The object of the present invention is to provide a supply air device, which is composed of a body part having a connection to outdoor air through an outdoor air duct, and which supply air device contains a fan, which blows outdoor air into the room space, and which supply air device includes a return air control system for said room space.

Supply air device according to the present invention is used in residential and busi- ness buildings to direct outdoor air into the room spaces.

Hitherto outdoor air has been directed into the room spaces through a supply air vent with an electrical heater or without any heater. One alternative is a central air- conditioning system, wherein supply air is distributed into the room spaces.

Supply air vent equipped with a heater consumes a lot of electricity. On the other hand, a vent without a heater causes draught and central air-conditioning system is expensive. Finnish utility model No 8413 describes a supply air device known perse. By means of this device the above-described problems can be avoided.

The object of the present invention is to provide a supply air device model, which is new and parallel compared with the supply air device presented in the utili- ty model 841 3. Supply air device of the present invention is characterized in that the control system is composed of heig ht-adjustable legs in between the body part and wall .

Different embodiments of the present invention have been defined in the appended dependent claims.

Next the invention is described by an example with reference to the accompanying drawings, wherein: Figure 1 illustrates a supply air device installed on the wall, and

Figure 2 is a sectional view of slats in a lattice of the air supply device. Supply air device consists of a body part 1 , h a v i n g a connection to outdoor air through an outdoor air duct 2, and which supply air device contains a fan 3, which blows outdoor air 4 into the room space, and which supply air device includes a return air control system for said room space. Said control system is composed of the height-adjustable legs 6 in between the body part 1 and wall 5. Said height-adjustable legs 6 are plug tabs. Outdoor air d uct 2 includes a filter 7.

Body part of the supply air device includes an attached lattice 10 having horizontal slats 1 1 , which have grooved cross-section. Thus, supply air entering into the room is directed askewly upwards and at the same time causes turbulence with the air already in the room space. In cross-sectional view the slat 11 has a profile of an obtuse angle, wherein the other leg A is a solid part of the lattice and has a height of 2 - 5 mm, and from which an air deflector slat B, the width of which is 10 - 16 mm, extends at an angle of about 45°. The slit C between the slats 11 is 8 - 12 mm.

Installation of the supply air device.

The device is installed in a dry warm room space on the external wall 5 at least 1.8 m up from the floor. The distance between the ceiling and the top edge of the device is at least 200 mm. A slightly outwardly inclined outdoor air duct 2 is installed into a hole bored through external wall 5. An outdoor lattice 8 will be attached to the open-air side of the outdoor air duct 2. Said outdoor air duct includes a filter 7. Outdoor air duct 2 will be cut onto the lining of the wall 5 and sealed into the wall structure. A clamping frame (not presented in the application) will be installed around the outdoor air duct located on the lining of the wall. The device is attached to the clamping frame, and then equipped with a power cord and connected to a wall plug. Thereafter the device is ready for use.

Use of the supply air device.

Rear body part of the device includes three plug tabs, which serve as height- adjustable legs 6, by which the distance of the device 1 from the wall 5 can be adjusted. Heating of outdoor air 4 is based on use of the return air, i.e. when the fan 3 is on, outdoor air will flow into the duct and warm room air 9 will flow into the duct through a slot between the device and wall. Thus, outdoor air will be warmed by the aid of room air. Depending on the level of negative pressure of the room, plug tabs 6 can be adjusted so, that the vent extends 5 - 15 mm from the wall. Standard setting is 10 mm, which operates well in normal circumstances. Especially during winter time it is recommended to use as fast fan speed as possible to provide enough warm room air to heat incoming outdoor air 4. During summer time, if incoming air is preferred to be taken only from outside, height- adjustable legs 6 can be adjusted to position 0, wherein the device will be tightened against the wall lining 5. As an additional feature, the device can also be used as an extraction fan, wherein the blowing direction of the fan is reversed.