Newer more efficient gas furnace have much smaller blower motors?

[Norm]

  I couldn't help thinking if only I had a smaller

motor that ran the furnace blower...I could run

the furnace with a lot less current.

  The furnace that I have is a gas furnace 40

years old, originally it had a 1/5 HP. motor

It now has  a 1/4 hp.

driving a squirrel cage blower belt drive....

It has an adjustable ratio pulley on the motor

that can be adjusted from 3/4 inch to 3 inch

the blower has a 6 inch pulley.

   At the present time it is adjusted to 2 1/2

inches.

    I experimented with it one time...it can be

switched to CAC (Constant Air Circulation) then

I adjusted the variable ratio pulley to  1 inch.

    I liked it but I was concerned that it used

too much electricity that way. It was quiet at

that slow of a speed but the wife could barely

hear it and so she didn't like it.

    Anyway I would like to know what size motors

they have on the newer efficiency furnaces.

    This furnace heats an 864 sq.ft. house

( 24 X 36 ft.)

     Mainly I want to know the smallest size

inverter I would need if I had a newer furnace

installed. I'm getting a 700 watt inverter from

Sears ...If that is big enough my  requesition

slip is more likely to be approved by the 'Boss'

Thanks for any help

[TomW]

Gee, Norm;

Why not go direct off batteries?

Just wondering if you could set up a bunch of muffin fans in a flat pack to push air around?

Some are very efficient, quiet and cheap. Run off DC so no need to run an inverter and all the issues with that.

Another option might be cooling fans for vehicles? They usually suck at efficiency, I think, however.

Just thinking out loud.

TomW

[kurt]

newer furnaces have multi speed usually 3 motors of about 1/2 hp plus a 1/8 hp or so vent blower motor plus glow bar ignition that draws 300-400 watts for a minute or so every time the burner starts some models use spark pilot ignition and that uses allot less power but most use the glow bar these days.... o and when you find that your furnace don't work on a cold winter night it is usually that glow bar they are not very reliable.

[scottsAI]

Hello Norm,

Newer furnace can have variable speed blower motors. (many not just 3 speeds)

Can be set for Constant Air Circulation using about 40watts.

The burners are also variable BTU output.

When the burner is on the blower speed goes up depending on how much heat is needed. Top speed fan blower power is around 200watts. Make sure the blower has actual air foil bladed blower fan. Many have bent metal, which use about 30% more power for the same air speed.

Of course depending on the manufacture the above numbers can be all over the map, the above represent the best I could find. A furnace with these features cost more than one without... so you will have to decide what is the lowest system cost for you. Hopefully your in the market for a new furnace? Otherwise this is another system expense.

I would rather look at solar heating than a gas furnace...

Or use a gas tankless hotwater with an A frame for heating and hotwater, just might be overall lower system cost and much easier to add solar heating in the future. Efficiency is almost as good, the tankless hotwater is much better than most.

Have fun,

Scott.

[ghurd]

A fresh new filter makes a big change in

the blower power needed too.

I wouldn't be comfortable with 700W from Sears.

Might consider the 100AH near the furnace,

charged by the van with long jumper cables?

Just for that once ever couple years.

G-

[Chagrin]

Yeah the newer ones are DC motors. Something to look forward to.

Working as an HVAC installer must be like used motor heaven.

[Norm]

Yes it's from Sears and it's a clearance item,

so that should tell savvy people something ..Eh?

[Norm]

Yes I have 2 openings in the bonnet where the

return air goes....one in the hallway that is

about 10 x 18 inches....just had a thought about

using 2 window fans blowing into the hallway

from the front room and closing the utility and

bedroom doors.

Make a special door to fit the 2 fans into and

put in the hallway door opening into the front

room, the 225.....max 400 watt inverter

runs one fan that I know of...it could perhaps

run 2?

 Could possibly work....Thanks for the start in

the right direction..It would be doable even for

me....LOL !

[Norm]

Thanks Guys info from all of you has been very

helpful.

BTW The swing project is still an ongoing project

even tho its impossible to swing right now with

snow drifts up over the seats!....too much drag !

     LOL !!