On 7-Jan-2004, "lbbs" wrote:

I hear that there is such a thing as heat-recovery unit that can be
installed on a furnace. Are they practical for the average home, in
order to shave money on heating? What is involved, cost, installation,
where can you buy it, how long before it pays for it self?

Heat recovery ventilators (HRV) are used for recovering heat from
ventilated air.

Centralized units don't go on your furnace, but are usually near it.
They are meant for homes that are well insulated and sealed airtight.
All air coming into the house passes through the HRV and is preheated
(if cold, precooled if hot) with the air being vented out of the home.
You have to have a home that has a complete ventilation system, not
just a heat transport system.

Recovery is advertized at up to 80%. This is certainly better than having
a leaky house with all air exchange yeilding 0% recovery of heat/cooling.

There are also HRV units designed to add to a single room. They are
mounted in the wall (sort of like an air conditioner) and allow for
air exchange for that room.

Single room units are sold at big-box stores like Home Depot for about
US$500 or so.

Not sure on how much a central one will cost, esp with installation etc.

Mike