment buildings. Radon leakage flows and intake air.
Kurnitski J, Jokiranta K, Matilainen M
Finland, Helsinki University of Technology, Laboratory of Heating, Ventilating and Air Conditioning, Report B65, Espoo 1999, 77 pp, in Finnish.
The objective of this research was to find improvements for the mechanical exhaust ventilation, which will enable the reduction of draughts, limit leakage flows and reduce radon concentrations, improve the duration of intake air flows and the control of air change. In the research, a new intake air device that turns intake airflow uniformly back to the radiator was tested in two apartments, where conditions were monitored before and after installing air intakes. In addition, instant measurements were carried out in seven detached houses and in seven apartments. The behaviour of mechanical exhaust ventilation and the need for control was assessed by computer simulation, where the effects of the number of air intakes, location and tightness of the building, etc, on the pressure conditions and air flow were studied. A general conclusion from the simulations was that mechanical ventilation will not function in the case of windy building sites. At an open building site, the reverse flows in air intakes could not be avoided and, in opposite facades, large asymmetry in intake air flows was formed. Leakage flow through the base floor to apartments cannot be avoided according to the results of simulation and measurements. Air tightness of the base floor is lower compared to the other parts of the building envelope due to ducts and pipes leading through and a notable amount of intake air can be leaked through the base floor. The common air intakes can transport into the room, without notable draught, 10 l/s airflow that consists of 6 l/s airflow through the vent and 4 l/s leakage of the façade. This airflow corresponds to an air change rate of 0.5 ach that can be recommended for air change during day and night without timer-control since the ventilation load is most critical during night. Even in small apartments 0.5 ach air change can be dimensioned by reduced extract flow in the kitchen by a controlled range hood and, if necessary, by reduced extract flow in the bathroom.
mechanical exhaust ventilation, draughts, radon, air leakage, apartment building
#NO 13100 Laboratory dust loading test method of exhaust air terminal devices.
Bernard A-M, Ginestet A, Lemaire M-C, Beltzer P
UK, Air Infiltration and Ventilation Centre, proceedings of "Innovations in Ventilation Technology", 21st AIVC Annual Conference, held The Hague, Netherlands, 26-29 September 2000, paper 51.
Loading of ventilation components with dust may affect air handling systems performances and contribute to poor indoor air. A lot of standardised test methods for ventilation components characterisation - filters, fans, heat exchangers, extract air terminal devices etc. - exist but all these methods describe initial performance determination except for filters which are also characterised by dust loading test.
The aim of our study was to define a laboratory dust loading test method of extract air terminal devices and to validate results comparing to on-site results. As extract air terminal devices are commonly used in kitchens and bathrooms, dust loading may include solid particles and sticky particles.
Dust loading test results show a good reproducibility. Air flow measurement of naturally loaded devices show that the visual appearance can be not representative of the loading level. Naturally loaded devices show a large diversity but the loading effect is of the same order as artificial loading. Bathroom loadings, generally less sticky, can be represented in average by an artificial test with ASHRAE dust (EN 779) only while the adjunction of oil represents better kitchen loaded devices. Performances of the cleaned devices are similar to those of the new one except in case of very high loading characteristics.
dust, ventilation performance, air terminal device
#NO 13110 Pollutant dispersion simulated with tracer gas in a naturally ventilated test house.
Bassett M R
UK, Air Infiltration and Ventilation Centre, proceedings of "Innovations in Ventilation Technology", 21st AIVC Annual Conference, held The Hague, Netherlands, 26-29 September 2000, paper 61.
The New Zealand Building Code has kept with tradition in allowing residential building ventilation designs based entirely on openable window areas. Working against this tradition, however, is a trend in New Zealand towards more airtight construction and declining reliance on open windows. Contributing to this trend are changing patterns of occupancy with fewer people at home during the working week, along with developing concerns for personal security. The research described in this paper is developing new ventilation strategies for single family residential buildings based on combinations of passive and simple mechanical systems. A series of measurements are described which used a tracer gas to simulate pollutant dispersion in a multi-room test house. The tracer was released at a constant rate in kitchen and bathroom locations with natural and mechanically assisted ventilation strategies in place. The building was operated in four modes reflecting two levels of building airtightness and with internal doors either open or closed. Results are expressed in terms of the mean age of air and the mean age of the pollutant averaged over periods of several days.
The first order effect of the different ventilation strategies was to control tracer concentrations about as effectively as a dilution ventilation system. While concentration differences were seen in the different rooms at breathing height, these were generally smaller than would have been expected to develop under static driving forces and with limited internal mixing, and are not overly significant in the context of limiting pollutant exposures within the building. Pollutant removal in the house is presented as a relative contaminant removal effectiveness averaging over the air volume and over time periods of at least a day. It is clear that the constantly changing driving forces of infiltration reduce some of the potential contaminant removal efficiencies that might be anticipated and that closed internal doors effectively partition the building into multiple zones. Although only one building has been examined, the results signal some simplifications in the way natural and single point mechanical ventilation systems are sized to meet ventilation requirements in code documents.
pollutant, tracer gas, test house, natural ventilation