JPH03191227A - Air filter clogged state displaying device for fan coil device - Google Patents

Abstract

PURPOSE:To enable a clogging of an air filter to be detected less expensively with a simple fixing structure by a method wherein air speed sensors having a characteristic for varying an amount of thermal radiation in response to an air speed are arranged across an air filter and a clogged state of the air filter is discriminated by an air speed level sensing means. CONSTITUTION:A removable air filter 12 is arranged in a suction duct 11. An air blower 4 is operated and air speed sensors 20 and 21 are arranged at an upstream side and a downstream side of the air filter 12, respectively. The air speed sensors 20 and 21 are integrally shielded with a heater and a temperature sensor. The temperature sensor is heated by a specified amount with the heater and kept at its high temperature state. A radiation heat amount for a surrounding atmosphere is varied in response to an air speed level passing trough the suction duct 11 and then an air speed level is detected. Its temperature characteristic is decreased in response to the air speed level corresponding to the clogged state of the air filter 12 and as an aeration in the suction duct 11 is decreased due to the clogging state, the air speed levels in the air speed sensors 20 and 21 are inputted into the clogged state discriminating means 23 through the air speed level sensing means 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air conditioner installed in a ceiling, more specifically, to an air filter clogging detection device installed in a suction duct of a fan coil unit or the like. It is something.

2. Description of the Related Art Conventionally, a fan coil unit installed mainly in the attic of a building has a structure as shown in FIG.

That is, the main body 3 of the fan coil unit installed in the attic 2 of the ceiling 1 includes a blower 4 for indoor circulation and a heat exchanger 6 for passing cold and hot water, and is located on the indoor e side from the main body 3. air outlet duct connected to the air outlet 8 opened in the wall surface 7)
9 and a suction duct 11 connected to a suction port 10 opened in the ceiling 1 are connected to the main body 3, respectively. The suction duct 11 is provided with a removable air filter 12 near the main body 3, and an upwind pressure sensor 13 and a leeward pressure sensor are installed on the windward side and the leeward side of the air filter 12, respectively, to detect wind pressure. It is equipped with 14.

By the windward pressure sensor 13 and the leeward pressure sensor 14,
a detection means 15 for detecting the respective pressure levels, a comparison means 16 for comparing the pressures of the upwind pressure sensor 13 and the leeward pressure sensor 14 from this detection means 15, and this comparison means 1.
clogging determination means 17 for determining the clogging state of the air filter 120, and the clogging determination means 17 outputs it to the operation control unit 19 provided on the wall surface 7 via the display means 18. , when a predetermined level of clogging is reached, a display is displayed on the operation section 19.

Problems to be Solved by the Invention In such a conventional configuration, an expensive upwind pressure sensor 13 with high accuracy is used to measure and detect clogging of the air fill 12.
The pressure sensor 14 and the downwind pressure sensor 14 are required, and are installed inside the suction duct 11, which is cylindrical or rectangular.
2 and 13 occur, it is necessary to consider how to fix the same pressure sensors 12 and 13 in the suction duct 11, and the control circuit up to the operation control section 19 becomes complicated. Ta.

The present invention solves the above-mentioned conventional problems and is easy to install.
The purpose of this configuration is to provide inexpensive measurement and detection of air filter clogging.

Means for Solving the Problems In order to solve this problem, the present invention includes a suction duct connecting the main body of a fan coil unit and a suction port, and a blow-off duct connecting the main body and a blow-off port. An air filter is provided in the suction duct, and wind speed sensors having a characteristic that the amount of heat dissipated changes depending on the wind speed are provided before and after the air filter, and a wind speed level detection means for detecting the wind speed from the wind speed sensor, and a wind speed level detection means for detecting the wind speed level are provided. clogging determination means for determining whether the air filter is clogged; output from the clogging determination means; when a certain level of clogging has been reached, the output is output to a display means; The configuration is such that the output is output to indicate clogging.

With this configuration, the wind speed sensors provided before and after the air filter output the wind speed level in the suction duct to the wind speed level detection means, and from this wind speed level detection means, the clogging state is determined by the clogging judgment means. This is outputted to the operating unit via the display means, and the clogging state of the air fill is displayed on the operating unit.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3. Note that the same reference numerals as explained in the conventional example indicate the same parts, and the explanation thereof will be omitted. That is, a removable air filter 12 is provided in the suction duct 11, and by operating the blower 4, wind speed sensors 20, 21 are provided on the windward side and the leeward side of the air filter 12, respectively. These wind speed sensors 20 and 21 are heaters and temperature sensors! 5 one piece K
It has a shield configuration, and the temperature sensor is heated to a certain amount by a heater to a high temperature, and the amount of heat radiated to the surroundings changes depending on the wind speed level passing through the suction duct 11, and the wind speed level is detected. That is, the wind speed sensor 2
0 and 21 have the characteristic that by applying an air flow, the temperature level of the temperature sensor that is heated by a certain amount decreases depending on the wind speed level, and this characteristic is determined by the wind speed and output as shown in Figure 2. This diagram shows the correlation with voltage, and has the characteristic that the output voltage decreases as the wind speed decreases. Figure 3 shows the circuit configuration to obtain the characteristics shown in Figure 2. A wind speed level detection means 22 that detects the wind speed level, a clogging 9 judgment means 23 that reads the wind speed level from the wind speed level detection means 22, and a clogging judgment means 2.
3, when one or both of the wind speed levels decrease by a certain amount, the output is output to the display means 18, and the display means 18 outputs the output to the operation operation section 19 for display, and the air filter 12
This is to notify you that the air conditioner is clogged.

In the above configuration, the blower 4 is operated to suck indoor air through the suction port 10 while passing cold water or hot water through the heat exchanger 6, and the air filter 1 provided in the suction duct 11 is
2, the dust is removed while passing through the air blower 4, and then the heat exchanger 6.
The cooled air or warm air passes through the air outlet 8 through the air outlet duct 9.
The air is blown out for cooling or heating. During this circulation, the wind speed sensors 20 and 21 are heated by a shielded heater to a high temperature, and then
Depending on the wind speed level corresponding to the clogging state of the air filter 12, its temperature characteristics decrease, and when the airflow in the suction duct 11 decreases by a certain amount due to the clogging, the wind speed of each wind speed sensor 20 and 21 decreases. The level is taken into the clogging judgment means 23 via the wind speed level detection means 22, and if one or both of the wind speed levels decrease by a certain amount,
This is displayed on the operation unit 19 via the display means 18 to indicate that the air filter 120 is clogged.

In addition, in FIG. 2 of this embodiment, the temperature sensor used for the wind speed sensor showed the characteristic that the higher the temperature, the lower the resistance characteristic of the temperature sensor, but the opposite characteristic, that is, the higher the temperature, the lower the resistance characteristic A similar effect can be obtained when a temperature sensor with improved characteristics is used. Further, in FIG. 3, even if the connection between the wind speed sensor and the fixed resistor is reversed, the same effect can be obtained.

Effects of the Invention As is clear from the description of the embodiments described above, the present invention provides an air filter in the suction duct of a fan coil unit equipped with an air blower and a heat exchanger, and provides air filters on the windward and leeward sides near the air filter. A wind speed sensor composed of a heater and a temperature sensor is provided in each of the wind speed sensors, and when the wind speed level decreases by a certain amount by one or both of the wind speed sensors, the wind speed level is captured by the wind speed level detection means to the clogging determination means, and the display means displays the information. Since the information is displayed on the operation unit via the air filter, it is possible to determine the clogging state of the air filter and display the clogging state. In addition, by independently detecting the two wind speed sensors, there is no need for highly accurate comparison means such as pressure sensors, and the need for complicated control means can be reduced.Moreover, the shape of the suction duct changes in the vicinity of the air filter installation. There are relatively few restrictions on installing the air filter so that there is no difference in the amount of decrease in the wind speed level before and after the air filter due to clogging or bending. Further, conventional pressure sensors are relatively expensive and are greatly affected by minute vibrations, but wind speed sensors are inexpensive and have the advantage of not being affected by vibrations as much.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of an air filter clogging display device for a fan coil unit according to an embodiment of the present invention, Fig. 2 is a characteristic diagram of a wind speed sensor, Fig. 3 is a characteristic detection circuit diagram of the wind speed sensor, and Fig. 4 1 is a configuration diagram of a conventional fan coil unit air filter clogging display device FIT. 3... Main body, 8... Air outlet, 9...
...Blowout duct, 10...Suction port, 11...
...Suction duct, 12...Air filter, 18...Display means, 1e...Operation unit, 20.2'1...Wind speed Sensor, 22...
. . . Wind speed level detection means, 23 . . . Clogging judgment means.

Claims (1)

[Claims] The fan coil unit includes a suction duct that connects the main body and the suction port, and an air outlet duct that connects the main body and the air outlet. A wind speed level detecting means for detecting wind speed by each wind speed sensor having a characteristic that the amount of heat changes; and a clogging determining means for determining the clogging state of the air filter based on the output from the wind speed level detecting means. This is output from the clogging determining means, and when a certain level of clogging is reached, it is output to the display means, and the display means outputs the output to the operation control unit to display the air filter clogging of the fan coil unit. .