Browse Forums Heating, Cooling & Insulation 1 Sep 04, 2010 5:20 pm We've recently had handover and our new ducted heating/cooling will be commissioned before too long. Today I peered through the return air vent (which is vented up through a wall cavity). I was quite surprised to see a bare wall cavity, our wall insulation etc. Should it not have a sealed return air box with the duct connected to it? I haven't yet had a chance to see if the actual wall cavity is all sealed off from the roof yet, or whether the duct is just hanging into that space Is there any Australian standard or regulation that might cover this? What's behind your return air vent? Re: have you looked behind your return air vent/grille? 2Sep 04, 2010 6:20 pm Trinity We've recently had handover and our new ducted heating/cooling will be commissioned before too long. Today I peered through the return air vent (which is vented up through a wall cavity). I was quite surprised to see a bare wall cavity, our wall insulation etc. Should it not have a sealed return air box with the duct connected to it? I haven't yet had a chance to see if the actual wall cavity is all sealed off from the roof yet, or whether the duct is just hanging into that space Is there any Australian standard or regulation that might cover this? What's behind your return air vent? Sound pretty normal to me. If you were to actually get inside and look up you will see the return box and the start of the duct run. This part will be sealed so no drama about heat leaking into the roof cavity. Re: have you looked behind your return air vent/grille? 3Sep 05, 2010 12:06 am The problem with using a building cavity as a plenum is the possibility that it is not well sealed thus turning a closed system into an open one. Unconditioned air may be entrained into the HVAC system making it less efficient I would also be concerned about air quality with insulation fibres exposed to the circuit. Re: have you looked behind your return air vent/grille? 4Sep 05, 2010 8:21 pm thanks dymonite69 and ajw. I managed to look inside and take pics today. The duct is just hanging into the wall cavity, but it does appear they have sealed the cavity at the top. We'll take a closer look at how well it's sealed once we get into the roof cavity after the heating/cooling has been commissioned. On closer inspection there is no wall insulation here. Pic is camera pointed up the wall cavity to the ceiling... http://i562.photobucket.com/albums/ss69/sierra_099/IMG_1139.jpg http://i562.photobucket.com/albums/ss69/sierra_099/IMG_1142.jpg Re: have you looked behind your return air vent/grille? 5Sep 05, 2010 9:12 pm Is the duct sealed around the outside as it penetrates the cavity? How do you remove one of these ceiling air con vents? And is it possible to disconnect the duct joined to the vent from inside the house, without going into the roof cavity? 0 5834 Thanks mate. Yeah good points! Leaning towards Option 3 to get a bit extra space in the cabinets but not going too crazy high (and expensive). Would require a mini… 13 39276 Old Home Restoration / Renovation Hi, just discovered all these junks left behind under the floor. Could any of these be asbestos? Best to leave as it is or clean up? Thank you for your thoughts 0 8049 |