High Efficiency Furnace - ductwork changes needed?

[Christian Fox]

Hi,

I'm planning on getting a high-efficiency natural gas-fired furnace to replace our current 15-year old standard-efficiency furnace within the next year or so.

I've heard that the high-efficiency furnaces require different ducting, and use a vent on the side of the house rather than a chimney as an exhaust.

Our current furnace has two insulated ducts going to the side of the house, and the chimney running to the roof. If I get a new high-efficiency furnace, is it likely that the ducts to the wall will need to be changed?

The reason I ask is that I'm considering finishing my basement, and if I do the ducts won't be easily accessible. If the ductwork will need to get changed or replaced, I'd rather do that before finishing the basement ceiling.

Thanks in advance for your help!

Christian Fox

[Noon-Air]

We can't *see* it from here, your best bet is to call your local,

*competent*, licensed, insured, professionally trained, HVAC technician to assess your needs and properly install a correctly sized furnace for your maximum comfort and minimum utility bills.

[Greg O]

Generally you can use the same duct with a high efficiency furnace, but that is not saying your current duct work is correct! Get someone in the trade to look over you ducts and give you an evaluation. Greg

[Christian Fox]

Read my original post. I'm not getting a new furnace right away. I'm finishing my basement right away. I don't want to cover up the ducts, only to find out that they need to get changed after the basement ceiling has been drywalled.

So, I'll simplify the question: Can a high-efficiency natural gas furnace use the same ductwork as a 15-year old, standard-efficiency furnace?

[Christian Fox]

The post was on-topic for both alt.home.repair and alt.hvac, so I posted it to both groups. If you don't like it, killfile me or the thread.

[PrecisionMachinisT]

Opinions are like assholes......

Now, please do explain your motivation in continuing with the cross-posting, if anything other than an attempt to behave as one......

On second thought, don't bother with responding to me--appears you're just yet another troll to place into the bozo bin for the time being....

[Noon-Air]

I'll simplify the answer... I can't *see* it from here.... and I don't know if the system was sized and installed correctly in the first place. Now, as far as finishing the basement *before* you have the HVAC work done, you are putting the cart before the horse. There is a reason why the HVAC techs and installers work their magic *BEFORE* the sheetrock goes up.

[buffalobill]

you will perhaps reline the chimney to the roof. you may be resizing or replacing the wall pipes.

ventilation. gas dryers versus electric clothes dryers. bring electrical connections to the basement ceiling surface. don't bury any pipe connection shutoffs. finishing a basement is a great big project best discussed with a building inspector. a friend of mine added a beautiful and convenient basement bathroom only to face a toxic mold cleanup just a couple of years later related to drips and condensation on a water line. sewage. drainage. radon. legal windows and egress. alarm systems for CO and smoke. moisture arguments of seepage vs condensation. discovering that a dehumidifier is just an air conditioner with a drain hose.

[..p.jm]

Do not cross-post to alt.hvac

Click here every day to feed an animal that needs you today !!!

Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' 'With sufficient thrust, pigs fly just fine.' HVAC/R program for Palm PDA's Free demo now available online

[FDR]

alt.hvac is comprised largely of assholes who donn't know anything about hvac anyway, but likely screw their customers by acting like they know everything.

[Amun]

What a silly person. Imagine posting a question about a furnace installation to alt.hvac

What could the OP have been thinking ?

AMUN

[Joseph Meehan]

There is no specific reason you would need different distribution ducting. However you may want to have what you have inspected and evaluated as many homes have a poorly sized and designed duct system. You can do that anytime. If you are adding A/C then you are likely to need some adjustment. A good duct design can make any system perform better giving you more efficiency and comfort.

It is likely you will need a new intake-exhaust for the new furnace. That depends on what you get. Generally they are easy to install and should not pose a problem. If you are doing work now, you might want to plan. The problem is who knows for sure what you will need for next year's equipment?

If it were me, I would have a pro take a good look at the existing duct system and offer you suggestions about what you may want to do now. Consider zoning as well. Now is the time to consider that.

[Stormin Mormon]

Yes.

Side note, drywalling a cellar ceiling makes every future repair project much harder. Drop ceilings with ceiling panels are much easier for service guys. If you drywall the ceiling, you may well regret it later.

[Greg O]

Yes, if your existing duct work is adequate, but it may not be. I would not bet on it, you may have crap for duct right now! Does that clear it up?? Whether you do it now or ten years from now the answer is the same. We can not see it from here. Get a local to look it over now, before you remodel! Greg

[B-Hate-Me]

Let me tell you something, you gay, homosexual fanny pirate. You just flat out suck dick. On top of being a mormon, the stupidest of all the f****ng stupid religions, you are a fraud and a hack.

Do the world a favor and kill yourself......NOW.

Do It.

PS- You f****ng h*mo.

[Sherman]

I would seriously consider replacing all the duct work with new higher R-Value duct work. My local home depot has several choices for R-value for their flexible duct. Spend some money now and with gas prices tripling, you will be handsomely repaid.

The furnace you choose will have specific venting requirements so just read the documentation that comes with the furnace. Many of the furnace installation docs are online so check their web site.

a vent on

ducts

replaced, I'd

[FDR]

The truth that you are assholes must hurt.

[Joseph Meehan]

I recommend avoiding "flexible" duct whenever possible. It insulates OK, but it does not have good air flow.

Ductwork in a conditioned space like interior walls or floors, does not generally need insulation.

For those installations were flexible duct is unavoidable and where the ductwork will in an area that is not conditioned, then I definitely should be insulated.

[Tekkie®]

Christian Fox posted for all of us... I don't top post - see either inline or at bottom.

use a vent on

the ducts

replaced, I'd

Maybe... and you're welcome

[PrecisionMachinisT]

For the time being....

Makes pefect sense to me--in your continued cross-posting, this makes you almost like one of us--welcome to the club, then !!!

Any other reason for you keep cross-posting this f****ng shit ???