What is cross ventilation in homes
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Stale air can hold moisture and cause mold. It can also smell bad, and make a building uncomfortable to be in for an occupant. Without a supply of new air, sources of irritation and allergy in the air, such as dust or hair, can also adversely affect health. A typical house contains several features that allow fresh air in and stale air out. Windows and wall vents are the most common options. These entrances and exits for air are passive features of a building. Even though vents and windows are traditional methods, engineers and architects can still design them for optimum efficiency to suit a particular building.
The basis of cross ventilation involves specific differences in air pressure between incoming and outgoing air.Natural Wind Driven Cross Ventilation - Explainer Video
As building interiors tend to be warmer than the outside environment in cool climates, the interior air is at a low pressure, as it expands with heat. The cooler air outside has a high pressure as it is denser with the cold. Another source of pressure differential, which is important in both cool and hot climates, is the wind. Wind provides outside air with more force than the air inside the building. Both of these sources of pressure tend to drive the air into buildings.
The air comes in through the entrance, which is a window or vent on the side of the building that faces the wind.
Turbines are available in 12 and 14 inches. The inch turbines provide about 30 percent more airflow.
What Windows are Best for Cross-Ventilation
Open windows on opposite sides of the house to create a cross breeze and turn on a ceiling fan. Open the doors to interior rooms to allow air to flow throughout the house. A large, airy, "great room," as they are sometimes called, is an open area of your home that begs to be filled Cross-ventilation is generally the most effective form of wind ventilation.
Cross-ventilation bottom images is more effective than ventilation that does not pass through the whole space top images. It is generally best not to place openings exactly across from each ventilation in a space. While this does give effective ventilation, it can cause some parts of the room to be well-cooled and ventilated while cross parts are not. Also, you can increase cross ventilation by having larger openings on the leeward faces of the building that the windward faces and placing inlets at higher pressure zones and outlets at lower home zones.
Different amounts of ventilation and air mixing with different windows what. Placing inlets low in the room and outlets high in the room can cool spaces more effectively, because they leverage the natural convection of air. Cooler air sinks lower, while hot air rises; therefore, locating the opening down low helps push cooler air through the space, while locating the exhaust up high helps pull warmer air out of the space. Regularly occupied spaces include living rooms,bed rooms,dining rooms,study rooms,kitchen etc. Cross ventilation helps us breathe better, think better.
It has a lot more benefit than we imagine. However, by the late s, scientists thought biological contamination, not oxygen or CO2, as the primary component of unacceptable indoor air. However, it was noted as early as that CO2 concentration closely correlates to perceived air quality. The first estimate of minimum ventilation rates was developed by Tredgold in Study continued into the varied effects of thermal comfortoxygen, carbon dioxide, and biological contaminants.
Research was conducted with humans subjects controlled test chambers. Two studies, published between andshowed that carbon dioxide was not the offending component. Subjects remained satisfied in chambers with high levels of CO2, so long as the chamber remained cool.
ASHVE began a robust research effort in ByASHVE funded research conducted by Lemberg, Brandt, and Morse - again using human subjects in test chambers - suggested the primary component of "bad air" was odor, perceived by the human olfactory nerves.
At lower, more comfortable temperatures, lower ventilation rates were satisfactory.
A human test chamber study by Yaglou, Riley, and Coggins culminated much of this effort, considering odor, room volume, occupant age, cooling equipment effects, and recirculated air implications, which provided guidance for ventilation rates. Ventilation for acceptable indoor air quality.
What Is Cross Ventilation?
As more architecture incorporated mechanical ventilation, the cost of outdoor air ventilation came under some scrutiny. In cold, warm, humid, or dusty climates, it is preferable to minimize ventilation with outdoor air to conserve energy, cost, or filtration.
However subsequent research by Fanger,  W. Cain, and Janssen validated the Yaglou model. ASHRAE continues to publish space-by-space ventilation rate recommendations, which are decided by a consensus committee of industry experts. Inthe calculation method was revised to include both an occupant-based contamination component and an area—based contamination component. The change was made to recognize that densely populated areas were sometimes overventilated leading to higher energy and cost using a per-person methodology.
The addition of occupant- and area-based ventilation rates found in the tables above often results in significantly reduced rates compared to the former standard.Ventilation (architecture)
This is compensated in other sections of the standard which require that this minimum amount of air is actually delivered to the breathing zone of the individual occupant at all times. The total outdoor air intake of the ventilation system in multiple-zone variable air volume VAV systems might therefore be similar to the airflow required by the standard. From tothere was considerable development of the application protocol for ventilation rates. These advancements address occupant- and process-based ventilation rates, room ventilation effectiveness, and system ventilation effectiveness .
The design of buildings that promote occupant health and well being requires clear understanding of the ways that ventilation airflow interacts with, dilutes, displaces or introduces pollutants within the occupied space.
Although ventilation is an integral component to maintaining good indoor air quality, it may not be satisfactory alone.
In kitchen ventilation systems, or for laboratory fume hoodsthe design of effective effluent capture can be more important than the bulk amount of ventilation in a space. More generally, the way that an air distribution system causes ventilation to flow into and out of a space impacts the ability for a particular ventilation rate to remove internally generated pollutants.
The ability for a system to remove pollution is described as its "ventilation effectiveness". However, the overall impacts of ventilation on indoor air quality can depend on more complex factors such as the sources of pollution, and the ways that activities and airflow interact to affect occupant exposure.
Techniques and architectural features used to ventilate buildings and structures naturally include, but are not limited to:. Natural ventilation harnesses naturally available forces to supply and remove air in an enclosed space.
There are three types of natural ventilation occurring in buildings: Seoul University Professor Wonjun Kwon recently discovered a new way to ventilate large area of indoor space.
The so-called "air pump" system uses pressure between inside and outside of rooms to push air out of a structure. Almost all historic buildings were ventilated naturally.
Mechanical ventilation of buildings and structures can be achieved by use of the following techniques:.