Dark-out box for agricultural ventilation
View Patent ↗A dark-out apparatus is provided for use with a ventilation fan disposed on the wall of an agricultural building for passing ventilation air from one side to the other. The dark-out apparatus includes light-trapping media and first and second door members for holding the light-trapping media and being movable between open and closed positions and being openable away from the wall. When in the closed positions, the first and second door members cover a ventilation port of the fan, and when in the open positions, the first and second door members expose the ventilation port. When in the closed positions, distal sides of the first and second door members define an air gap. The air gap allows ventilation air to pass through, but does not allow ambient exterior light to pass through.
1 . A dark-out apparatus for use with a ventilation fan disposed on the wall of an agricultural building, the wall having an interior side and an exterior side, with a ventilation port passing through the wall from the exterior side to the interior side, the ventilation fan being mounted on the exterior side of the wall for passing ventilation air from one side to the other, the dark-out apparatus comprising:
a first light-trapping media;
a first door member for holding the first light-trapping media, the first door member being movable relative to the wall between an open position and a closed position and being openable away from the wall, the first door member comprising:
a first top panel;
a first bottom panel;
a first proximal side panel extending between the first top panel and the first bottom panel; and
a first distal side panel extending between the first top panel and the first bottom panel;
a second light-trapping media; and
a second door member for holding the second light-trapping media, the second door member being movable relative to the wall between an open position and a closed position and being openable away from the wall, the second door member comprising:
a second top panel;
a second bottom panel;
a second proximal side panel extending between the second top panel and the second bottom panel; and
a second distal side panel extending between the second top panel and the second bottom panel, wherein:
the first light-trapping media contacts the first distal side panel;
the second light-trapping media contacts the second distal side panel;
when in the closed positions, the first door member and the second door member cover the ventilation port, and when in the open positions, the first door member and the second door member expose the ventilation port;
when in the closed positions, the first distal side panel of the first door member and the second distal side panel of the second door member define an air gap, the air gap defined such that no imaginary straight line can pass from the exterior side to the interior side without intersecting at least one of the first door member and the second door member; and
the air gap allows ventilation air to pass through, but does not allow ambient exterior light to pass through.
2 . The apparatus according to claim 1 , wherein the first distal side panel and the second distal side panel overlap one another with respect to a direction from the exterior side to the interior side and have complementary shapes to define the air gap.
3 . The apparatus according to claim 2 , wherein the complementary shapes each includes two planar sections disposed at an angle greater than 0° such that the air gap is defined to have a bend with the angle greater than 0°.
4 . The apparatus according to claim 2 , wherein the complementary shapes each includes a curved section such that the air gap is defined to have a correspondingly curved section.
5 . The apparatus according to claim 2 , wherein the complementary shapes each includes plural planar sections disposed at angles greater than 0° such that the air gap is defined to have one or more corresponding bends.
6 . The apparatus according to claim 2 , wherein the first light-trapping media and the second light-trapping media are formed of fins of a non-linear shape, and the complementary shapes of the first distal side panel and the second distal side panel are similar to the non-linear shape of the fins.
7 . The apparatus according to claim 1 , wherein surfaces of the first distal side panel and the second distal side panel have light-absorbing characteristics.
8 . The apparatus according to claim 1 , wherein first door member has a width from the first proximal side panel to the first distal side panel that is longer than that of the second door member.
9 . The apparatus according to claim 1 , wherein each of the first door member and the second door member includes a central opening for receiving the first or second light-trapping media.
10 . The apparatus according to claim 9 , wherein the first door member and the second door member each includes a ridge or flange no more than one-half inch from an outer edge toward the central opening.
11 . A dark-out apparatus for use with a ventilation fan disposed on the wall of an agricultural building, the wall having an interior side and an exterior side, with a ventilation port passing through the wall from the exterior side to the interior side, the ventilation fan being mounted on the exterior side of the wall for passing ventilation air from one side to the other, the dark-out apparatus comprising:
a first door comprising four panels defining a central space;
a first light-trapping media having a light-trapping function, the first light-trapping media being movable relative to the wall between an open position and a closed position and being openable away from the wall, the first light-trapping member medium having interior and exterior faces, the first light-trapping media configured to be received in the central space of the first door and contact each of the panels of the first door; and
a second door comprising four panels defining a central space;
a second light-trapping media having a light-trapping function, the second light-trapping media being movable relative to the wall between an open position and a closed position and being openable away from the wall, the second light-trapping media having interior and exterior faces, the second light-trapping media configured to be received in the central space of the second door and contact each of the panels of the second door, wherein:
when in the closed positions, the first light-trapping media and the second light-trapping media cover the ventilation port, and when in the open positions, the first light-trapping media and the second light-trapping media expose the ventilation port;
when in the closed positions, a distal side panel of the first door and a distal side panel of the second door define an air gap therebetween; and
the air gap allows ventilation air to pass therethrough while having a light trapping effect.
12 . The apparatus according to claim 11 , wherein the air gap is defined such that no imaginary straight line can pass from the exterior side to the interior side without intersecting at least one of the first light-trapping media and the second light-trapping media.
13 . The apparatus according to claim 11 , wherein the distal side panel of the first door and the distal side panel of the second door overlap one another with respect to a direction from the exterior side to the interior side and have complementary shapes to define the air gap.
14 . The apparatus according to claim 13 , wherein the complementary shapes each includes two planar sections disposed at an angle greater than 0° such that the air gap is defined to have a bend with the angle greater than 0°.
15 . The apparatus according to claim 13 , wherein the complementary shapes each includes a curved section such that the air gap is defined to have a correspondingly curved section.
16 . The apparatus according to claim 13 , wherein the complementary shapes each includes plural planar sections disposed at angles greater than 0° such that the air gap is defined to have one or more corresponding bends.
17 . The apparatus according to claim 11 , wherein surfaces of the distal side panel of the first door and the distal side panel of the second door have light-absorbing characteristics.
18 . The apparatus according to claim 11 , wherein the first door has a width from a proximal side to the distal side panel of the first door that is longer than that of the second door.
19 . The apparatus according to claim 11 , wherein a peripheral section of the first door and the second door extends no more than one-half inch from an outer edge toward the central opening of the respective first door and the second door.