PM2.5 (XH) fresh air ventilator

PM2.5 (XH) fresh air ventilators are divided into ceiling mounted, vertical, and horizontal installation methods. Central Air Conditioning Home can also design and produce non-standard products according to user needs to meet the needs of customers and the market to the greatest extent possible.

The PM2.5 (XH) fresh air ventilator produced by Central Air Conditioning Home adopts a plate fin heat exchanger, which is a type of static heat exchanger that directly exchanges air with air. It does not require heat exchange through an intermediate medium and does not have a rotating system. Therefore, a static plate fin heat exchanger (also known as a fixed heat exchanger) is an ideal energy recovery device. Static plate fin heat exchanger is used for sensible or total heat recovery when there is a temperature difference and water vapor partial pressure difference between the two airflows on both sides of its baffle.

In a plate fin heat exchanger, two airflows flow through the heat exchanger in a cross shape. The partition of sensible heat exchanger is made of non permeable material with good thermal conductivity, usually aluminum material. A total heat exchanger is a type of permeable air air heat exchanger, in which the partition is made of treated materials with good heat and moisture transfer properties. The exchange mechanism of temperature (sensible heat) is that when air of different temperatures flows through both sides of the medium, heat is exchanged through conduction. The exchange of humidity (latent heat) in a total heat exchanger occurs through the following two mechanisms:

① Moisture exchange is carried out through the differential pressure of water vapor on both sides of the medium.

② The water vapor on the high humidity side is absorbed by the moisture absorbent and released towards the low humidity side through the capillary action of paper fibers.

Plate fin heat recovery device:

A、 Static heat exchanger, in order to facilitate the arrangement of airflow channels inside the machine and reduce the volume of the whole machine, small and medium-sized fresh air ventilators adopt a flat cross static heat exchanger. Its working principle is that the movement directions of cold and hot air are perpendicular to each other, and the airflow inside the heat exchanger belongs to the convective heat transfer property in the turbulent boundary layer, with high heat exchange efficiency.

B、 Sensible heat exchanger and total heat exchanger, sensible heat exchanger is made of aluminum foil material, with high temperature conductivity and long service life, suitable for areas with large indoor and outdoor temperature and small humidity differences. The total heat exchanger is made of paper made from specialized fibers using a special process. This material has the characteristics of high moisture permeability, good air tightness, tear resistance, and aging resistance. A total heat exchanger is suitable for areas with small temperature and large humidity differences indoors and outdoors.

Conversion of PM2.5 (XH) fresh air ventilator parameters

A certain computer room has an area of S=65 square meters, a net height of 3 meters, and n=25 personnel. If calculated based on the required fresh air volume per person, taking the required fresh air volume q=30m3/h per person, the total fresh air volume Q1=n × q=25 × 30=750m3/h; If calculated based on the fresh air exchange rate of the room, taking the fresh air exchange rate p=4 times/h, then the fresh air volume Q2=p.s.h=4 × 65 × 3=780m3/h; Due to Q2 being greater than Q1, Q2 is chosen as the basis for equipment selection; Based on the product model, our company's XH-80D full heat exchange product can be selected.

Note: The formula for calculating room volume is: volume=length x width x height below the air supply outlet

The number of fresh air ventilators to be selected is equal to the room volume multiplied by the required number of air changes divided by the rated fresh air volume of a single fresh air ventilator

Design Considerations

1. To ensure smooth convection in the environment, the system exhaust air volume is equal to the fresh air volume.

2. Building space volume size: The breathing activity zone of the occupants in the living room is 2.4m in vertical height; The respiratory activity zone of people in commercial buildings has a vertical height of 4.5 meters, and the volume ratio of the respiratory zone to the entire space is approximately 0.26-0.47

3. The fresh air volume of residential and office buildings shall not be less than 30m3/h.p. Taking into account both the number of air changes and the minimum fresh air volume, calculate the maximum fresh air volume based on both factors as the selection criteria.

4. Sports venues, conference halls, cinemas, etc. can determine the selection of fresh air volume based on the occupancy rate and air exchange rate. For people staying for less than 3 hours, the fresh air volume will be determined based on a 50% occupancy rate.

5. For large shopping malls and other shared spaces with central air conditioning systems, the selection of fresh air volume is determined based on 30% of the central air conditioning system's supply air volume.

Design requirements for air ducts

1. To achieve the lowest wind resistance and noise in the designed air duct, mufflers or canvas soft connections are used between the fresh air outlet and the main unit, and between the exhaust outlet and the main unit.

2. For suspended ceiling machines, spring dampers or rubber dampers must be installed on the suspension rods.

3. When concealed indoor lifting, maintenance and inspection openings must be reserved.

4. The main engine and main air duct should maintain a 3-5 ℃ angle, and the position of the main engine should be kept slightly higher.

5. Metal air ducts must be insulated.

6. PVC pipes, rubber corrugated pipes, aluminum foil asbestos pipes, and aluminum foil composite pipes have their own insulation properties and can be directly installed and used.

7. Installation of air valve: An air volume regulating valve must be installed at the junction of the main air duct and the branch air duct at the proximal and distal ends. Air flow deflectors or air volume regulating valves can be used in the middle of the pipeline system.

8. Air ducts should be connected with flanges, and rubber sealing strips should be added to the connecting flanges.

9. Choose the position for opening the air outlet: The opening of the air outlet should be uniform in principle to ensure a balance between the fresh air volume and exhaust air volume in various parts of the room.

10. The air outlet should not be opened at the following positions: the turning point of the air duct, the tail of the air duct, or the changing diameter of the air duct.

Additional explanation: With the continuous improvement of our company's technical level, we reserve the right to make changes to product parameters without prior notice.