For treatment rooms and especially for operating rooms, highly refined ventilation and treatment of air is required in comparison with other locations.

This concerns both the amount of ventilated air and the degree of purity of the air. Bacteria-laden particles and contaminating odors present in the room, need to be eliminated effectively. Bacteria and contaminants are likewise prevented from entering the room.

STATE OF THE ART In order to secure correct treatment of air, no reuse or recirculation of air is allowed today. Instead, 100 % new air is continuously supplied. The high requirements placed on air quality in certain types of rooms mean that a comprehensive exchange of air must occur. In an operating room an exchange of the volume of air in the whole room should occur twenty times an hour, according to current norms. An operating room of normal size has a volume of 100 m3, which means that 2000 m3 of new, pure, treated, and temperature-controlled air must be supplied per hour.

With certain climatic conditions the outside air temperature can be 30- 35 °C and the humidity up towards 98 % relative humidity. The volumes of air given above must thus be treated so that the air that is supplied to the

operating room has a temperature of 20-23 °C and relative humidity of 50 %.

An air exchange of this kind entails very high use of energy and associated high costs.

Conventional heat exchangers and similar are available for utilizing energy in the air that is exchanged. In this connection they have low capacity, however. Larger heat exchangers and similar installations with the desired capacity are very expensive to purchase, operate, and maintain.

In countries with cold climates buildings are usually well insulated.

Warm air or warm water is conducted from heating units to various rooms in the building. Losses possibly occurring on the way are used to a great extent anyway through the fact that the energy in any case is utilized within the insulated building.

In countries with warmer climates wholly different building technologies have been used for a long time. An important basic principe in these technologies is to create as much natural ventilation (breeze]) through the building as possible so that heat cannot accumulate. Walls can be furnished with ventilation holes and similar. When new building techniques are introduced and the buildings are made less porous, new problems arise.

An operating room or similar is usually constructed as a separate building with its own simple walls and ceiling inside the larger building.

Between the inner space of the operating room and the surroundings, temperature differences of more than 15 °C can occur. With high relative humidity in the ambient air large amounts of water will condense on the walls and ceiling of the operating room. Water can penetrate into the wall material and create mold problems and similar. Additionally, problems with moisture damage can arise in electrical installations and medical equipment that is located in walls and in ceilings.

THE INVENTION IN SUMMARY One purpose of the invention is to provide a method and device for climate control of rooms, whereby the problems and disadvantages cited

above can essentially be eliminated. This purpose is achieved in that the invention incorporates the special features cited in Patent Claims 1 and 3, respectively.

Further advantages and special features in the invention are evident in the following description, drawings, and dependent patent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with the aid of exemplary embodiments and with reference to attached drawings, on which FIG 1 is a principal sectional view that shows a room according to previously known technology, FIG 2 is a principal sectional view that shows a room with climate control according to an embodiment of the invention, FIG 3 is a partial enlargement of the portion marked with A in FIG 2 and FIG 4 is a partial enlargement of the portion in FIG 2 marked with B.

In a previously known embodiment according to FIG 1 a room 10 is constructed with walls 11 and ceiling 12. Room 10 is located between an existing flat ceiling structure 13 and an existing intermediate floor 14. Intake air from the surroundings is led in through a fresh air intake 15 to the interior of room 10. An air treatment assembly 16 is located between fresh air intake 15 and room 10. Air treatment assembly 16 suitably includes a pre-filter 17, a cooling and dehumidifying device 18, a first ventilator 19 and a final filter 20.

An inlet channel 27 connects fresh air intake 15 with room 10. Inlet channel 27 opens into room 10. Air from room 10 is directed out with the aid of a second ventilator 25 to the surroundings as discharge air through an outlet 26. An outlet tube 28 has an opening in room 10 and is connected with second ventilator 25. Humid and warm outside air is allowed freely to come

into the spaces surrounding room 10 through ventilation openings 33 in the outer walls 34 of the building.

Recessed in ceiling 12 are various kinds of ceiling fixtures 21 and similar. In walls 11 there are recessed electrical installations 22. Electrical installations 22 can also more or less extend into room 10. High humidity in the ambient air and a great difference of temperature between the side of the walls and ceiling facing inwards toward room 10 and the opposing outside of the watts and ceiling leads to condensation of water on the outside. Water can in this way be absorbed in the material that walls 11 and ceiling 12 are constructed of, which can lead to moisture and mold damage. It is also possible that water may penetrate into ceiling assemblies 21 and electrical installations 22 and thus shorten the service life of electrical components or cause short circuits.

THE INVENTION In FIG 2 a room is shown with climate control according to an embodiment of the invention. Room 10 is constructed in the same way as in the embodiment according to FIG 1 with walls 11 and ceiling 12, but is additionally provided with an encasing in the form of enclosed walls 23 and enclosed ceiling 24. Between walls, 11 ceiling 12, and corresponding enclosed walls 23 and enclosed ceiling 24 there is a free space 29. Space 29 is particularly well sealed and surrounds room 10. Air can be conducted to room 10 in the same way as in the embodiment according to FIG 1 via inlet channel 27 and air treatment assembly 16. Space 29 can also be limited to surround electrical installations and similar.

Outlet tube 28 in this embodiment lacks an outlet to the surroundings.

Instead, outlet tube 28 opens at one end into space 29. The discharge air transported away from room 10 by second ventilator 25 is thus led into space 29. The discharge air that enters and is transported through space 29 by second ventilator 25 has essentially the same temperature as the air in room

10. In this manner the condensation problems in the walls and ceiling disappear in room 10, since no differences in temperature are present.

Additionally, losses of energy are essentially diminished, since space 29 functions as an insulation barrier for room 10. In order to reduce energy losses further, a heat exchanger 32 can be positioned so that the tempered and treated discharge air can be used for cooling inlet air from fresh air intake 15.

FIG 3 shows an example of how ceiling fixture 21 can be positioned together with enclosed ceiling 24 and ceiling 12. Strut 30 in this embodiment is positioned in enclosed ceiling 24 but can also be positioned in flat ceiling 13. Ceiiing fixture 21 hangs on strut 30 and is provided with projecting flanges 31, on which the ceiling 12 of room 10 rests. In this embodiment there are no problems with seals around ceiling fixture 21 and no risk of deposit and collection of moisture, since both ceiling fixture 21 and ceiling 12 are surrounded on both sides by completely identical conditions of temperature and humidity.

FIG 4 shows in a similar way how various kinds of electrical installations 22, for example for electrical outlets, measuring devices, switch boxes, cabinets for the examination of films, and similar, can be arranged in space 29 between the walls 11 of the room and enclosed walls 23.