Patent Description:
The most popular mode of ventilation in buildings, e.g. apartment buildings, from <NUM> to <NUM> has been mechanical exhaust ventilation.

In the mechanical exhaust ventilation system of apartment buildings, it is by means of an exhaust air blower fitted in connection with an exhaust air duct that indoor air is discharged by way of apartment-specific exhaust air valves into the exhaust air duct along which the air removed from interior spaces is then conveyed to the apartment building's roof.

As the exhaust air blower is removing air from apartments, the latter develop a negative pressure, it being by virtue of the negative pressure that the fresh make-up air, replacing the air that is being removed, enters the apartments either in a controlled manner by way of fresh air valves or in an uncontrolled manner through the apartment building's structures.

The exhaust air blowers operate usually at two speeds and with timer control. Thus, the timer-controlled exhaust air blower is working at half or full capacity depending on the assessed utilization rate of an apartment building.

Document <CIT> discloses an exhaust-air blower and exhaust-air system of a building. Document <CIT> discloses an automatic exhaust fan control apparatus and method.

One objective of the invention is to solve problems of the prior art and to provide a retrofittable exhaust air blower controller, enabling an old exhaust air blower to be converted into a smart exhaust air blower. It is by virtue of intelligence added to an exhaust air blower that the exhaust air blower enables implementation of need-adapted ventilation on the basis of measurement data indicated by sensors, thereby preventing e.g. the ventilation-induced loss of heat energy, improving the comfort of living, enhancing safety in apartments, eliminating the feeling of draft from apartments, enabling nocturnal summertime ventilations in apartments, improving fire safety and eliminating the mechanical sounds of exhaust air fans.

One objective of the invention is attained with a retrofittable exhaust air blower controller, a control method, and a computer program product according to the independent claims.

The retrofittable controller according to one embodiment for a building's exhaust air blower comprises a processor unit, a data transfer unit, and a memory unit. The controller further comprises a sensor unit, comprising at least one sensor for measuring the exhaust air arriving at the exhaust air blower, and a control unit which is adapted to regulate operation of a fan motor on the basis of a measurement conducted by at least one sensor. The controller further comprises a protective housing inside which the controller's units are installed, and an attachment element for fastening the controller to a safety cage of the exhaust air blower. The protective housing comprises an air inlet duct, which protrudes therefrom and is intended to be fitted inside the exhaust air blower's safety cage, and by means of which a portion of the exhaust air arriving at the exhaust air blower is conducted into the protective housing to be analyzed by the sensor unit.

The control method according to one embodiment for a building's exhaust air blower is implemented with a controller according to the previous embodiment. The method comprises a step of measuring, with at least one sensor of a sensor unit (<NUM>), the exhaust air arriving at the exhaust air blower. The method further comprises a step of regulating, with a control unit, the operation of a controller-coupled fan motor of the exhaust air blower on the basis of a measurement conducted by at least one sensor.

The computer program product according to one embodiment intended for controlling a building's exhaust air blower comprises instructions which enable a computer to execute steps of the method according to the previous embodiment as the program is run on the computer.

Other embodiments are presented in the dependent claims.

Exemplary embodiments of the invention will now be described more precisely with reference to the accompanying figures:.

<FIG> shows an exhaust air blower (roof extractor) <NUM>, which is capable of being fitted in a ventilation pipe for the exhaust air duct of a building <NUM>, e.g. an apartment building or a row house, and which is updated for smartness by retrofitting it with a controller (control unit) <NUM> for a fan motor <NUM>.

The exhaust air blower <NUM> is mounted on the end of an exhaust air duct extended from interior spaces of the building <NUM> up to its roof, whereby the removable air leaves the building <NUM> by way of the exhaust air blower <NUM>.

The exhaust air blower <NUM> has a safety cage (outlet diffuser) <NUM> with a function of protecting components <NUM> therein from the effect of weather and mechanical impacts. The safety cage <NUM> is fabricated from thin sheet metal whose material is e.g. aluminum and/or steel.

The safety cage <NUM> comprises side members <NUM>, a bottom plate attached to the lower part thereof and provided with a penetration hole for a ventilation pipe, and a lid <NUM>.

In an exhaust air blower <NUM> as shown in the figure, the exhaust air discharges from the safety cage by way of air vents <NUM> in the side members <NUM> as well as by way of a gap between a top edge of the side members <NUM> and the lid <NUM>. There are also other types of options for conducting exhaust air out of the exhaust air blower <NUM>, depending on the type of blower.

<FIG> shows more precisely the controller <NUM>, which is mounted e.g. on an external surface of any side member <NUM> of the safety cage <NUM> as shown in the figure. On a bottom right-hand edge of the figure, the controller <NUM> is shown in a view from the direction of a rear surface <NUM>, on a top right-hand edge from the direction of a bottom <NUM>, and on a bottom left-hand edge from the direction of the right side. On a top left-hand edge is shown an air inlet duct <NUM> in a cross-section F-F'.

The controller <NUM> is provided with a protective housing <NUM> with a function of protecting the controller's <NUM> units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> from the effects of weather and dirt as well as from mechanical impacts. Fabrication material for the protective housing <NUM> comprises e.g. plastic or steel.

The protective housing <NUM> comprises (includes) an attachment element <NUM> by means of which the controller <NUM> is fastened to the safety cage <NUM>. The attachment element <NUM> is made up e.g. by edge strips <NUM> provided along the sides of the protective housing <NUM>, the attachment made therethrough being used for fastening the protective housing <NUM> to the safety cage <NUM>.

The protective housing <NUM> comprises an air inlet duct <NUM>, which is provided on its rear surface <NUM> intended to be set against the safety cage <NUM>, and which is protruding and intended to be fitted inside the safety cage <NUM>, and for which the safety cage <NUM> must be formed with a sufficiently large opening (not shown) for inserting the air inlet duct <NUM> into an interior of the safety cage <NUM>. It is by means of the air inlet duct <NUM> that a portion of the exhaust air arriving at the exhaust air blower <NUM> is directed into an interior of the protective housing <NUM> of the controller <NUM>, where the sensors of the sensor unit <NUM> are able to conduct measurements thereof and, on the basis of measurement results, to analyze, based on the value and behavior of a measured quantity, the effect thereof on a demand of control for the fan motor <NUM>.

The air inlet duct <NUM> is a hollow, e.g. tubular, rectangular or polygonal passage whose bottom surface <NUM> comprises an air intake <NUM>, by way of which the analysis-bound exhaust air, to be obtained (captured) from an exhaust air flow, is capable of being directed into the air inlet duct <NUM> and along the same into an interior of the protective housing <NUM>. The protective housing <NUM> has a discharge outlet <NUM>, e.g. in a bottom <NUM> of the protective housing, for removing the analyzed air from inside the protective housing <NUM>.

The air inlet duct <NUM> is split with a dividing element (divider) <NUM> in such a way that the air inlet duct <NUM> has its lower part, on the side of the air intake <NUM>, making up an air inlet section <NUM> intended for conveying the analysis-bound exhaust air into an interior of the protective housing <NUM>. On the other hand, the air inlet duct <NUM> has its upper part making up a cable section <NUM> for extending into an interior of the safety cage <NUM> at least a connection cable (control cable) <NUM> for controlling the fan motor <NUM>.

It is also possible to extend measuring tubes <NUM>, <NUM> from the installed controller <NUM> along the cable section <NUM>, which tubes are used e.g. in measuring a pressure difference between an inlet chamber and an inlet cone of the exhaust air blower <NUM> and the first of which is placed to measure an intake pressure of the inlet chamber and the second an intake pressure of the inlet cone.

The protective housing <NUM> comprises an opening <NUM>, e.g. in its bottom <NUM>, for extending a voltage supply cable <NUM> for connection out of the controller <NUM>, and e.g. from its side or, as shown in the figure, from its bottom <NUM> protrudes a temperature sensor <NUM>, included in the sensor unit <NUM>, for a measurement of outdoor temperature. The protective housing <NUM> may also have its side or bottom <NUM> provided with a pressure sensor, included in the sensor unit <NUM>, for a measurement of outdoor air pressure.

The controller <NUM> comprises a shielding shell <NUM> attachable to the safety cage <NUM> and mountable on top of the protective housing <NUM> with a function of ensuring the working ability of the controller <NUM> by keeping, contingent on weather conditions, the ambient air sufficiently warm or cool and sufficiently dry, as well as protecting the controller <NUM> covered by the shielding shell <NUM> from the effects of weather and dirt, and from mechanical impacts. Fabrication material for the shielding shell <NUM> comprises e.g. plastic or metal.

The shielding shell <NUM> is made up by edge strips <NUM> provided e.g. along its sides, the attachment made therethrough being used for fastening the shielding shell <NUM> to the safety cage <NUM>.

The shielding shell <NUM> must be installed on the safety cage <NUM> so as to cover the protective housing <NUM> and an opening (not shown) made in the safety cage <NUM> and not concealed by the protective housing <NUM>. It is by way of this opening that a space between the protective housing <NUM> and the shielding shell <NUM> is supplied from inside the exhaust air blower <NUM> with exhaust air which, in hot, cold or damp weather, maintains the surroundings of the controller <NUM> sufficiently cool, warm or dry. The shielding shell <NUM> comprises at least one adjustable air vent (not shown), e.g. in its lower part or bottom <NUM>, for removing, from inside the shielding shell <NUM>, the air flowing between the protective housing <NUM> and the shielding shell <NUM>.

The shielding shell <NUM> has a roofing <NUM> along which water and snow-turned-water trickle away from top of the shielding shell <NUM>.

<FIG> shows the functional units <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> of the exhaust air blower <NUM> and the controller <NUM>.

Inside the safety cage <NUM> of the exhaust air blower <NUM> is installed a fan motor <NUM> with a function of extracting the air to be removed from apartments into an exhaust air duct and along the same, by way of a ventilation pipe fitted in a penetration hole of the exhaust air blower <NUM>, into an interior of the exhaust air blower <NUM> in which the air to be removed is blown by the fan motor <NUM> through the structure of the exhaust air blower <NUM> out of the building <NUM>. The fan motor <NUM> is installed in the middle of a space defined by the structures of the safety cage <NUM>.

It is a function of the controller <NUM> to upgrade the exhaust air blower <NUM> into a smart device by analyzing, on the basis of a measurement conducted by at least one sensor of the sensor unit <NUM> at its disposal, a demand of control for the fan motor <NUM> and, if necessary, to direct a control unit <NUM> to manage operation of the fan motor <NUM>.

Inside the protective housing <NUM> of the controller <NUM> is installed a control unit <NUM>, a sensor unit <NUM> used in assistance of control, and other functional units <NUM>, <NUM>, <NUM>, <NUM>. The control unit <NUM> is coupled with the fan motor <NUM> by way of a connection cable <NUM>.

The control unit <NUM>, intended for managing the fan motor <NUM> present in the protective housing <NUM>, has a function of its control automation to regulate the output power of the fan motor <NUM> in keeping with guidance received thereby.

The sensor unit <NUM> housed in the protective housing <NUM> has at least one sensor, a measurement conducted thereby on exhaust air arriving at the exhaust air blower <NUM> being used as a basis for directing automation of the control unit <NUM> to regulate operation of the fan motor <NUM>. At least one sensor of the sensor unit <NUM> can also be used for conducting measurements on outdoor air surrounding the exhaust air blower <NUM> and the controller <NUM>. The sensor unit <NUM> comprises at least one of the following sensors: a temperature sensor measuring the temperature of exhaust air, a temperature sensor <NUM> measuring the temperature of outdoor air, a humidity sensor measuring the humidity of exhaust air, a sensor measuring the carbon dioxide content of exhaust air, a sensor measuring the VOC gas level of exhaust air, a sensor measuring the pressure of outdoor air, and sensors measuring the intake pressure of exhaust air with measuring tubes <NUM>, <NUM> thereof being extended into an interior of the safety cage <NUM> and measuring date produced thereby also enabling the amount of air to be determined.

The controller <NUM> comprises a processor unit <NUM>, enabling instructions determined by a user or some application program to be executed and data to be processed.

The controller <NUM> further comprises a data transfer unit <NUM>, by means of which the controller <NUM> receives data over a wireless communication link from outside the exhaust air blower <NUM> (controller <NUM>) and transmits data over a wireless connection away from the exhaust air blower <NUM> (controller <NUM>). The data transfer unit <NUM> comprises e.g. a wireless <NUM>/<NUM> network section, by means of which the controller <NUM> communicates with a device external of the exhaust air blower <NUM>.

The controller <NUM> may comprise a physical user interface unit <NUM>, by means of which the user is able to deliver commands and information and/or to receive information. The user interface unit <NUM> is e.g. a communication interface, to which it is possible to connect by means of a connection cable e.g. an external computer, a user interface equipped with a display and keyboard, or a smart device equipped with a touchscreen.

The controller <NUM> further comprises a memory unit <NUM> for filing and storing applications and data. The memory unit <NUM> may comprise at least one memory, e.g. one, two or three memories.

The memory unit <NUM> may comprise a data transfer application <NUM> controlling operation of the data transfer unit <NUM>, a user interface application <NUM> controlling operation of the user interface unit <NUM>, an analyzing application <NUM> intended for processing data coming from the sensor unit <NUM>, and a control application <NUM> intended for controlling the control unit <NUM> which regulates operation of the fan motor <NUM>.

Internal communication required by the controller <NUM> between various units <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is implemented over a fixed cable connection.

The memory unit <NUM> has stored therein predetermined limit values for each quantity to be measured and, when an exceeding of limit value is indicated by measurement data coming from a sensor, the analyzing application <NUM> determines whether operation of the fan motor <NUM> is to be regulated thereby. The limit values determine whether the output power (rotation speed) of the fan motor <NUM> is continued to be maintained the same, whether it is reduced or increased.

Limit values can be preset e.g. for temperature, such that, when the temperature of exhaust air falls to below <NUM>, the control unit <NUM> is directed by the controller <NUM> to reduce output power of the fan motor <NUM> for reducing draft in the building's <NUM> apartments. On the other hand, if the temperature of exhaust air exceeds <NUM>, the control unit <NUM> is directed by the controller <NUM> to increase output power of the fan motor <NUM> for enhancing ventilation and, if the temperature of exhaust air is with the range of <NUM>-<NUM>, the current output power of the fan motor <NUM> will be maintained. The same applies also to other quantities to be measured. In addition, the controller <NUM> is capable of establishing the need of enhancing or reducing ventilation based on measurement data for two or more measured quantities on the basis of preset limit values.

In addition, the analyzing application <NUM> is capable of determining a demand for ventilation on the basis of measurement data for two or more measured quantities. the analyzing application <NUM> is capable of detecting a fire in the building <NUM> from exhaust air by analyzing measurement data coming from VOC, carbon dioxide, temperature and humidity sensors and, based on the analysis, the controller <NUM> directs the control unit <NUM> to enhance operation of the fan motor <NUM> for removing smoke. Moreover, after detecting a fire, the controller <NUM> is able to deliver information thereof in a wireless manner by way of the data transfer unit <NUM>, i.e. to send a fire alarm, to some other external terminal device.

The exhaust air blower <NUM> may have its operation monitored and/or controlled in real time over a wireless connection by means of a terminal device, e.g. a desk or portable computer or a smart phone, using browser-based control software intended for controlling the exhaust air blower <NUM>. By means of the terminal device's control software it is possible to monitor operation of the exhaust air blower <NUM>, or several exhaust air blowers <NUM>, by examining measurement data coming from various sensors of the controller <NUM> and analysis data constructed on the basis thereof, to obtain messages, e.g. a fire alarm, and to control manually operation of the exhaust air blower(s) <NUM>.

<FIG> illustrates the building's <NUM> exhaust air system <NUM>, comprising several exhaust air blowers <NUM> as shown in the preceding figures and updated with the controller <NUM>.

The system <NUM> further comprises a distribution board <NUM>, which is by way of power supply cables <NUM> in communication with each exhaust air blower <NUM>.

Claim 1:
A retrofittable controller (<NUM>) for a building's (<NUM>) exhaust air blower (<NUM>), comprising
a processor unit (<NUM>),
a data transfer unit (<NUM>),
a memory unit (<NUM>),
a sensor unit (<NUM>) comprising at least one sensor adapted to measure exhaust air arriving at the exhaust air blower,
a control unit (<NUM>) adapted to regulate operation of a fan motor (<NUM>) on the basis of a measurement conducted by the at least one sensor,
a protective housing (<NUM>) inside which the controller's units (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) are installed, and
an attachment element (<NUM>) adapted to fasten the controller to a safety cage (<NUM>) of the exhaust air blower,
characterized in that
the protective housing comprises an air inlet duct (<NUM>), which protrudes therefrom and is configured to be fitted inside the exhaust air blower's safety cage (<NUM>) through an opening for inserting the air inlet duct (<NUM>) into an interior of the safety cage (<NUM>) formed to the safety cage (<NUM>), and by means of which a portion of the exhaust air arriving at the exhaust air blower is conducted into the protective housing to be analyzed by the sensor unit.