Occupied Mode: Total supply air, Air Changes per Hour, Air Velocity at Ceiling Diffuser
As described in the 2009 ASHRAE Handbook--Fundamentals, (18) the airflow pattern in cooling mode from a flush-mounted ceiling diffuser
is projected downward to the floor and follows it, producing a stagnant region near the ceiling.
A typical TDD consists of three parts (Figure 1): a collector located on the roof to gather daylight; a hollow tubular light guide in the plenum/attic space to channel the collected daylight to its intended destination; and a ceiling diffuser
to spread the daylight indoors.
The company also offers an 'air supply' version of the product that can be installed on the ceiling or wall, instead of a ceiling diffuser
or a wall grill.
You'll see a clear-bubble dome on the roof that gathers natural light and transfers it down a highly polished round pipe taking it around tricky twists and turns, to a ceiling diffuser
panel that is the proverbial "light at the end of the tunnel." It's an awesome new force in both new homes and remodeling
This feature makes the thermometer ideal for measuring the temperature of ventilation air coming through a ceiling diffuser
. A large straightened paper clip serves well as a hanger.
However, the highest acceleration in the centerline velocity occurs between 36 to 38 percent of the vertical distance from the ceiling diffuser
irrespective of the supply airflow rate (Khankari 2017a).
The system shown in Figure 3 supplies air to the room at 14[degrees]C (57.2[degrees]F) via a 0.8 m x 0.8 m (2.62 x 2.62 ft) perforated ceiling diffuser
. The supply air temperature is chosen to achieve a temperature difference capable of accomplishing low velocity and comfortable conditions as per the ASHRAE requirements (ASHRAE 1999).
The supply air entering the cleanroom from the ceiling diffuser
flows straight down behind the operator and exits from the two returns located on the opposite side walls of the room.
In present study, the gases and particles dispersion in three representative ventilation rooms: 1) room with a ceiling diffuser
; 2) room with a side wall slot diffuser with height of 1.5 m [4.92 ft] and 3) room with a displacement ventilation diffuser at floor level were compared to examine the impact of the diffuser arrangement on the pollutant distribution.
The supply air entering in the room from the ceiling diffuser
flows straight downward behind the operator and exits from the two returns located on the opposite side walls of the room.
Different ceiling diffusers
arrangements were already predicted, Khalil et al (2013) that showed the various effects of ceiling diffuser
design, shape and location.