Method for restricting heat transmission through a wall opening and air curtain

Abstract

The invention relates to a method and air curtain for restricting heat transmission through a wall opening ( 120 ). Using the method according to the invention, an air curtain restricting heat transmission will be formed in front of the door opening. In the method on the first edge of the opening a blowing air flow going through a blow nozzle ( 12 ) is formed using a blower ( 20 ), and on the other edge of the opening a sucking air flow going through the suction opening ( 16 ) is formed. Advantageously the blowing air flow is formed at the lower edge of the opening and the sucking air flow at the upper edge of the opening. In this way, an air jet ( 40 ) will form in front of the door opening going from the blowing nozzle to the suction opening, and induced flows ( 42, 44 ) of air will form on both sides of the air jet, together forming an air curtain. The flowing of air through the door opening between the air jet and the vertical edges of the opening is reduced by side wallings ( 32 ). In the invention the induced air flow formed adjacent to the air jet is reversed back to the direction it came from in order to form a back flow ( 46 ) using an air deflector ( 30 ) placed on the other edge of the opening. The induced air flow and back flow form a circulating air flow alongside the air jet, with the temperature of the air mass being higher than the outside temperature. Because of the reduced temperature difference, the amount of heat moving through the opening is also reduced. Operation of the air curtain is controlled by an automatic control device ( 26 ).

1 . A method for restricting heat transmission through a wall opening, such as a door opening, in which method on the first edge of the opening a blowing air flow going through a blow nozzle is formed and on the second edge on the opening a sucking air flow going through a suction opening is formed, thereby forming an air curtain between the first and second edge of the opening, said air curtain comprising an air jet moving from the blow nozzle to the suction opening and induced air flows formed on both sides of the air jet, wherein the induced air flow formed alongside the air jet is reversed back to the direction it came from to form a back flow having a flow direction opposite to the flow direction on the air jet. 
   
   
       2 . A method according to  claim 1 , wherein the induced air flow is reversed into back flow by arranging an air deflector on the second edge of the opening for deflecting the direction of induced air flow. 
   
   
       3 . A method according to  claim 1 , wherein the blowing air flow is formed at the lower edge of the opening and sucking air flow at the upper edge of the opening. 
   
   
       4 . A method according to  claim 1 , wherein flowing of air between the air jet and vertical edges of the opening is restricted with side wallings. 
   
   
       5 . An air curtain to be formed in front of a building's wall opening, such as a door opening, comprising an intake channel, having a blow nozzle for blowing air, to be arranged on the first edge of the opening, an exhaust channel, having a suction opening for sucking air in, to be arranged on the second edge, opposing to the first edge of the opening, a connecting channel connecting the intake channel and exhaust channel, and a blower to be located in the connecting channel for forming an air jet between the blow nozzle and suction opening and an air deflector to be arranged on the second edge of the opening for reversing the induced air flow formed alongside the air jet back to the direction from which it came. 
   
   
       6 . An air curtain according to  claim 5 , wherein the intake channel is arranged to the lower edge of the opening and the exhaust channel and air deflector are arranged to the upper edge of the opening. 
   
   
       7 . An air curtain according to  claim 5 , wherein the length of the blow nozzle of the intake channel and the length of the suction opening of the exhaust channel are substantially equal to the complete width of the opening. 
   
   
       8 . An air curtain according to  claim 5 , wherein the position of the blow nozzle of the intake channel is adjustable for directing the air jet to the desired direction. 
   
   
       9 . An air curtain according to  claim 5 , wherein it further comprises side wallings along the vertical side edges of the opening. 
   
   
       10 . An air curtain according to  claim 5 , wherein it further comprises a control device for adjusting the position of the blow nozzle, for controlling the functioning of the blower and for controlling the blowing power of the blower.