Why is ventilation necessary? Ventilation is needed to provide oxygen for metabolism and to dilute metabolic pollutants (carbon dioxide and odour). Ventilation is additionally used for cooling and (particularly in dwellings) to provide oxygen to combustion appliances.
What is tunnel ventilation?
Tunnel ventilation is a system where exhaust fans are located at one end of the house and two large openings are installed at the opposite end. Air is drawn through these openings, down the house, and out the fans, like a wind tunnel (see Figure 1). Tunnel ventilation is a type of exhaust system.
How ventilation is provided in tunnels?
Mechanical Ventilation System in Tunnels
Mechanical ventilation system employs mechanical devices like electric fans, exhaust, and blowers, which serves the function of removing the exhaust gasses within the tunnel and help in blowing fresh air into the tunnel.
What is ventilation and why it is necessary?
Ventilation refers to the process by which ‘clean’ (normally outdoor) air is intentionally supplied to a space, while stale air is removed. Ventilation is especially required for commercial and industrial spaces to control indoor air quality by diluting and displacing indoor pollutants.
What is the purpose of ventilation in your house?
Ventilation refers to the exchange of indoor and outdoor air. Without proper ventilation, an otherwise insulated and airtight house will seal in harmful pollutants, such as carbon monoxide, and moisture that can damage a house. Proper ventilation helps keep a home energy-efficient, safe, and healthy.
Related faq for Why Is Ventilation Necessary?
What type of ventilation should be adopted where necessary in tunneling?
This type of ventilation method is suitable for short length tunnel. In this system of ventilation, Fresh air is blown by blower installed in the input shaft. Blowers provide a uniform distribution of fresh air at the workplace, and the vitiated air is pushed out through the portals.
What are the types of ventilation?
There are three methods that may be used to ventilate a building: natural, mechanical and hybrid (mixed-mode) ventilation.
What is drift method of tunneling?
In this method after driving the drift, the drill holes are drilled all round the drift in the entire cross section of the tunnel, filled with explosives and ignited. The rock shatters, the muck removed and the tunnel expanded to the full cross section.
Which of the following method provides the most efficient ventilation system of tunnels?
Combination of blowing in and exhaust system
This method is generally considered as the most efficient system for ventilation of tunnels.
Which method of tunneling is used for laying underground sewers?
ARMY METHOD OR CASE METHOD
Army Method Devised By US Army For Construction Of Small Tunnel At Fairly Shallow Depth. This Method Mainly Used For Laying Underground Sewers.
Which one of the following method is adopted for tunneling in soft soil?
For tunnelling in soft soil, Needle beam method is adopted. The needle beam consists of a stout timber beam or a composite flitched beam and form a main temporary support during the excavation.
Why Proper ventilation is important in a workshop?
Proper ventilation allows detainees to breathe normally, evacuates humidity from their cells and gets rid of bad odours.
What do you understand by ventilation?
Purpose provided (intentional) ventilation: Ventilation is the process by which ‘clean’ air (normally outdoor air) is intentionally provided to a space and stale air is removed. This may be accomplished by either natural or mechanical means. The corresponding loss of air from an enclosed space is termed ‘exfiltration’.
How does the ventilation system work?
Exhaust ventilation systems work by depressurizing the building. By reducing the inside air pressure below the outdoor air pressure, they extract indoor air from a house while make- up air infiltrates through leaks in the building shell and through intentional, passive vents.
What is benching in tunnel?
In large tunnels and when the quality of the rock is not satisfactory, heading and benching method is often used. This method involves the driving the top portion of the tunnel in advance of the bottom portion. The lining of roof arch can then be constructed first by using the bottom bench as temporary supports.
What is tunnel survey?
Tunnel Survey is that branch of survey that is concern with the surveying in a tunnel. This type of survey is required in mining works, deep tunnel sewerage works and underground railway works. In tunnel survey, laser total stations are used to give alignment together with gyroscopic instrument.
What is Tunnelling in civil engineering?
Tunnels are underground constructions used for transportations. The operations and the constructions are carried out underground without disturbing the ground surface. This operation is called as the tunneling. Contents: Construction of First Tunnel.
What are the effects of ventilation?
The existing literature indicates that ventilation has a significant impact on several important human outcomes including: (1) communicable respiratory illnesses; (2) sick building syndrome symptoms; (3) task performance and productivity, and (4) perceived air quality (PAQ) among occupants or sensory panels (5)
Do all rooms need ventilation?
Each new room in a house should have adequate ventilation for general health reasons. The type of room will determine how much ventilation is required. The opening should have a typical area of at least 1/20th of the floor area of the room served, unless it is a bathroom which can be any openable size.
Which of the following explosive is used for tunneling in soft rocks?
Ammonia Dynamite is used as an explosive for tunneling in soft rocks.
What is the purpose of tunnel?
Tunnels are underground passages used for transportation. They could be used for carrying freights and passengers, water, sewage, etc Tunnels are more economical than open cuts beyond certain depths. Tunnels avoid disturbing or interfering with surface life and traffic during construction.
How do tunnels work?
Tunneling works by encapsulating packets: wrapping packets inside of other packets. Tunneling is often used in virtual private networks (VPNs). It can also set up efficient and secure connections between networks, enable the usage of unsupported network protocols, and in some cases allow users to bypass firewalls.
How do tunnels get built?
Tunnels are dug in types of materials varying from soft clay to hard rock. Cut-and-cover tunnels are constructed in a shallow trench and then covered over. Bored tunnels are constructed in situ, without removing the ground above. Finally, a tube can be sunk into a body of water, which is called an immersed tunnel.
How many classes of tunnels are there?
Explanation: Geologically speaking, only two classes of tunnels are recognized: tunnels driven through rocks (rock tunnelling) and tunnels driven through soil, loose sediments or saturated ground (soft-ground tunnelling).
Which is a component of shield for tunneling?
A tunnel boring machine (TBM) consists of a shield (a large metal cylinder) and trailing support mechanisms. A rotating cutting wheel is located at the front end of the shield.
Which one of the following method of tunneling is used in hard rock?
The heading and Benching method of tunneling is used in hard rock cutting. The tunnel cross-section is divided into two parts, the top portion of the tunnel is known as the heading, and the bottom portion is a bench. Usually, this method is adopted for railway tunnels.
What is ventilation and what is importance of ventilation in engineering workshop?
Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of indoor environment, or other objectives.