Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D5/00—Hot-air central heating systems; Exhaust gas central heating systems
  • F24D5/06—Hot-air central heating systems; Exhaust gas central heating systems operating without discharge of hot air into the space or area to be heated
  • F24D5/10—Hot-air central heating systems; Exhaust gas central heating systems operating without discharge of hot air into the space or area to be heated with hot air led through heat-exchange ducts in the walls, floor or ceiling

Definitions

• the present invention relates to a method for heating and/or cooling the air in a building, the building being of the type in which supply air is caused to flow in through the roof which is a so-called counterflow-type roof, i.e. the air flowing from outside and in through the insulating layer of the roof counter ⁇ acts the exchange of heat through the roof, and the floor consisting of a base slab preferably made of concrete.
• the object of the present invention is to maintain, in buildings with a counterflow roof and so-called dynamic insulation, cooling of the incoming air when the air temperature is high, and heating of said air when the air temperature is low, especially at high air flow rates, in a simple and cost-saving manner in respect of installa ⁇ tion as well as operation.
• a further object of the invention is to provide both cooling and heating without ' necessitating two separate systems. According to the invention, these and other objects are achieved in that the base slab is heated and cooled, respectively, by means of conduits or ducts extending in or under said base slab, and that the base slab is used as a radiation source for heating and, respectively, as a radiation receiver for cooling said roof and the air supplied therethrough.
• the Figure shown in the drawing is a cross-sectional view of a building according to the invention. Detailed descriptio ⁇ ⁇ Of the invention
• a roof structure which is of counterflow-type and is generally designated 1 comprises the outer roofing 2, structural beams 3 and insulation 4.
• the beams 3 are suitably open, i.e. they have a web which allows air to pass, such that a coherent air gap 5 is defined above the insulation.
• the insulation may conveniently consist of mineral wool and rests on a pressure drop layer 6 which simul ⁇ taneously can form the ceiling.
• the pressure drop layer serves to uniformly distribute the air flow over the entire roof surface by the formation of a positive pressure in the gap 5, and may consist of an air-permeable cloth, a perforated board or the like.
• the ventilation air is blown under the roof by a fan 7 mounted on the roof, the air being uniformly distributed over the roof surface and supplied through the insulation and the pressure drop layer, as indicated by the arrows.
• the building rests on a base slab 8 which is disposed directly on the ground.
• Conduits 9 are positioned under the base slab, and a heating medium, such as water, is caused to circulate in said conduits.
• the conduits are preferably laid under the concrete but can also be cast into the base slab. It is, of course, perfectly feasible to heat the base slab by means of electric wires instead of conduits filled with a heating medium.
• the heat or, respectively, the cold comes on the one one hand from a heat pump 10 which can recover energy from the ventilation air leaving the building and, on the other hand, from a deep-bored well 11, superficial ground heat or the like.
• the inventive method is carried out as follows. Via the conduits 9, the base slab 8 is suitably cooled by accumulation at night when the price of energy is lower. To make the foundation soil assist in such accumulation, no insulation should be applied under the base slab.
• the roof surface can be cooled by radia ⁇ tion, whereby it cools the supply air and radiates less heat to the premises.
• the cool base slab cools the air in the building by convection, but the major part of the heat transfer occurs by cooling of the roof surface and the supply air by means of radiation between the roof and the slab.
• the great 5 need for cooling in existing buildings is largely due to the fact that the surrounding surfaces are heated and act as heat radiation sources which are difficult to cool by convection by means of air which for this purpose needs to be exceedingly cool or be available in large amounts.
• the cool base slab will act as a radiation receiver which absorbs heat radiation from the surrounding warmer surfaces, especially from the roof whose surface in its entirety faces the floor.
• the building described above can be heated corre ⁇ spondingly, by using the same equipment as described above for the cooling process.
• the difference is that the heating medium is heated before being allowed to pass the base slab, the heating advantageously being effected by night-time accumulation in the base slab and in the foundation soil.
• Floor heating is recognised as the best method for heating premises, since the air temperatures can be kept lower without the tempera- ture feeling disagreeable.
• Floor heating also permits low temperatures of the heating medium, which can be utilised to achieve an extremely low energy con ⁇ sumption by means of a heat pump. When the outdoor air passes through the insulation of the roof, it is preheated by the rising flow of heat.
• the ceiling surface 6 and the downwardly directed flow of air will also be preheated, before the air reaches the sojourn area close to the floor.
• the ceiling surface 6 and the downwardly directed flow of air will also be preheated, before the air reaches the sojourn area close to the floor.
• also extremely large amounts of air can be supplied to the premises, even if the outdoor temperature is low, without deteriorating the indoor heat comfort.
• the power output from the slab can be increased to a considerable extent or, vice versa, the temperature of the heating medium can be lowered with the power output retained, which increases the possibility of using low-temperature energy from solar heat and the like.
• This is due to the fact that in normal use of floor heating systems, the heat transfer between the concrete slab and the indoor air occurs almost exclusively by convection, since the difference in temperature between the floor surface and the surrounding roof and walls is insignificant.
• the concrete slab is supplemented with a counterflow roof according to the present invention, the difference in temperature between floor and roof will be considerable, because the supply air cools or, where appropriate, heats the ceiling. As a result, the radiation share of the heat transfer between floor and roof will increase drastically. In other words, roof and floor can be said to strive to reach the same temperature.
• the heat balance of a building can be expressed
• the first factor expresses the radiation between floor and roof, which has been negligible in previous applications.
• the second factor expresses the convection from floor to air and further from air to roof.
• the third factor expresses the heat requirement for heating in- coming outdoor air to indoor temperature.
• the invention also affords an opportunity to provide, in a simple and cost-saving manner, accumulation of energy from periods of low-price energy, for example at night, to periods in which energy is more expensive. This is possible since in most cases the requirement for air at night is small, whereby the supply of air through the counterflow roof may be reduced to a minimum. Consequently, the difference in temperature between the concrete slab and the roof surface is reduced to a corresponding degree, and thus also the radiation is reduced. These circumstances can be used for recharging by increasing the temperature of the concrete slab a few degrees at night, without energy being lost owing to an increased temperature in the premises. When the supply of air again increases in the day-time, the emission of heat from the slab will increase and, as a :result, the slab will be discharged.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Building Environments (AREA)

Applications Claiming Priority (2)

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• 1988
  • 1988-10-05 SE SE8803536A patent/SE8803536L/ not_active Application Discontinuation
• 1989
  • 1989-10-04 WO PCT/SE1989/000544 patent/WO1990004135A1/en not_active Application Discontinuation
  • 1989-10-04 EP EP19890910953 patent/EP0440678A1/de not_active Withdrawn
  • 1989-10-04 AU AU43205/89A patent/AU4320589A/en not_active Abandoned

Non-Patent Citations (1)

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