Best place for new furnace?

[simmer2]

I have a 100 year old house, had a 20 year old furnace replaced with the Goodman brand and I ended up getting a Mid-Efficiency 70,000 BTU furnace. My place is 1,200 sq ft so I would think that would be enough for you.

I would guess you could get the furnace + install for around $4,000....$5,000 is starting to get a bit pricey IMO.

[I-Hate-Hulse]

Originally Posted by simmer2

I have a 100 year old house, had a 20 year old furnace replaced with the Goodman brand and I ended up getting a Mid-Efficiency 70,000 BTU furnace. My place is 1,200 sq ft so I would think that would be enough for you.

I would guess you could get the furnace + install for around $4,000....$5,000 is starting to get a bit pricey IMO.

I just had a furnace tech over 20 minutes ago and he was saying the problem now is that by law mid eff furnaces are outlawed. Therefore you have to get a high eff furnace in as they can't buy them to install.

So that's normally 4,000-5,000 to do but the problem is the new ducting can hit $3,000 for the new ones required for high-eff. Therefore making this a lot more than you wanted.

He said the best thing for now is to try and make your mid-eff last as long as you reasonable can.

[supadaveo]

Originally Posted by 4X4

I'm no furnace pro, but I was under the assumption that BTUs was essentially heat output. So in theory, you'd want the same BTUs. It'd just require less energy to produce those BTUs. Same BTUs, lower energy bill.

This line of thinking is not right. A home needs to be evaluated for its potential heat loss. Iv installed hundreds of furnaces (thats the profession im in) and its been my experience that many older homes had furnaces that were very oversized for the house

[supadaveo]

Originally Posted by Ducay

Well then, the internet has lied to me. The website I was reading was discussing how a 95% efficient 80,000BTU furnace would yield 76,000BTU. The 80,000BTU was essentially the BTU's inputted. Anyways, I guess that's wrong.

You need to watch those numbers you get off the internet, those furnaces are rated at sea level..... Here in calgary that furnace must be de rated by 10% in order to have an accurate heat output

[jeffh]

I am a Journeyman Sheet Metal Worker. I would like to help end some of the speculating on here. First off, if you can get your hands on a mid efficient than you are a lucky person as they are no longer being produced, some small stock-piles are probably still out there. In my opinion high-effeciency is the way to go. Your initial costs are definetly going to be up there for numerous reasons. Your original venting will be over-sized for your hot water heater and will thus need a new stainless steel liner to be installed inside the old one, unless you opt for a new high eff hot water heater as well. New PVC venting will need to be installed for your furnace(s). This may require a hole or two to be cored through your foundation, especially in much older homes. Also the high efficiency furnaces are more expensive than the mid's. A heat-loss calculation is a good idea, but simply going by square footage of your home for furnace size is still a pretty safe and simplest way to go. My personal preference for brand names are Lennox/Armstrong and Carrier, but they are all getting to be quite streamlined. For comparing efficiencies of furnaces, go by the AFUE rating. Hope this helps.

[sclitheroe]

Why do high efficiency furnaces need changes in venting, and why specifically PVC piping? I've tried googling it, but nothing so far..

Edit: found the answer. High Efficiency furnaces extra so much heat from the exhaust that you'd end up with condensation forming in regular flues, and that condensation, because it has combustion by-products, is corrosive.

[Ducay]

So wait, why would you need to core through your foundation? Is the exhaust coming out at ground level instead of up the stack?

[amorak]

Originally Posted by algernon

Don't just consider the high eff, get it or you'll be breaking the law. I think they became code last January. I think Everlast is a furnace guy, you could try him.

Poor Ducay, did you get cut out of the inheritance? I mean, Amorak has a summer home, new Mustang, and you have a busted furnace. That must suck.

haha I think I took that too personally. No inheritance, just hard work and never stepping foot in Dover Going to Dover will mess you up!

[Ducay]

Looks like I'm going to try and have a couple guys come in over the next couple weeks to give estimates. I look forwards to them each having a different opinion on ducting and the exhaust

[amorak]

Originally Posted by Ducay

Looks like I'm going to try and have a couple guys come in over the next couple weeks to give estimates. I look forwards to them each having a different opinion on ducting and the exhaust

Make sure you create a hilarious bidding environment - Have them all over at once for an auction on your business!

[sclitheroe]

Originally Posted by Ducay

So wait, why would you need to core through your foundation? Is the exhaust coming out at ground level instead of up the stack?

Yes, I just posted the results of my research about this.

[amorak]

Originally Posted by sclitheroe

Yes, I just posted the results of my research about this.

Yup - I have a High Efficiency Furnace, comes out the side of the foundation.

[jeffh]

Originally Posted by Ducay

So wait, why would you need to core through your foundation? Is the exhaust coming out at ground level instead of up the stack?

Yes, high-efficient's are direct-vented and are designed for side-wall discharge. As well, the combustion air for the appliance will be roughly through the same opening. Older homes have the foundation end at the main floor and the joists are set entirely in concrete.

[I-Hate-Hulse]

Originally Posted by jeffh

Your original venting will be over-sized for your hot water heater and will thus need a new stainless steel liner to be installed inside the old one, unless you opt for a new high eff hot water heater as well. New PVC venting will need to be installed for your furnace(s).

1) Are Furnace and Water Heater T-ed into the same exhaust line?
2) Rather than installing PVC for the Furnace Exhaust line, can you install a non corroding liner for them?

[simmer2]

Originally Posted by I-Hate-Hulse

I just had a furnace tech over 20 minutes ago and he was saying the problem now is that by law mid eff furnaces are outlawed. Therefore you have to get a high eff furnace in as they can't buy them to install.

So that's normally 4,000-5,000 to do but the problem is the new ducting can hit $3,000 for the new ones required for high-eff. Therefore making this a lot more than you wanted.

He said the best thing for now is to try and make your mid-eff last as long as you reasonable can.

I think I got the terminology wrong...my 95% efficient furnace would likely be classified a High-Efficient...I think you can get furnaces which are 96 or 97% efficient.

[jeffh]

Originally Posted by I-Hate-Hulse

1) Are Furnace and Water Heater T-ed into the same exhaust line?
2) Rather than installing PVC for the Furnace Exhaust line, can you install a non corroding liner for them?

1) Yes, usually they are both tied into the same commen vent and exhausted out a stack to your roof.

2) I don't know, but I'm sure PVC is going to be the cheaper way to go. Plus the usual termination for the outside air and exhaust air is designed for PVC.

[I-Hate-Hulse]

Originally Posted by jeffh

1) Yes, usually they are both tied into the same commen vent and exhausted out a stack to your roof.

2) I don't know, but I'm sure PVC is going to be the cheaper way to go. Plus the usual termination for the outside air and exhaust air is designed for PVC.

I guess I'm wondering if there's a way to use the existing roof exhaust and run some sort of non corrosive liner up it (in conjunction with a new hi E water tank). This way it seems like you would save the higher costs of coring and installing a side PVC vent on your house.

At least it seems cheaper in my mind...

[jeffh]

I kinda figured that was your thoughts. But I don't believe high efficient's are designed to exhaust out a roof stack as the temperature of the exhaust gasses is much lower. Besides getting a hole cored shouldn't cost more than $200. Stainless steel(non-corrosive) liners will run you about the same. Another thing is you will want to direct vent the outside air for your new furnace anyways. And then remove and cap your pre-existing combustion air well...which is a heat loss.

[Ducay]

Originally Posted by jeffh

I kinda figured that was your thoughts. But I don't believe high efficient's are designed to exhaust out a roof stack as the temperature of the exhaust gasses is much lower. Besides getting a hole cored shouldn't cost more than $200. Stainless steel(non-corrosive) liners will run you about the same. Another thing is you will want to direct vent the outside air for your new furnace anyways. And then remove and cap your pre-existing combustion air well...which is a heat loss.

But if you've still got a traditional water heater, wouldn't you still need your existing stack and combustion air intake?

[amorak]

I'd replace both at the same time. My HE water heater and HE furnace together give me a heating bill of half that of a comparable house in size from the 80's you know of. It's like $100+ bucks less a month. UPGRADE!