Air Grille
Air Grille
Air Grille is a component of compressed air piping system. Air Grille can be called in various name and operated in several functions as follows;
Supply Air Grille
Supply Air Grille is positioned at the mount of supply air pipe for cooling air diffusion and attraction. There are following several forms of Supply Air Grille, functioning as air supply ; Square Diffuser for 4, 3 or 2 ways air supply , Rectangular Diffuser, Slot Diffuser with 1-4 slots or more, Register and Jet Diffuser. The Supply Air Grille, compatible with VAV system should be capable of supplying cooling air along with ceiling (based on air speed and lifting force, similarly to the lifting force of the wings of aircraft, technically called Coanda Effect against the drop of cooling air when the air supply is faded down. The special Supply Air Grille called Low Temp Diffuser is available in the air-conditioning system with supplement cool thermal storage system, like ice storage, with low temperature. It is efficient in induce effect for better airflow because the low temperature air can reduce the air supply volume. To maintain the normal airflow, the Supply Air Grille, efficient in increasing the ratio of internal airflow to the supplied cooling air is required. For this special Supply Air Grille, water drop arisen from the cooler air cannot not be found.
Return Air Grille
Return Air Grille
Return Air Grille is located at the mount of return air for attraction. Normally, the air speed of Return Air Grille will be around 400-600 ft/minute. If the Return Air Grille is installed close to the Supply Air Grille, the required air speed should not be higher than half of the speed of Supply Air Grille to avoid an electrical short of the returned air to the returned air tunnel. It is remarkable that for wall-type air conditioner, the Return Air Grille will be much bigger than the Supply Air Grille.
Exhaust Air grille
Exhaust Air Grille is used to discharge air. It looks like the Return Air Grille but smaller. The operator should pay attention on rainproof, windproof and insects issues for the part of Exhaust Air Grille, blowing the air outward.
Fresh Air Grille
Fresh Air Grille is the grill located on the wall or ceiling in outdoor area for receiving inward airflow. The operator should also pay attention on rainproof, windproof and insects issues. Fresh Air Grille should not be positioned around polluted air or bad smell area.
Air Damper
Volume Damper functions for air volume adjustment. It should be installed around affiliated pipes in the compressed air piping system.
Motorized Damper
Motorized Damper functions for air volume adjustment, with its motor driving the air adjusting blade to open at the needed level.
Fire Damper
Fire Damper is used to close the compressed air piping system to block the transmission of air or flame in case of fire accident. Its function is based on the melt of fusible link, allowing fire-resistant valve close by its weight when degradation.
Smoke Damper
Smoke Damper functions as Fire Damper but most of Smoke Damper is motorized for operation and co-functions with fire alarm system. Smoke Damper will be off in area of smoking in order to block a passage of smoke into the compressed air piping system.
Gravity Damper
Dampers should not be used in the pipe containing polluted air, such as, air-vent pipe in the kitchen or laundry chamber because grease or stain can dirt the air adjuster blade, make it immobilized and can be optimized at the time of air adjustment after completion of installation only.
Dampers should not be used in the pipe containing polluted air, such as, air-vent pipe in the kitchen or laundry chamber because grease or stain can dirt the air adjuster blade, make it immobilized and can be optimized at the time of air adjustment after completion of installation only.
Air Filter
For any offices in Bangkok without smoking prohibition in the working area, it can be found 800,000-1,000,000 of 0.05 micron dust. But , for any offices in Bangkok equipped with good air filtering system, the volume of 0.05 micron dust is only 100,000-300,000 and it is reported with low rate of illness and flu attack for their employees (from my working experience)
Air Filter filters dusts in the air to refresh air in the air-conditioning room. Today, people become pay more attention to Indoor Air Quality because the health of workers depends on Indoor Air Quality and dust and particles in the air is the cause of illness and allergies.
Today, there are many brands of air filter, efficient in reducing dust volume in the air.
There are many types of air filter in the air conditioner. The type applied with a small air conditioner is mostly made of light synthetic fiber, and cleaned by soaking in the water (washable type). Aluminium filter with the thin frame is also available. This type of air filter is 1-2 inches thickness and removable for cleaning. Aluminium filter is 10-20% efficient in dust reduction property.
For more efficient air filter, this type of air filter is mostly made of paper with 2-24 inches layers depth, 2 ft x 2 ft size (the measures are inch and foot for American system). The percentage of its efficiency in dust reduction is 70-99.99%. Due to high cost and friction of high quality air filter, this type of air filter is mostly protected at front by low and medium quality one to avoid pre-matured blockade.