What is an underfloor air distribution system?
Underfloor air distribution (UFAD) is a method to provide ventilation and space conditioning in offices and other commercial buildings. UFAD uses the open space between the structural concrete slab and a raised floor system, to carry conditioned air directly into building zones.
What are some of the advantages and disadvantages of underfloor air distribution?
The main advantage of active diffusers is more individual control, which can increase comfort and productivity (Crockett 2002). The primary disadvantage is that small fractional horsepower fans can be less efficient than a large central fan, however fractional horsepower motor efficiency continues to improve.
How does underfloor air conditioning work?
The Benefits of an Underfloor System Vents are on the floor, so cool air is pumped directly into the room. Because hot air rises, this makes for a more energy-efficient airflow. Vents are powder coated and can be colour matched to blend with the home’s aesthetic and each room if required.
What are the different methods of air distribution?
(a) Mixing ventilation, (b) Displacement ventilation, (c) Diffuse ceiling ventilation.
Where is underfloor air distribution often found?
Underfloor air distribution is frequently used in office buildings, particularly highly-reconfigurable and open plan offices where raised floors are desirable for cable management.
What is a raised floor called?
Raised floor systems, also known as access floors, are an elevated structural floor that is stabilized over a solid substrate, typically a concrete slab. Since the pedestals are adjustable, the gap between the elevated floor and the subfloor can be between 3 and 48 inches. …
Which underfloor air distribution system provides the opportunity for individual occupant control of the air flow?
UFAD systems have several potential advantages over traditional ceiling-based air distribution systems. Well-engineered systems can provide: Improved thermal comfort. By allowing individual workers to have some amount of control over their local thermal environment, individual comfort preferences can be accommodated.
What is an underfloor plenum?
An underfloor plenum is the open space between a structural concrete slab and the underside of a raised access floor system. Commonly used as the service plenum for distributing power, voice, and data cabling, in UFAD systems supply air is also delivered through this space.
What is overhead air distribution system?
Overhead air systems are generally considered to be mixing ventilation systems, designed to mix the entire air supply volume within an enclosed space at a specified temperature set point. Therefore, the air must be heated or chilled accordingly to ensure the entire air volume is maintained at that temperature.
What are the three types of ventilation?
There are three methods that may be used to ventilate a building: natural, mechanical and hybrid (mixed-mode) ventilation.
What are the types of air distribution system used in mechanical ventilation for an enclosed area?
There are three types of whole-house mechanical ventilation systems: exhaust-only, supply-only, and balanced. Each system uses a combination of fans, ducting, dampers and controls, and they each have different pros, cons, and costs accompanying them.
What is chilled beam in HVAC?
A chilled beam is an air recirculation device that uses water to transfer sensible heat to and from a room. It is made of convective coils that are placed in the ceiling of a thermal zone to provide sensible cooling and/or heating. Chilled Beams can be “two-pipe” (cooling only) or “four-pipe” (heating and cooling).
What do you mean by underfloor air distribution?
Underfloor air distribution. Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings as part of the design of a HVAC system.
How does an underfloor air conditioning system work?
Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings as part of the design of a HVAC system. UFAD systems use an underfloor supply plenum located between the structural concrete slab and a raised floor system to supply conditioned air…
Where is the underfloor air supply plenum located?
UFAD systems use an underfloor supply plenum located between the structural concrete slab and a raised floor system to supply conditioned air through floor diffusers directly into the occupied zone of the building.
How is heat transfer through the UFAD system?
Heat transfer pathways in UFAD system. Plenum supply air temperature rise is the increase of the conditioned air due to convective heat gain as it travels through the underfloor supply plenum from the plenum inlet to the floor diffusers. This phenomenon is also named thermal decay.