Venting system for minimizing condensation in a lighting assembly
View Patent ↗In one aspect, the invention is a lighting assembly comprising a housing defining an internal space within the housing, and an ambient space surrounding the housing, a light source within the internal space; a high capacity desiccant within the internal space, the high capacity desiccant being nonregenerating at temperatures of up to about 50 degrees Celsius and about 11.0% relative humidity; and a diffusion tube having a first opening proximate to the internal space and a second opening proximate to the ambient space, the diffusion tube providing gaseous communication between the internal space and the ambient space.
1. A lighting assembly comprising:
a) a housing defining an internal space within said housing, and an ambient space surrounding said housing;
b) a light source within the internal space;
c) high capacity desiccant within the internal space, said high capacity desiccant being nonregenerating at temperatures of up to about 50 degrees Celsius and about 11% relative humidity; and
d) a diffusion tube having a first opening proximate to the internal space and a second opening proximate to the ambient space, said diffusion tube providing gaseous communication between the internal space and the ambient space.
2. The lighting assembly of claim 1 , in which said high capacity desiccant will absorb at least about 4 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
3. The lighting assembly of claim 1 , in which said high capacity desiccant will absorb at least about 7 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
4. The lighting assembly of claim 1 , in which said high capacity desiccant comprises MgO and at least 5% MgCl2.
5. The lighting assembly of claim 1 , in Which said high capacity desiccant comprises 5% to 80% by weight MgCl2 and at least 5% MgO.
6. The lighting assembly of claim 1 , in which said high capacity desiccant comprises 35% to 70% by weight MgCl2 and at least 5% MgO.
7. The lighting assembly of claim 1 , in which said high capacity desiccant comprises approximately equal parts MgCl2 and MgO.
8. The lighting assembly of claim 1 , further comprising a microporous membrane covering at least one opening of said diffusion tube.
9. The lighting assembly of claim 8 , in which said microporous membrane is ePTFE.
10. The lighting assembly of claim 9 , in which said ePTFE membrane is oleophobic.
11. The lighting assembly of claim 1 in which the diffusion tube comprises; an adhesive layer having at least one opening therein, said opening located over a vent hole in said lighting assembly, the layer of adhesive having a channel cut within it to provide a pathway for air, the layer attached to the housing and covered with a polymeric film having an opening therein to form an diffusion tube exit.
12. A lighting assembly comprising:
a) a housing containing a light source, said housing defining an internal space within said housing, and an ambient space surrounding said housing;
b) first desiccant within the internal space, said first desiccant being of high capacity and being nonregenerating at temperatures of up to about 50 degrees Celsius and about 11% relative humidity;
c) a container within the internal space, said container having an air impermeable and water vapor permeable surface and containing second desiccant;
d) a heat source adjacent to the air impermeable and water vapor surface such that the second desiccant is heated to a temperature whereby moisture is driven from the second desiccant; and
e) a diffusion tube having a first open end proximate to the second desiccant and a second open end proximate to the ambient space, said diffusion tube providing gaseous communication between the second desiccant and the ambient space.
13. The lighting assembly of claim 12 , in which the light source and said heat source are the same.
14. The lighting assembly of claim 12 , in which said high capacity desiccant will absorb at least about 4 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
15. The lighting assembly of claim 12 , in which said high capacity desiccant will absorb at least about 7 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
16. The lighting assembly of claim 12 in which said high capacity desiccant comprises MgO and at least 5% MgCl2.
17. The lighting assembly of claim 12 , in which said high capacity desiccant comprises 5% to 80% by weight MgCl2 and at least 5% MgO.
18. The lighting assembly of claim 12 , in which said high capacity desiccant comprises 35% to 70% by weight MgCl2 and at least 5% MgO.
19. The lighting assembly of claim 12 , in which said high capacity desiccant comprises approximately equal parts MgCl2 and MgO.
20. The lighting assembly of claim 12 , further comprising a microporous membrane covering at least one opening of said diffusion tube.
21. The lighting assembly of claim 20 , in which said microporous membrane is ePTFE.
22. The lighting assembly of claim 21 , in which said ePTFE membrane is oleophobic.
23. The lighting assembly of claim 12 in which the diffusion tube comprises; an adhesive layer having at least one opening therein, said opening located over a vent hole in said lighting assembly, the layer of adhesive having a channel cut within it to provide a pathway for air, the layer attached to the housing and covered with a polymeric film having an opening therein to form an diffusion tube exit.
24. A method of reducing condensation in a lamp enclosure, the method comprising:
a) providing high capacity desiccant within said lamp enclosure, said high capacity desiccant being nonregenerating at temperatures of up to about 50 degrees Celsius and about 11% relative humidity; and
b) providing a diffusion tube, said diffusion tube providing gaseous communication between the interior of the lamp enclosure and the surrounding atmosphere.
25. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant will absorb at least about 4 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
26. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant will absorb at least about 7 grams of water per 10 grams of high capacity desiccant when exposed to an environment of about 22 degrees Celsius and about 50 percent relative humidity for 7 days.
27. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant comprises MgO and at least 5% MgCl2.
28. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant comprises 5% to 80% by weight MgCl2 and at least 5% MgO.
29. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant comprises 35% to 70% by weight MgCl2 and at least 5% MgO.
30. The method of reducing condensation in a lamp enclosure of claim 24 , in which said high capacity desiccant comprises approximately equal parts MgCl2 and MgO.
31. The method of reducing condensation in a lamp enclosure of claim 24 , further comprising a microporous membrane covering at least one opening of said diffusion tube.
32. The method of reducing condensation in a lamp enclosure of claim 31 , in which said microporous membrane is ePTFE.
33. The method of reducing condensation in a lamp enclosure of claim 32 , in which said ePTFE membrane is oleophobic.
34. The lighting assembly of claim 26 in which the diffusion tube comprises; an adhesive layer having at least one opening therein, said opening located over a vent hole in said lighting assembly, the layer of adhesive having a channel cut within it to provide a pathway for air, the layer attached to the housing and covered with a polymeric film having an opening therein to form an diffusion tube exit.
35. A vehicle lighting assembly comprising:
a) a housing containing a light source, said housing defining an internal space within said housing and an ambient space surrounding said housing;
b) desiccant disposed within the internal space, said desiccant comprising at least about 20% by weight MgCl2 and at least 5% MgO;
c) a diffusion tube having a first open end proximate to the internal space, and a second open end proximate to the ambient space, said diffusion tube providing gaseous communication between the internal space and the ambient space.
36. The automotive lighting assembly of claim 35 , further comprising a microporous membrane covering at least one opening of said diffusion tube.
37. The automotive lighting assembly of claim 36 , in which said microporous membrane is ePTFE.
38. The automotive lighting assembly of claim 37 , in which said ePTFE membrane is oleophobic.
39. The lighting assembly of claim 35 in which the diffusion tube comprises; an adhesive layer having at least one opening therein, said opening located over a vent hole in said lighting assembly, the layer of adhesive having a channel cut within it to provide a pathway for air, the layer attached to the housing and covered with a polymeric film having an opening therein to form an diffusion tube exit.
40. An automotive lighting assembly comprising:
a) a housing containing a light source, said housing defining an internal space within said housing and an ambient space surrounding said housing;
b) first desiccant disposed within the internal space, said first desiccant comprising at least about 20% MgCl2 by weight and at least 5% MgO;
c) a container within the internal space, said container having an air impermeable and water vapor permeable surface and containing second desiccant;
d) a heat source adjacent to the air impermeable and water vapor permeable surface of said container such that the second desiccant is heated to a temperature whereby moisture is driven from the second desiccant; and
e) a diffusion tube having a first open end proximate to the second desiccant and a second open end proximate to the ambient space, said diffusion tube providing gaseous communication between the second desiccant and the ambient space.
41. The lighting assembly of claim 40 , in which the light source and said heat source are the same.
42. The lighting assembly of claim 40 , further comprising a microporous membrane covering at least one opening of said diffusion tube.
43. The lighting assembly of claim 42 , in which said microporous membrane is ePTFE.
44. The lighting assembly of claim 43 , in which said ePTFE membrane is oleophobic.
45. The lighting assembly of claim 40 in which the diffusion tube comprises; an adhesive layer having at least one opening therein, said opening located over a vent hole in said lighting assembly, the layer of adhesive having a channel cut within it to provide a pathway for air, the layer attached to the housing and covered with a polymeric film having an opening therein to form an diffusion tube exit.