I am curious about the configuration of the vents in this new build manufactured home. Other than the whole house return air vent and the supply ducts in the floors, I can’t quite understand the other ceiling vents in the home.
They look like vents to act as return air back into the system from each room. You’ll often find them in larger rooms (master bed/bath for example) that are closed off by a door from the main return air. I’m not sure why there would be one so close to the main return air duct. Perhaps there was once a door or wall between the main opening and smaller one? Or, could just be a mistake at the time of construction. The function is all about balancing air in the HVAC system.
The small duct in the return plenum is likely outdoor air.
The square ducts are jumper ducts. If you don’t let the air out of a closed door room, your supply airflow will slow, or stop.
It does not matter how close it is. You can see that there is a door jamb in the lower right. It’s for that room.
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Yes! A jumper duct. It makes sense now. If I am understanding this correctly, the jumper ducts are not connected to the furnace but are simply a network of static ducts between all the rooms to transfer air to the vent near the main return vent which would be beneficial in the event that a door was closed. Is that right? So the vent near the main return is likely acting as a supply for the return and the others are returns. Yeah, that’s difficult to explain.
got it… seems odd they wouldn’t have just tied it into the main duct above rather than cutting another hole and all that.
I haven’t seen one installed in a Manufactured Home (yet), but I could see the benefit of that home having a Hi-Velocity System installed, especially if it’s a larger home. Would simplify the Supply Duct system with the thinner wall/ceiling areas available in a MH.
Because of less negative static pressure in the plenum.
In the old days the gap at the bottom of the door was used to allow air to return to the unit. Now they use a jumper vent to connect one room to another. It offer better air flow with less resistance. The small duct in the air filter compartment is for make up air. Make up air is required on houses with tight construction or lot’s of kitchen, bathroom fans etc. This is designed to “make up” the air that is exhausted by the bathroom fans for instance. The make up air duct usually exits out the gable end of the house and would not have a damper.
Older houses also had transom vents or windows above the doors to improve circulation. However, they became unpopular due to the lack of privacy.
Most late 20th century houses do rely upon that gap underneath the door, so if that gap no longer exists due to flooring height change or thick carpet installation, you really should call it out as a minor issue that is causing reduced air flow to that room and making the HVAC less efficient.
My understanding that jump ducts are necessary to get the guarantee low airflow resistance from registers to the return needed to achieve a “green building” label for the home.