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Normally I would ask 1)What size is the room? 2)What size is the supply duct feeding the future home theater room from the supply plenum? The second return located in the wall cavity (assuming it was 2x4 construction, 16" o.c.) is now sealed leaving an opening from the return plenum direct into the room through the wall. Is this correct? 3)What size is this opening? 4) Are your heat generating pieces of equipment to be located inside the room or a dedicated equipment closet? This can determine if your supply may be undersized for your future loads. The original builders may not have anticipated increased number of people and equipment in the space.
Typically a well designed ventialtion system with manual dampers will have a low return for use during the cool season and a high return for use during the hot season. During the cold season you would close the upper return grille and open the upper grille allowing the lower return to draw warm air down to the floor before getting back to the return plenum. During the hot season, the lower grille would be closed and the upper grille opened to remove hot air at the top and to draw the cold air (that would normally fall to the floor) to be drawn up to the ceiling.
If you seal one grille, it may be enough for a return but your comfort level may suffer. Leaving the upper grille open will likely be the best comfort compromise but you then allow a more direct path for sound to travel. If you were willing to acoustically line the return plenum, that would help matters greatly. You can also line the supply duct or install a commercial silencer.
Hope this helps.
Bruce
| Originally Posted by bogg It appears that my house started with supplies only in the basment. In one room (unfortunately my HT room), the main supply and return trunk(?) is located. It looks like a hole was made in one of the main supply ducts to add a supply to this room, and two holes were made in the return very close to one another to make returns. One is high, and the other made high but connected the a lower opening in the wall via a stud cavity. The latter is rather large and it is basically getting dust and other nice things spread up into the cavites between the basement and first floor. If I patch it up, leaving just the one high return (8x6), should that be sufficient? BTW, to be clearer, this room has two supplies. The other room in the basement also has two supplies. Thanks. |
Normally I would ask 1)What size is the room? 2)What size is the supply duct feeding the future home theater room from the supply plenum? The second return located in the wall cavity (assuming it was 2x4 construction, 16" o.c.) is now sealed leaving an opening from the return plenum direct into the room through the wall. Is this correct? 3)What size is this opening? 4) Are your heat generating pieces of equipment to be located inside the room or a dedicated equipment closet? This can determine if your supply may be undersized for your future loads. The original builders may not have anticipated increased number of people and equipment in the space.
Typically a well designed ventialtion system with manual dampers will have a low return for use during the cool season and a high return for use during the hot season. During the cold season you would close the upper return grille and open the upper grille allowing the lower return to draw warm air down to the floor before getting back to the return plenum. During the hot season, the lower grille would be closed and the upper grille opened to remove hot air at the top and to draw the cold air (that would normally fall to the floor) to be drawn up to the ceiling.
If you seal one grille, it may be enough for a return but your comfort level may suffer. Leaving the upper grille open will likely be the best comfort compromise but you then allow a more direct path for sound to travel. If you were willing to acoustically line the return plenum, that would help matters greatly. You can also line the supply duct or install a commercial silencer.
Hope this helps.
Bruce
