Principle: Underfloor AirDistribution System (UFAD system), the cold air is sent out through the ground diffuser and returned at the ceiling, and the comprehensive airflow pattern from the ground to the ceiling is formed by the air flow driven by buoyancy, and effectively removes the residual heat of the adjusted space.
The floor air supply system supplies air from the lower space of the floor, the air supply temperature is high (generally 17~18 °C) when cooling, different local climate environments can be formed in the same large space, and the indoor air flow distribution is the downward and upward return air flow mode from the floor to the ceiling.
Features of floor air supply:
(1) Improve thermal comfort
Allow individual indoor personnel to control the local thermal environment and improve thermal comfort;
The increase or decrease of the heat load has little effect on the change of the work area.
(2) Improve ventilation efficiency and indoor air quality
Air exchange efficiency: 50% for hybrid type, 50%-100% for downward air supply.
Ventilation efficiency: 100% ≤ mixed type, only 50%-70% in reality, 100% ≥ downward air supply, usually 100%-200%.
(3) Reduce energy consumption
Compared with the top air supply, the air supply temperature is higher (16~18%) during cooling, which can reduce energy use, and the downward air supply can save energy by 25%-50% (small load; simple construction and installation; high efficiency of the refrigerator; easy to use natural energy in the transition season).
(4) The life cycle cost of the building is less
The reduced size of air handling equipment and ducts saves installation space, which in turn reduces the floor height of the building and reduces the cost.
(5) Reduce the floor height of the building
(6) Easy to construct and install, easy to clean
The location of the tuyere can adapt to changes in room layout, decoration, and use;
Convenient access/exit of cables and devices;
There is no spatial contradiction with other pipelines;
There is no requirement for the height of the ceiling;
The decoration is easy to match with the building;
No pipes through the construction trouble;
No condensation and leakage of water to the office facilities and decoration;
No maintenance inconvenience, etc.
(7) Cons
a. Wind sense problem: the distance from the air outlet to the person when the lower air supply is closer than that when the upper air is supplied, and the attenuation distance of the air flow blown out is short, which is easy to cause wind feeling.
b. Dust problem: When the air is supplied downward, the wind blows out from the bottom to the top, and if it is not properly handled, it will blow up the fine dust on the ground, so that the indoor air quality will not be improved but deteriorated.
Floor diffuser form:
Examples of floor air supply design projects:
This article comes from the Internet.