New Furnace -- Air-to-air exchanger?

[julvr]

I'm looking to get a new furnace. We had the local gas company come in to look at things, and he was suggesting a high-efficeincy furnace that had an air-to-air exchanger. The furnace is rated at 93%, but my understanding is that that is how much of the propane heat gets into the air. With an air-to-air, I would think that I would then have more air to heat, and thus need more gas. I know that an air-to-air exchanges heat between the 'old' air and the 'new' air, but does anyone know how efficient the exchange is???

Also, the gas companies quotes seemed high. Does anyone know of anywhere in the Ottawa area to get good rates on furnaces?

Thanks,

John

[barry]

Bottom line: you need continual exchange of outside air with inside. With a really tight, efficient house, such a heat-exchanger is the way to go.

Dunno typical exchange efficiency, but I wouldn't consider any but counter-flow. Usual trade-offs apply, of course: $ for size, materials, engineering (efficiency.)

J