Photocatalytic filtration in vehicle hvac system

Abstract

A photocatalyst filtration system for a vehicle includes a housing having an airflow path, and a filter configured to filter air flowing in the airflow path, the filter having a first photocatalyst and a second photocatalyst. The system further includes a first ultraviolet (UV) light source disposed proximate the filter and configured to energize the first photocatalyst, and a second UV light source disposed proximate the filter and configured to produce light having a shorter wavelength than light produced by the first UV light source, and configured to energize the second photocatalyst. One of the first photocatalyst or the second photocatalyst is configured to remove odor from the air. The other of the first photocatalyst or the second photocatalyst is configured to remove bacteria from the air.

What is claimed is: 
     
         1 . A filtration system for a vehicle, comprising:
 a housing having an airflow path;   a filter disposed in the housing and configured to filter air flowing in the airflow path, the filter comprising a first photocatalyst and a second photocatalyst proximate an upstream surface of the filter;   a UV-A light source disposed proximate the upstream surface and configured to energize the first photocatalyst; and   a UV-C light source disposed proximate the upstream surface and configured to produce light having a shorter wavelength than light produced by the UV-A light source, and configured to energize the second photocatalyst, wherein:
 the UV-A light source emits UV-A light along a UV-A light field on the upstream surface of the filter, 
 the UV-C light source emits UV-C light along a UV-C light field on the upstream surface of the filter, and 
 the UV-A light field and the UV-C light field overlap and encompass an entirety of the upstream surface. 
   
     
     
         2 . The filtration system of  claim 1 , wherein the first photocatalyst and the second photocatalyst are the same and include between 0.1 and 0.5 g/m 2  of TiO 2 . 
     
     
         3 . The filtration system of  claim 1 , wherein:
 the UV-A light source comprises a plurality of UV-A lightbulbs;   the UV-C light source comprises a plurality of UV-C lightbulbs; and   the UV-A lightbulbs and the UV-C lightbulbs are disposed in a staggered arrangement along the airflow path.   
     
     
         4 . The filtration system of  claim 1 , wherein one of the first photocatalyst or the second photocatalyst is configured to remove odor from the air, and the other of the first photocatalyst or the second photocatalyst is configured to remove bacteria from the air. 
     
     
         5 . The filtration system of  claim 1 , wherein the filter further comprises a carbon layer configured to remove particulate from the air. 
     
     
         6 . The filtration system of  claim 1 , wherein the UV-A light source and the UV-C light source are disposed upstream from the filter. 
     
     
         7 . The filtration system of  claim 1 , wherein the UV-A light source is disposed a first offset distance away from the filter and the UV-C light source is disposed a second offset distance away from the filter different from the first offset distance. 
     
     
         8 . The filtration system of  claim 7 , wherein:
 the housing comprises:
 a forward wall opposing the filter; 
 an upper surface formed at an upper periphery of the forward wall; 
 a lower surface formed at a lower periphery of the forward wall; and 
 an air inlet formed at a side wall of the housing between the forward wall and the filter; and 
   one of the UV-A light source or the UV-C light source is coupled to the forward wall and the other of the UV-A light source or the UV-C light source is coupled to at least one of the upper surface or the lower surface.   
     
     
         9 . The filtration system of  claim 8 , wherein the UV-A light source comprises a first lightbulb coupled to the upper surface and a second lightbulb coupled to the lower surface. 
     
     
         10 . The filtration system of  claim 1 , wherein the vehicle is a ride sharing vehicle or an autonomous vehicle. 
     
     
         11 . A filtration system for a vehicle, comprising:
 a housing;   a filter having a filter upstream surface and a photocatalyst disposed proximate the filter upstream surface; and   a plurality of UV lightbulbs disposed in the housing upstream and offset from the filter and configured to provide both UV-A and UV-C light to an entirety of the filter upstream surface, wherein the photocatalyst is configured to be energized by both the UV-A light and the UV-C light.   
     
     
         12 . The filtration system of  claim 11 , wherein the photocatalyst includes between  0 . 1  and 0.5 g/m 2  of TiO 2 . 
     
     
         13 . The filtration system of  claim 11 , wherein the plurality of UV lightbulbs comprises a plurality of UV-A lightbulbs and a plurality of UV-C lightbulbs, and wherein the UV-A lightbulbs and the UV-C lightbulbs are disposed in a staggered arrangement along an airflow path through the housing. 
     
     
         14 . The filtration system of  claim 11 , wherein the filter further comprises a carbon layer configured to remove particulate from air flowing through the filter. 
     
     
         15 . The filtration system of  claim 11 , wherein:
 the housing comprises:
 a forward wall opposing the filter; 
 an upper surface formed at an upper periphery of the forward wall; 
 a lower surface formed at a lower periphery of the forward wall; and 
 an air inlet formed at a side wall of the housing between the forward wall and the filter; and 
   a first lightbulb of the plurality of UV lightbulbs is coupled to the forward wall and a second lightbulb of the plurality of UV lightbulbs is coupled to at least one of the upper surface or the lower surface.   
     
     
         16 . A filtration system for a vehicle, comprising:
 a housing having an airflow path;   a filter disposed in the housing and configured to filter air flowing through the housing, the filter comprising a first photocatalyst and a second photocatalyst proximate an upstream surface of the filter;   a plurality of UV lightbulbs disposed in the housing upstream and offset from the filter and configured to provide both UV-A light and UV-C light to an entire surface of the filter, wherein:
 the UV-A light is configured to energize the first photocatalyst and the UV-C light is configured to energize the second photocatalyst, and 
 the plurality of UV lightbulbs are disposed in a staggered arrangement along the airflow path. 
   
     
     
         17 . The filtration system of  claim 16 , wherein the first photocatalyst and the second photocatalyst are the same and include between 0.1 and 0.5 g/m 2  of TiO 2 . 
     
     
         18 . The filtration system of  claim 16 , wherein the plurality of UV lightbulbs comprises:
 a plurality of UV-A lightbulbs configured to emit the UV-A light along a UV-A light field; and   a plurality of UV-C lightbulbs configured to emit UV-C light along a UV-C light field, wherein the UV-A light field and the UV-C light field overlap.   
     
     
         19 . The filtration system of  claim 16 , wherein the filter further comprises a carbon layer configured to remove particulate from the air. 
     
     
         20 . The filtration system of  claim 16 , wherein:
 the housing comprises:
 a forward wall opposing the filter; 
 an upper surface formed at an upper periphery of the forward wall; 
 a lower surface formed at a lower periphery of the forward wall; and 
 an air inlet formed at a side wall of the housing between the forward wall and the filter; and 
   a first lightbulb of the plurality of UV lightbulbs is coupled to the forward wall and a second lightbulb of the plurality of UV lightbulbs is coupled to at least one of the upper surface or the lower surface.