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07-16-2005, 06:01 AM #1Regular Guest
- Join Date
- Jul 2005
I am looking for basic info and suggestions to replace a very old gravity feed gas furnace. I would like to put in a new 90+ high efficiency furnace as well as central air. along with the replacement of a 20+ yr old water heater. What questions should i be asking a contractor and what i should be looking for in terms of a new furnace, ac unit and water heater. Brands may be helpful when discussing topics with contractor. Not sure of square footage of home but i estimate about 1600 to 1800 sq ft. with a second floor. I guess the old furnace is called or nicknamed a spider furnace it is very large and takes up a large part of the basement, alteast 6 to 8 ft square which includes duct work which is 12" or 14" round and is vented through the chimney, Ductwork may be asbestos based. I live in michigan and the brick house is roughly 80+ yrs old. Some basic blown insulation has been done in the attic about 20+ yrs ago. and the hot water heater warrenty expired in 1983. so i assumed its more than 20 or 25 yrs old. I have an older parent living in the home and the heating bills are astronomical and the house boils in the summer months. Need to reduce cost do to fixed income and the possiblity of selling home within 10 or so yrs. I know the furnace is over 40+ yrs old, if not older. The home overall is in decent shape with little or no maintenace over the years, basically nothing falling down. The roof may be replaced in the next few yrs as well. I'm sure the furnace has never been inspected. Also what would be a extremely rough cost to replace this system. I am willing to dismantle the old furnace to help reduce cost. Any help would be appreciated, especially features to look for in a new system and questions i should asking the contractor. Unfortunately unable to move parent out of home due to age, economics and basic stubborness....lol Parent has lived in home 35+ yrs.
[Edited by jdprime on 07-16-2005 at 06:25 AM]
07-16-2005, 06:50 AM #2
Prices are discussed on this forum, its against the rules.
Brand isn't of great importance.
You want a contractor that does manual j, and d, to size the unit and the duct work.
When installed right, all brands are good.
07-16-2005, 06:50 AM #3Professional Member
- Join Date
- Oct 2001
- Waterford Michigan
Call a few contractors out for an estimate as they are in a much better position to evaluate your needs. You will also need a new duct system and if asbestos is present it will have to be removed by a licensed asbestos removal company, so be ready to spend some money. I would focus more on the quality of the installation than the brand of equipment.
07-16-2005, 08:26 AM #4
Here's one of ours from years ago before the day of good digital cameras. Asbestos people removed all ducts and asbestos from the furnace. Our guys removed the furnace (and lengthened their arms a few inches).
07-16-2005, 09:24 AM #5
First, why are you wanting to replace it?
Is it because you want to add air conditioning? If so, then thats pretty much it.
I doubt its broke, there is not much to break on it and mark my words, you wont save any on your heating bill. (you might get much better coverage and even comfort which requires more work be done). You've never had a service call to date, yet you want to start?
If you still have a powerpile generator (no power to gas valve) you are in luck come the days of no power. If you upgrade, of course you wont have heat when the power goes out. How about noise? I bet its quiet, other than a dull whoosh when it lights. Now you will have an inducer fan, a blower motor, ducts bangin (if not properly done).
Again, unless your adding air, I wouldnt mess with it. If worst comes to worst a powerpile generator may be hard to come by but 24v conversion is no big deal.
BTW, replace the water heater
07-16-2005, 12:45 PM #6Regular Guest
- Join Date
- Jul 2005
Im looking to replace furnace because of the cost it takes to heat the home during the winter months and to add AC. I think that there will be significant cost savings. When there is a 3 foot ring of gas flame used to heat ur home and its all gravity feed I think there will be a huge cost savings, both in the short and long term. From others that I have talked to they say that a new furnace will pay for itself in about a yr maybe a little more. I have my own home comp to the current situation and I pay nowhere near the cost that my mom pays for her monthly heating bill. It's roughly half the cost. So Im just trying to understand why you would say there would be no cost savings. Please eloborate if possible. BaldLoonie thanks for the pics link, The one we have is about1/3 larger than the one you posted. Also would you agree with docholiday about no significant cost savings.
[Edited by jdprime on 07-16-2005 at 12:51 PM]
07-16-2005, 01:23 PM #7
Ahhh, Doc, how'll we ever make money if we can't sell anything new to this person, and the old thing never breaks down and needs service??
Actually, in our area we still have a few of these octopus furnaces, old coal burners that were converted to oil, then to gas. Most don't burn that efficiently, too much air, too high stack temps, but no-one is likely to adjust too much a system that's been running trouble free for so long.
Lot's of techs have never seen such a system.
Very true, few moving parts, very simple, nice heat when the power goes out.
I wouldn't assume it's burning cleanly, very well worth doing a combustion analysis, checking the chimney, checking the safeties, and checking for leaks aroung the access doors.
True, you can't have a/c, humidification, forced air circulation etc.
On the other hand, silent, reliable, and absolutely no hydro consumption. (Furnace blower is one of the biggest hydro users in the home).
In our area most homes have full basements, and the octopus uses it all up. Often these old systems were replaced so folks could make better use of that space, not because the furnace gave any problem. And yes, to add a/c.
Not to give anyone ideas, but we had a local murder case many years back where the murderer cremated the body in one of these old furnaces!!!
07-16-2005, 01:42 PM #8Regular Guest
- Join Date
- May 2005
- Western Kansas
I've seen a few of those abandoned and pushed off to the side in peoples basements....we tore out a couple, used sledge to break in sections to get it out the door. Someday I'll probably succomb to asbestos because of how careless (and ignorant, because both him and his dad died of lung cancer at an early age...just guessing) the boss was and how green in the business I was at the time. I talked to an asbestos removal specialist and if you ever have to deal with the wrap, be sure and take a sprayer and wet the wrap totally down. Keeps the particles from floating and getting into your lungs.
07-16-2005, 02:54 PM #9
There's still alot of them around here.
As far as not saving on fuel. Haven't had a customer that didn't save enough to justify the change out.
Of course that could be becuse of resizing too.
Had acouple that didn't like the noise of the new one though.
07-18-2005, 12:42 AM #10
Well, there are apparently a few who lurk this site who would love for me to tell you that you should buy two new furnaces and 6 new air conditioners.
Since you want air, as I said before, you got to replace it. That pretty much is the deciding factor so I should stop here.
And dont get me wrong you might just save gas, but if someone promises you savings be sure to get it in writing. Why? Because currently you have a system that heats the house by gravity. It has maybe 8 supplies (close I'm sure) and one or maybe 2 returns all in the floor. You have no way of controlling comfort in the dead of winter becuase the heat exchanger is solid cast iron. Once it heats up it continues to offer heat long after the thermostat satisfies. You have temperature swings of probably 3 or 4 degrees and it is very unlikley that all corners of your home are comfortable. Stratifcation is obviously present.
So the guy comes in, does what he is supposed to do and installs a proper system with new ducts based on manual J and D. He determines he needs a given BTUH at a given airflow to each room. He even heats that bathroom you dont have heat in and the kids room that is freezing. He even heats the whole room, not just the upper half of the room. Well this takes alot more BTU's than you are currently using considering the space is now enlarged. Your savings may be in effiency of the flame but not actual usage. You will indeed be more comfortable but that's simply not a number that will calculate in the bill. You can now have air, but it will not calculate.
Now, you will be running two new motors you never had before, will that equal any type of savings? If so, how? Small motors, but motors you currently dont have non-the-less. And service. I recommend service by someone experienced in those old things. A simple adjustment to the air mixture might increase your efficiency. However, you will need to have the new system serviced on average every 2 years for good maintenece and maybe even a repair or two in 5, after all there are alot of moving parts involved here. Filters is going to be a new expense for you also, you could go cheap and spend 15 bucks a year, you may also end up spending an additional 100 a year.
I say you replace it since you want air. The rest was the elaboration you asked for.
07-18-2005, 05:42 AM #11
So the ones your use to didn't have alot of draft in the chimney sucking alot of air through the furnace cooling the heat exchanger and keeping the chimney hot.
07-18-2005, 12:46 PM #12
Draft takes a long time to cool 200 pounds of solid cast iron. In the dead of winter its a non issue. In the mild times it may but in my humble experience folks with these furnaces, dont fire them in the fall till much later than the rest of us and shut them down in the spring long befre the rest of us. The comfort is subjective since we are all used to different standards.