The size of the duct is 8 inches or so - we have 17 heating vents and 7
air intakes - though some are joined in the system. Should I
add vents or intakes or make the plenum bigger - have people
10-15% increase in fuel consumption?!?! wow that defeats the
whole purpose. for us in Vancouver, the temp outside is 1-2 C
colder while we have inside temp 1-2 C warmer, also my wife
is on maternity leave so the heat is on all day as well....with all
this the fuel consumption is up about 70% - I think it is a relative
savings from last year.
The setting for the ramp is the slowest (takes the longest is go
to max.). 2 wires for the inducer - if it is a dc motor it only needs
2 wires and is controlled by the main board.
As for hiring a professional - I have been renovating this house
for the past 2 years and any professional work has been hit or
The ramp setting is for cooling only, has no effect in heating.
Wife being home will raise the fuel consumption.
Can't tell if you should add more returns and or supplies with the limited info.
Adding returns never hurts, doesn't always help though. Almost can't have too much return.
Have a static pressue test done when its at 100% modulation, that will tell you if you need more of either or both.