Hi All,

I have a 42 year old bungalow in Southern Ontario with a finished
basement (though the basement was most likely unfinished when the house
was originally built). The warm air ducts on the main floor are all
located at floor level around the outer edges of the house, under every
window. In the basement however, the ducts are in the ceiling and
located in the centre of each room. Each floor has return ducts
located at floor level near the centre of the house.

I'm wondering why the basement ducts are located in the centre of each
room and not the outer edges, like the main floor. Is it because
they're in the basement? in the ceiling? was it just simpler/cheaper to
do it this way? It seems to me that placing them in the centre robs the
outer half of the room from some warm air flow since the warm air would
enter the centre of the room and immediately flow towards the return
air ducts in the centre of the house.

Where possible, I'd like to move the basement ducts from the center of
the room to the outer edges. I'm hoping this will help mitigate some
cold spots that seem to exist near the outer edges of the basement.
Before doing so I'd like to hear if anyone knows any reason not to do
this. I'm worried that they were placed in the centre for a reason and
don't want to find out the hard way why.

For example, the outer basement walls are uninsulated, and covered with
panelling. Would placing the heating ducts closer to the outer walls
increase the likelyhood of warm air condensing on the cold walls in the
winter?

Thanks in advance for your help.

I'm wondering why the basement ducts are located in the centre of each
room and not the outer edges, like the main floor. Is it because
they're in the basement? in the ceiling? was it just simpler/cheaper to
do it this way? It seems to me that placing them in the centre robs the
outer half of the room from some warm air flow since the warm air would
enter the centre of the room and immediately flow towards the return
air ducts in the centre of the house.


It was probably just easier, and I don't think the air-flow patterns
are likely to match what you're expecting. Unless you're getting
fairly high-velocity air flow, coming out a nozzle aimed at the
returns, what should happen is that the warm air comes out of the
supply, and billows out across the ceiling, forming a warm air
layer that slowly lowers as cold air gets sucked out at floor level.

your poor heating is also due to insufficient insulation. the basement
needs a separate heating zone including powered dampers and another
thermostat control.
look up the costs of making a below-grade basement comfortable in
winter versus easier living in the habitable areas of the home.
please first see:
http://www.buildingscience.com/resources/basements.htm

Thank-you both for your replies. I found the link to
http://www.buildingscience.com/ especially useful. What a great site!

it would be best if you can insulate the walls. also,make sure your
funance has the capacity to handle the extra sq. ft. finally if you
move the main trunk you might be making very long runs to your existing
rooms up stairs which will effect you air flow.