Why are new "high effeciency" furnaces cooler than older ones?

We bought a new house and I have noticed that the heat coming from the furnace (our of the vents) is noticably cooler than the heat from the furnace in our previous 10 year old house… I would guess by a good 5C at least!

Its a quality furnace (a Trane). I called my contractor that installed it and he said it is “normal with all these new effecient furnaces.”

It sounded odd to me, so I asked a co-worker that just bought a new home as well, and his was indeed cooler than his old one too (he has a Lennox furnace).

Why is that? I would have thought that a high-effeciency furnace would be hotter instead of cooler, so now if anything, the furnace has to run longer to heat up the house.

According to this site,

Thanks! It almost makes sense!

it is easier to tyransfer heat to a cooler airstream then a hotter airstream. by running more air through and not heating air as much you can get higher efficency

As long as it’s warmer than the current room temperature, it will warm up the room. You can blow a small amount of very hot air or a lot of somewhat warm air to accomplish the same heating. The former is less efficient because much of the heat will be lost before it gets to the room.

As long as it’s warmer than the current room temperature, it will warm up the room. You can blow a small amount of very hot air or a lot of somewhat warm air to accomplish the same heating. The former is less efficient because much of the heat will be lost before it gets to the room.