What Are the Differences Between Air Speed, Air Volume, and Air Pressure?

Sometimes, people comment on an air conditioner that it has high air volume but it's not cold, or it operates loudly but the room temperature decreases slowly, or the air speed is strong but there is no feeling in a distant place.

Behind these experiences, they are related to three conceptions that are easily confused: air speed, air volume, and air pressure. They are at different levels but determine the comfort, air supply distance, and cooling performance at the same time.

I. What is air speed? -- the wind that you had experienced

Air speed is the velocity of the airflow with the common unit of m/s (meters per second). To put it simply, air speed determines how strong the wind blows on your face when you stand in front of the air outlet.

The higher the air speed, the more significant the feeling of airflow; and the lower the air speed, the smoother the airflow would be. In the air conditioning, a high air speed does not mean quicker cooling; instead, it will form a feeling of direct air flow and produce noise and discomfort.

II. What is air volume? -- the key to determine the cooling efficiency

Air volume refers to the volume of the supplied air in the unit time with a unit of m³/h or ft³/h (cubic meters per hour, cubic feet per hour). To put it simply, air volume determines how much of the air has been processed and joined in the cooling circle.

The higher the air volume, the quicker the air circulation inside, and the more even the overall temperature will be; on the contrary, the lower the air volume, the less even the temperature will be.

III. What is air pressure? -- the ability to supply the air to a distance

Air pressure, or static pressure, refers to the ability of the system to overcome the resistance; the unit is Pa. Simply, it determines whether the air would spread to a long distance and across the obstacles with stability.

Air pressure is the key index to the central air conditioners and ducted air conditioners. Insufficient pressure will make the air strong near the vent but weak while far from the vent, and the longer the vent, the worse the cooling performance will be. Sufficient air pressure will provide an even air volume at every vent and supply air stably in the large spaces.

IV. The relationship between them is not "the bigger the better" but a match

There is a common misconception that the stronger the air blow, the better the air conditioner will be. In fact, high air speed with small air volume and low air pressure will only make it cool around the air outlet. Reasonable air speed with high air volume and enough air pressure will make the whole room have an even and comfortable temperature.

V. Reasons why our air conditioner is not comfortable

1. Large room with small air volume: the cooling process is slow and the temperature difference is large.

2. Inadequate static pressure: for the ducted air conditioners, this situation will lead to no wind at the air outlet.

3. Force to increase the air speed: the higher the wind, the louder the noise, and the easier it is to get a headache.

VI. How to choose among these parameters?

· Wall mounted air conditioner/floor standing air conditioner

Focus on whether the air volume matches with the room size. The wind needs to be smooth instead of being strong.

· Ceiling cassette air conditioner/ducted air conditioner/central air conditioner

The air pressure is the key point. Models with multiple vents and long pipes should come with high static features.

· Inverter air conditioners

Inverter models are ideal options for various spaces; they can adjust the load automatically, saving energy and providing comfort.

We are professional air conditioner manufacturers. For more information on specifications of the air conditioners, please feel free to contact us!