Summer bypass for heat recovery unit

Abstract

There is provided a heat recovery ventilation unit comprising a first air flow path and a second air flow path and a heat exchanger in which the first air flow path is in heat exchange contact with the second air flow path; the unit further comprising an air flow path selector in the first air flow path which is arranged to select between the first air flow path and a third air flow path which bypasses the heat exchanger; wherein the air flow path selector is located between an inlet filter of the first air flow path and the heat exchanger. Providing the bypass selector between the filter and the heat exchanger, air is always filtered, even in the bypass mode, thus reducing particulate matter drawn into the building during bypass operation.

1 . A heat recovery ventilation unit comprising a first air flow path and a second air flow path and a heat exchanger in which the first air flow path is in heat exchange contact with the second air flow path;
 the unit further comprising an air flow path selector in the first air flow path which is arranged to select between the first air flow path and a third air flow path which bypasses the heat exchanger;   wherein the air flow path selector is located between an inlet filter of the first air flow path and the heat exchanger.   
     
     
         2 . A heat recovery unit as claimed in  claim 1 , wherein the heat recovery unit comprises structures formed from plastic which form the third air flow path. 
     
     
         3 . A heat recovery unit as claimed in  claim 1 , wherein the air flow path selector comprises a barrier which is movable between a first configuration in which air is directed to the heat exchanger and a second configuration in which air is directed to bypass the heat exchanger. 
     
     
         4 . A heat recovery unit as claimed in  claim 3 , wherein the barrier is operable to slide between the first configuration and the second configuration. 
     
     
         5 . A heat recovery unit as claimed in  claim 4 , wherein the barrier is a foldable barrier and wherein one of the first and second configurations is the folded state of the foldable barrier and the other of the first and second configurations is the unfolded state of the foldable barrier. 
     
     
         6 . A heat recovery unit as claimed in  claim 5 , wherein the first configuration is the folded configuration and the second configuration is the unfolded configuration. 
     
     
         7 . A heat recovery unit as claimed in  claim 5 , wherein the foldable barrier comprises a first section, a second section and a third section, the first section being foldably connected to the second section and the second section being foldably connected to the third section, and wherein in the folded configuration the fold between the first section and the second section is substantially a right angle and the fold between the second section and the third section is substantially 180 degrees so that the second and third sections are substantially parallel. 
     
     
         8 . A heat recovery unit as claimed in  claim 7 , wherein the barrier is driven between the first and second configurations by an electric motor. 
     
     
         9 . A heat recovery unit as claimed in  claim 1 , wherein the barrier comprises a plurality of sections, each slidable with respect to the others such that the sections are movable between an overlapped configuration and a non-overlapped configuration. 
     
     
         10 . A heat recovery unit as claimed in  claim 1 , wherein the heat recovery unit is configurable such that either the first flow path or the second flow path is for incoming air.