Method and apparatus for operating ducted fumehoods with increased energy efficiency

Abstract

A method for operating a ducted fumehood with increased energy efficiency, wherein the method comprises: passing exhaust air from the ducted fumehood through a heat exchanger, and passing other air through the heat exchanger, so as transfer heat content from the exhaust air to the other air, or to transfer heat content from the other air to the exhaust air, so as to temperature-condition the other air.

What is claimed is: 
     
         1 . A method for operating a ducted fumehood with increased energy efficiency, wherein the method comprises:
 passing exhaust air from the ducted fumehood through a heat exchanger, and passing other air through the heat exchanger, so as transfer heat content from the exhaust air to the other air, or to transfer heat content from the other air to the exhaust air, so as to temperature-condition the other air.   
     
     
         2 . A method according to  claim 1  wherein the exhaust air from the ducted fumehood is passed through a filter before it is introduced into the heat exchanger as a filtered air line. 
     
     
         3 . A method according to  claim 2  wherein the other air comprises fresh air introduced into a building containing the ducted fumehood as a fresh air line. 
     
     
         4 . A method according to  claim 3  wherein the filtered air line and the fresh air line pass through the heat exchanger but do not communicate with one another. 
     
     
         5 . A method according to  claim 4  wherein the heat exchanger is configured to permit the transfer of heat energy from the filtered air line to the fresh air line and vice versa. 
     
     
         6 . A method according to  claim 3  wherein the heat exchanger comprises a first heat exchanger element interposed in the airflow of the filtered air line, and a second heat exchanger element interposed in the airflow of the fresh air line, and further wherein a fluid line connects the first heat exchanger element with the second heat exchanger element. 
     
     
         7 . A method according to  claim 6  wherein the heat exchanger comprises a heat pump, and further wherein the fluid line comprises a refrigerant line filled with a refrigerant, and further comprising a compressor for selectively compressing the refrigerant. 
     
     
         8 . A method according to  claim 7  further comprising a reversing valve disposed in the refrigerant line, such that the heat exchanger comprises a reversible heat pump. 
     
     
         9 . A method according to  claim 8  wherein the reversible heat pump extracts heat content from the filtered air line and adds that heat content to the fresh air line by directing liquid refrigerant from the first heat exchanger element toward the second heat exchanger element. 
     
     
         10 . A method according to  claim 8  wherein the reversible heat pump extracts heat content from the fresh air line and adds that heat content to the filtered air line by directing liquid refrigerant from the second heat exchanger element toward the first heat exchanger element. 
     
     
         11 . Apparatus for operating a ducted fumehood with increased energy efficiency, wherein the apparatus comprises:
 a heat exchanger configured to receive exhaust. air from the ducted fumehood, and to receive other air, so as to transfer heat content from the exhaust air to the other air, or to transfer heat content from the other air to the exhaust air, so as to temperature-condition the other air.   
     
     
         12 . Apparatus according to  claim 11  wherein the exhaust air from the ducted fumehood is passed through a filter before it is introduced into the heat exchanger as a filtered air line. 
     
     
         13 . Apparatus according to  claim 12  wherein the other air comprises fresh air introduced into a building containing the ducted fumehood as a fresh air line. 
     
     
         14 . Apparatus according to  claim 13  wherein the filtered air line and the fresh air line pass through the heat exchanger but do not communicate with one another. 
     
     
         15 . Apparatus according to  claim 14  wherein the heat exchanger is configured to permit the transfer of heat energy from the filtered air line to the fresh air line and vice versa. 
     
     
         16 . Apparatus according to  claim 13  wherein the heat exchanger comprises a first heat exchanger element interposed in the airflow of the filtered air line, and a second heat exchanger element interposed in the airflow of the fresh air line, and further wherein a fluid line connects the first heat exchanger element with the second heat exchanger element. 
     
     
         17 . Apparatus according to  claim 16  wherein the heat exchanger comprises a heat pump, and further wherein the fluid line comprises a refrigerant line filled with a refrigerant, and further comprising a compressor for selectively compressing the refrigerant. 
     
     
         18 . Apparatus according to  claim 17  further comprising a reversing valve disposed in the refrigerant line, such that the heat exchanger comprises a reversible heat pump. 
     
     
         19 . Apparatus according to  claim 18  wherein the reversible heat pump extracts heat content from the filtered air line and adds that heat content to the fresh air line by directing liquid refrigerant from the first heat exchanger element toward the second heat exchanger element. 
     
     
         20 . Apparatus according to  claim 18  wherein the reversible heat pump extracts heat content from the fresh air line and adds that heat content to the filtered air line by directing liquid refrigerant from the second heat exchanger element, toward the first heat exchanger element. 
     
     
         21 . A system comprising:
 a ducted fumehood;   a heat exchanger configured to receive exhaust air from the ducted fumehood, and to receive other air, so as to transfer heat content from the exhaust air to the other air, or to transfer heat content from the other air to the exhaust air, so as to temperature-condition the other air.