Is it better to have supply vents on the floor or ceiling in a Toronto home?

For most GTA homes that rely on both heating and cooling, floor-level supply registers remain the better choice for the main and upper floors, because Toronto's climate demands strong heating performance for five to six months of the year. Ceiling supply registers work well for cooling-dominant buildings but create comfort problems during our long heating season, when warm air delivered at ceiling level tends to stay high rather than mixing down to the occupied zone.

The physics behind this are straightforward. Warm air is lighter than cool air and naturally rises. When a floor register delivers heated air at ankle level, it rises through the room and mixes thoroughly, warming the entire space from bottom to top. When a ceiling register delivers that same heated air, it hugs the ceiling — the warmest air stays 7-8 feet above the floor where nobody feels it, while the lower portion of the room remains cool. You end up cranking the thermostat higher to compensate, wasting energy. In a typical two-storey GTA home during a -15 degree January cold snap, this temperature stratification can mean a 4-6 degree difference between floor and ceiling level.

Cooling is the opposite story. Cold air from the AC is heavier and naturally falls. Ceiling supply registers drop cool air downward through the occupied zone, providing excellent cooling performance. Floor registers push cool air up, which also works but is slightly less efficient for cooling because the air must overcome its natural tendency to stay low.

The ideal GTA configuration for homes with both heating and cooling is floor-level supply registers positioned beneath windows on exterior walls. This placement creates a curtain of warm air that counteracts cold drafts radiating from window glass in winter — critical in older Toronto homes with single-pane or aging double-pane windows. The supply air washes up the cold window surface, neutralizing the draft before it reaches the room. For cooling season, floor registers deliver adequate performance as long as the system is properly sized and registers have adjustable louvers that can direct airflow outward into the room rather than straight up against the wall.

Ceiling supply registers make sense in specific situations: basement apartments or finished basements where floor registers are impractical, commercial-style open-concept spaces, or homes with radiant floor heating that handle heating separately and use a ducted system for cooling only. In newer GTA condos and some modern townhomes, ceiling or high-wall supply registers are standard because the ductwork runs through the ceiling assembly — these buildings typically have better insulation envelopes that reduce the stratification problem.

Return air placement is equally important and often overlooked. Returns should be located on interior walls, away from supply registers, to create good air circulation patterns. In multi-storey homes, having returns on both upper and lower floors — with high returns on upper floors and low returns on lower floors — dramatically improves airflow and comfort. Adding return air to bedrooms that currently rely on a single hallway return costs $300-$800 per register and is one of the most impactful comfort upgrades for GTA homes built before the 1990s.