From: "Phil Scott" 
Newsgroups: alt.home.repair alt.building.construction misc.consumers.house
Subject: Re: Single stage vs. dual stage furnace
Date: Thu, 12 Jan 2006 11:40:02 -0800


"Harry Muscle"  wrote in message 
news:1137092408.033428.181800@f14g2000cwb.googlegroups.com...
> I'm in the process of deciding which furnace to get to 
> replace my
> existing furnace which is ready to die.  I've been told that 
> high
> efficiency furnaces are not really worth it since they cost 
> more up
> front and they cost more in repair costs in the long run so 
> in the end
> high efficiency vs normal efficiency will have cost about 
> the same, but
> the high efficiency will have broken down more often due to 
> it's
> complexity.  This makes sense ... but I have one more quick 
> question.
> Are dual stage furnaces quite complex and prone to break 
> down also?
>
> I've thinking of maybe getting a 80% dual stage furnance 
> which would be
> a bit more efficient than a single stage 80% furnance.  But 
> I'm
> wondering if it's worth it.  Would a dual stage 80% furnace 
> be as
> complicated as a 90%+ furnace?  Are the parts just as 
> expensive to
> replace/repair as a high efficiency furnace?  Or in other 
> words should
> I stay away from dual stage furnaces for the same reason I 
> would stay
> away from a high efficiency furnace (high repair costs, 
> higher chance
> of break down).
>
> Thanks,
> Harry


Id go with a single stage 80% furnace myself.

If you really want to save money install two systems...one for 
the night time sleeping areas, and for the day time living 
areas... install set back thermostats on each system so the 
HVAC gets set high in bedrooms during the day, and the living 
areas get set low at night (these settings can be easily 
overridden when needed)

If you want to save more money, fit matress warmers to your 
beds, and you can set the temp to 50F at night no problem.

Be sure to undersize both systems slightly..they operate more 
efficiently when maxed out.

Install the furnaces in places where they can be yanked out 
with great ease so maintenance is not a problem.    Insulate 
the ducts well, tape all the seams and flanges well, use duct 
seal in a caulking tube.

Rheem makes a pretty good unit these days.  but brand is not 
as critical with furnaces as with some other items.







Phil Scott
HVAC contractor/ mech engineer since 1911





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