[oVeRdOsE.]

hate air furnace system :

- take space
- wind factor (air speed = more convection losses on your body = less comfort)
- Same principle as above, wind factor create a air flow in front of cold surface (windows walls) and increase the heat looses.
- move dust
- cancel air stratification
- noise
-maintenance
- most system you can't do zoning, 1 thermostat (even if you have manual dampers, T°out will always varies)

Pros are :
- cheap to buy and operate
- easy to combine with a heat pump for cooling and heating. On heating side you can have a nice coefficient of performance (COP - 3 and higher) .


So if you look at ASHRAE 55, its says :
- 50% of the comfort comes form surfaces T° (radiation)
-Then air movement (lower better in heating time)
- Then humidity
- then only 6% comes from air temperature.


That been said, this is why air forced system are not so great for comfort.

here what I like to design :

- Great air ex-changer to move the air slowly and having around 0.1 to 0.5 ACH.
- AC Split unit in a specific spot and near the air ex-changer return.
- heating floor. So here you can go electric, but water is best since you can combine it with a heat pump .
A lot of people think electric heat floor is not efficient, because 1kw power = 1 kw heat(or less), but since you have less air movement, more T° on surface (ASHRAE 55), you wont need to heat the ambient air as high
- All heat floor with a independent thermostat = zoning.
- Where you cant use heating floor, I use convector systems. Well , they are like baseboard , so about same efficiency, but move the air a little bit faster with natural convection.

With all this, I have a 1400 ft2 bungalow from 1959, montreal , 22°C occupied, 20.5° not occupied, everything on smart , even the air ex-hanger, and able to get 2000$ bill / year. No gas, garage is heated, pool too, and we are 4 in the house.

Now the number, pay back might be far away with a water system. But one thing you need to see, if the value of the system. I swear, people are ready to pay more for great systems in nordic countries. Also electric floor are cheap, at least for me , since I have contact. This is a simple system, and people should'nt pay prime prices of the contractors