Is it okay if the guest room has only ventilation and no fresh air?

For hotel rooms, no matter which way is adopted, the wind speed of the air duct is generally small (generally, the sound pressure level of allowable noise in high-star hotel rooms is ≤35dB(A), and the maximum wind speed of the air duct in the corresponding system of the main pipe and branch pipe is ≤ 6m/s; Branch pipe without tuyere ≤ 5m/s; Branch pipes with air supply and exhaust outlets ≤3m/s). For the convenience of construction, the cross-sectional dimensions of fresh air branch pipes in all standard rooms are the same. Due to the low wind speed of the branch pipes, the resistance of each branch pipe in the room is very small. If the distance between the terminal branch pipe and the farthest branch pipe is relatively long, the pressure loss between the distal branch pipe and the proximal branch pipe is very different. Therefore, it is necessary to adopt relevant adjustment means to ensure the balance of pipeline pressure loss. Generally, valve adjustment is used to increase the resistance of branch pipes with small pressure drop. Adjust the fresh air volume of each branch pipe, and at the same time, in order to control the initial investment, the selected valve is usually a quick-opening single-plate butterfly valve, and its adjustment function is very limited. Therefore, even if the regulating valve is set, the air volume at the beginning and the end is still quite different, so when arranging the fresh air system, the system should not be too large (high-star hotels can use constant air volume valves); The general fresh air system is as follows:

1) The fresh air machine room is designed independently on each floor. After being filtered, cooled (heated) and humidified, outdoor fresh air is sent to each room from the horizontal direction along the ceiling of the corridor. This method has the following advantages: because the fresh air room is designed separately on each floor, the system operation and adjustment are more convenient; There is no fresh air riser between adjacent rooms, which saves the shaft area and has a large layout space of the bathroom. Its disadvantages are: first, the adjacent rooms of the fresh air machine room will be affected by noise, which will lead to lower operating price; Secondly, the horizontal arrangement of fresh air duct in the corridor of guest room floor will greatly reduce the clear height of corridor and lead to the sense of oppression of guests; Third, it is also the most taboo thing. Maintenance personnel in the hotel engineering department often appear in the guest room corridor, disturbing the privacy of guests. (For the design principle of the electromechanical system in the guest room area of a high-class hotel: "People (guests) come first", firstly, ensure that the electromechanical system must be maintained to the maximum extent, and minimize the interference to the guests; Secondly, ensure the comfort and difference of power supply, water supply and air conditioning to the maximum extent. ), this method is suitable for hotels under 4 stars.

2) Unified design of fresh air machine room on the roof or technical floor. A fresh air shaft is designed between adjacent rooms, and fresh air is sent from the fresh air room to each room through the shaft. This method has the following advantages: there is no need to design a fresh air room on the guest room floor, and the maintenance of the fresh air room will not affect the guests; Because the fresh air duct is vertically arranged, there is no fresh air duct in the corridor ceiling, which is beneficial to the layout and elevation of the ceiling; The fresh air machine room and the exhaust fan of the bathroom are arranged on the same floor, which is beneficial to the design of heat recovery system between exhaust air and fresh air. Its disadvantage is that the fresh air shaft is designed between adjacent rooms, and the shaft area near the bathroom is large, which is not conducive to the layout of the bathroom. This method is more suitable for hotels with 4 stars and above.

For room ventilation practice, there are the following specific requirements:

1) ceiling exhaust fan; Directly installed on the ceiling between shower room or bathtub and toilet. The ceiling exhaust fan is noisy, and improper installation will make the ceiling of the ceiling vibrate together and make noise. Five-star hotel decoration requires that the exhaust fan can't be seen on the ceiling of the bathroom. For noise reasons, it is not suitable to use the exhaust fan, which is suitable for hotels below 4 stars.

2)① Design a silent exhaust fan (duct fan) in the ceiling; One or two strip vents are arranged above the shower room or bathtub or toilet, and the vents are hidden; The outlet of the fan is equipped with a check valve (or with its own check valve). In order to avoid crosstalk between rooms, a pipe muffler should be installed on the air duct connected to the air outlet (GBJ 87-85 Code for Design of Noise Control in Industrial Enterprises 5.3.3, when the pipe diameter is not more than 400mm, a straight pipe muffler can be selected); 900mm dragon per section; ) or muffler elbow. (2) There is no exhaust fan in the bathroom, and the exhaust fan installed on the roof is used for unified exhaust, and the exhaust branch pipe in the bathroom is provided with an air volume valve. The two exhaust modes have their own advantages and disadvantages. The first mode can easily solve the problem of air balance between different floors, but attention should be paid to the noise problem when choosing fans. Because the exhaust fan is installed in the ceiling, the maintenance work in the ceiling is larger than that in the latter. (2) Because there is only a constant air volume valve in the ceiling, it is easier to solve the noise problem in the bathroom, and it is necessary to balance the air volume of the system, but the cost is higher. This method is more suitable for hotels with 4 stars and above.

3) Selection of main exhaust fan

The sum of the air volume of each branch pipe, when the bathroom is equipped with exhaust fan or pipe fan, consider 0.7~0.9, and use the system at the same time; The main exhaust fan is controlled by frequency conversion and speed regulation (or the time control switch is equipped with two exhaust fans, and the rooms are generally at 6: 00 ~ 9: 00 and 17: 00 ~ 20: 00, and the opening rate is high. At the same time, two exhaust fans are turned on to exhaust air, and one exhaust fan is turned on at other times. The specific setting value must be determined according to the operation of the hotel).