Need a new furnace

[87browser]

I have been reading lots of threads on this site. What a find for the unknowing consumer!

We are helping our daughter, who has just purchased her first house in Asheville, NC. The house is a 1 1/2 story Cape Cod bungalow built in 1927. The main story is heated by an oil furnace which has maintenance records for many years. I'm not sure how old it is, but the maintenance sticker on the side has a phone number that begins with letters. When the panel was removed, there was visible mold. Given the age of the unit (ancient), an HVAC repairman as well as a home inspector both recommended replacement.

The HVAC man gave a quote for I believe a 95% efficient gas unit, but I do not have the details before me of brand or size. (We had to get through the negotiations and closing first, and needed an evaluation so we would know how to factor HVAC into the housing price -- I will get HVAC details from our daughter). The HVAC man did say that the duct work needed to be cleaned, but was in very good shape, with dampers, etc. The inspector had said the house was maintained better than almost every house he had seen of this age in Asheville.

This unit heats an 1050 sq ft basement and 1050 sq ft main floor, with 1 vent into the 1/2 story upstairs, which is augmented with 2 electric baseboard units and a window A/C. There is also a central A/C unit (Janitrol), but I don't know the size. It is working and about 5 years old.

My question is: Do you have any advice on size or efficiency rating? I do know to get a couple more bids, and evaluate the companies. I do not recall if the man who was out did any testing, since we weren't fixing, but decided to replace. Do we need Manual J testing? Being in the mountains of NC, is the 95% unit cost effective?

Thanks for any advice.

87browser

[Edited by 87browser on 08-23-2006 at 12:42 AM]

[Irascible]

Originally posted by 87browser
The HVAC man did say that the duct work needed to be cleaned, but was in very good shape, with dampers, etc.

Thanks for any advice.Duct cleaners quite literally can't clean all your ducts. The "cleaning" that is done results in temporarily dirtier air and often damaged ducts. System performance is not enhanced, only their bottom line.

Guys will disagree with me passionately. After all, I'm attacking their bread and butter. But it's not even debatable. Both common sense and the few real studies that have been done repudiate any possibility of benefit from duct cleaning, other than that of placebo. See for yourself. (http://duct-cleaning.biz/) Leave those ducts alone. (That's assuming they're big enough for AC. As icyflame points out, they may not be.)

Definitely get a heat load calc. You can look this (http://hphaa.com/services/installation/installation.htm) over if you so desire. Not all of it applies to you since it was written for a different climate.

[Edited by Irascible on 08-23-2006 at 04:05 AM]

[icyflame]

Old homes duct systems was not design for AC. Plan having Ductwork done. You shoud not need to have window units or baseboard heaters augment the central system. Shop for your contractor and let them sell you your equipment. Make sure they do load calculations on the home. :D

[ngore22]

IN asheville i would stay with a fossil fuel type heat like heat gas look for the highest AFUE (Annual Fuel Utilization) its like gas mileage the higher the number the more money you save. Make sure the company does a load calculation, ask for license numbers, check them at http://www.ncliscensing.org, check for liability insurance. Definately change all the ductwork. Duct cleaning is a wash according to the EPA to clean a duct it should take 8-10 hrs and cost over 2k dollars. You can replace the duct system for a little more you may also want to consider installing a humidifier on the system since the heat will be used alot to help keep the humidity levels up in the house. I know this may not help ya being in asheville but you can also go to http://www.fahca.org and it can give you some ideas of what to look for in a contractor.

[florida pe]

In Asheville, I would look at replacing the system with a dual-fuel system, that is an electric heat pump with a gas or oil-fired furnace. The heat pump will provide a/c in the summer and heat on the milder winter days. Furnace will kick-on during the colder winter days. Definitely have the contractor do a Manual J heating/cooling load calc. Also have him do a Manual D calc on your ductwork to determine it's capacity. You might want to also consider putting the upper floor on a seperate zone so it can be congtrolled seperately as multi-story houses never work properly with just one system.

[87browser]

Thank you all for info and links. You answer some questions and suggest others. Definately will check out contractors' licenses. Rethinking duct cleaning. Irascible, I can see where you get your name. Duct cleaning sounds like your pet peeve. More questions:

If we get dual fuel system, can we use the existing heat pump with central A/C unit? We will be getting that unit checked out further in terms of size, condition, but it was working adequately.

Duct work needs some sealing and 1 additional vent opening for basement, but was proclaimed adequate per original A/C guy. But now, of course, we know better what questions to ask. Isn't replacing duct system a huge job? Upstairs is separated out also because it is considered a separate apartment (for rental or visiting parents) with outside staircase, electric meter, phone. I didn't see but one floor vent in the 400 sq ft space upstairs, hence the added baseboard heaters. Window A/C available for renters to be separate, but some cool comes up vents -- comfortable a few weeks ago.

Any comments on % fuel efficiency -- is it worth it to pay for 95%, given the NC mountain climate?

Again, thanks.
87browser

[ngore22]

Yes being in the mountains it is definately going to be worth the 95%AFUE. One option for the upstairs is put in a seperate system if she plans on renting it if planning on using it for visiting parents just put in a zone system possibly it all depends on what you want to do and just getting the contractor out there to look at everything.

[Irascible]

Originally posted by 87browser
Isn't replacing duct system a huge job? Yes it is. Some consider this heresy, but an oversized blower and/or a variable speed blower will compensate for undersized ducts to a point. Personally I always install a blower that's one ton (nominally) larger than AC or heat pump even if I'm installing all new ducts. You can always slow down a blower that's putting out too much, especially a variable speed (they have a LOT of settings). But once a smallish blower is maxed out you have no options.

FYI: Most of these guys slept in English class and have no clue what my screen name means. :D

[jacob perkins]

I didnt read the whole thing. If I am off base here,just ignore me ...or correct my errors,either way...


Originally posted by icyflame
You should not need to have window units or baseboard heaters augment the central system. :D

That is unless you really want or need to.
One of the old timers here at H-talk ( who can remain nameless out of proffessional courtesy ) brags about how well his old house does with a window unit. But then again,that might just be a personal quirk of his. I dont know.

But,for example:
If you need 45000 btu 85% of the season and 55000 btu 15% of the season, then the 10000btu of supplimental really makes more dollar saving sense.Especially if it is already installed...







[Edited by jacob perkins on 08-23-2006 at 02:43 PM]

[hvaccolo]

I used to be completely against duct cleaning, too. Then I was doing a retro at an 80 year old house...new furnace and a/c, some duct work. New homeowners. Cracked open duct and found a big pile (probably 5 pounds) of asbestos insulation from pipes. This was neatly tucked into the main trunk. Now, how long do you suppose that was there? How much of that muck went airborne over the years? How many previous tennants got lung cancer or asbestosis? I recommend to all my customers to get ducts cleaned or inspected at least once when you move in...better safe than sorry.

[Irascible]

An extraordinarily rare story colo. For those homes that have no asbestos wrap on their ducts, and for the rest that were built after asbestos was banned, extraordinarily rare becomes nonexistent. Not to mention that depending on where your pile was, they may not have even gotten to it. The pile was likely in a relatively steady state. Had duct cleaners disturbed it they would have likely loosened a bunch of it up and left their customers breathing a lot of it after the job was done. Duct cleaning is laugably spotty in its results. You want real duct cleaning? Take them apart and hose them down. A supposed 5 pound pile of anything isn't likely to be removed by any method other than taking a duct apart. It'd be like removing a dead cat with duct cleaning. You'd loosen cat bits up but you wouldn't remove the cat.

[icyflame]

[QUOTE]Originally posted by 87browser
[B]
If we get dual fuel system, can we use the existing heat pump with central A/C unit? We will be getting that unit checked out further in terms of size, condition, but it was working adequately.
87browser


You have a heatpump now? with a central AC system?
I just re-read your post...You Now have a fuel oil furnace, you're asking can you add a heatpump to your fuel oil furnace making it a dual fuel system, so you will end up with two heating sources and one cooling source. The heatpump will be your primary heat and it should run 70% of the time. Your fuel oil will run 30% of the time. The heatpump will also run through the summer as the air conditioner. A heatpump is a Central Air Conditioner with a couple of extra parts that allow it to change direction of the flow of refrigerant. (like puting your car in reverse)
So the answer to your question is "Yes you can add a heatpump to your fuel oil furnace"!

[87browser]

Icyflame --

I obviously don't know how to describe things. What I was trying to ask was this: we have both an ancient oil furnace and an existing A/C unit. Can we use some components of the A/C system plus a new gas furnace to make a 2 stage fuel pump/gas backup system?

Thanks, 87 browser

[icyflame]

Originally posted by 87browser
Icyflame --

I obviously don't know how to describe things. What I was trying to ask was this: we have both an ancient oil furnace and an existing A/C unit. Can we use some components of the A/C system plus a new gas furnace to make a 2 stage fuel pump/gas backup system?

Thanks, 87 browser
Gottcha!...Answer is NO...You are getting rid of the oil furnace to put in a gas furnace. That leaves a lineset, and condenser. You're changing the condenser for a Heat(fuel)pump. The lineset should be changed out too.
If you are asking, can you install a new system next to your old system and use the old system as a second stage back up...Well...You can put two systems in tandom BUT I would NOT with an new and old gas and fuel oil ac and heatpump.

[xv80satisfiedcust]

"Take them apart and hose them down".

If I have a crawlspace and asked a contractor to detach the parts at the
airhandler/furnace could this actually be done?

(If the heat was immediately turned on afterwords could this dry the sheetmetal)?

I would think water/fluid would be the only way to thoroughly clean the ducts, or are you just joking?

[comfortdoc]

Originally posted by xv80satisfiedcust
"Take them apart and hose them down".

If I have a crawlspace and asked a contractor to detach the parts at the
airhandler/furnace could this actually be done?

(If the heat was immediately turned on afterwords could this dry the sheetmetal)?

I would think water/fluid would be the only way to thoroughly clean the ducts, or are you just joking?



Not a joke at all. If the ducts are accesible enough for removal and reinstall it's the most thorough way to clean them.

They dry fairly quickly if just left out in the sun. By the time the last is washed out the first should be dry enough to install.

[Irascible]

Originally posted by xv80satisfiedcust
...or are you just joking?I was joking only in the sense that if you actually want to clean your ducts, you need to take them apart. The larger point is that duct cleaning in general is completely unnecessary more than 99.99% of the time. Where it really is needed (rat infestation for example), the ducts need to be taken apart or replaced completely. Duct cleaning as it has manifested is a dog and pony show that serves only to make the air dirtier. That's an irrefutable fact backed by the few legit studies that have been done.

[jim baughman]

Originally posted by 87browser
Icyflame --

I obviously don't know how to describe things. What I was trying to ask was this: we have both an ancient oil furnace and an existing A/C unit. Can we use some components of the A/C system plus a new gas furnace to make a 2 stage fuel pump/gas backup system?

Thanks, 87 browser

If you use a gas furnace along with the a/c you have now, then there is only one source of heat...the new furnace. This will not give you dual fuel capability. If your handler is located under the house in a crawl space, you might consider changing to a dual fuel packaged heat pump unit. A few duct changes and you would have a completely new system operating at current SEER ratings and save money. If the duct work is a problem, then you could always change the a/c unit to a heat pump unit and the new furnace, then you can have dual fuel that way. Hope I am reading your posts right on this. One thing that is very important....INSULATION....old houses did not come with much and that may be a problem with any system.

[options]

ngore22 - What the EPA actually said about air duct cleaning is "'These services typically -- but not always -- range in cost from $450 to $1,000 per heating and cooling system, depending on the services offered, the size of the system to be cleaned, system accessibility, climatic region, and level of contamination. You can also find the entire transcript of this article on the EPA's web site entitled "Should You Have Your Ducts Cleaned." Here's the address:

http://www.epa.gov/iaq/pubs/airduct.html

Also thorough cleaning done by a professional air duct cleaner removes the dirt from all of the ducts, not just those you can actually replace without taking a sledge hammer to the walls and ceilings.

Irascible its been a while since I last posted here, but I see that you haven't lost your passion for bashing duct cleaners! We've had this discussion before and you know as well as I do that there are good and bad in every trade including your own (hvac), but I sure wish you'd get your facts straight about mine! There are a lot of good duct cleaners in this country and we take pride in what we do. We are also often the ones that clean the little things that techs in your field so often neglect. You know those little [i] non-critical [i] parts like the blower, evaporator coil, primary and secondary heat exchangers where dirt built-up on their surfaces not only affects efficiency, air flow and comfort, but can lead to the premature failure of the system!

The EPA has stated that a build up of .042 inches of dirt on a cooling coil can result in a decrease in efficiency of 21%" For those that don't know why, its because dirt is an insulator and it interferes with the heat transfer between the air and the coil. Since this causes the system to run longer and use more electricity, why are there so many systems installed without access panels that would actually enable the hvac tech to clean these and the coil's drain pan and line during their annual clean and checks? (Want to bet this same principle can also be applied to the finned surfaces of the secondary heat exchanger?) You'd also be amazed at the number of complements I get on the noticeable increase in air flow and the reduction in noise after I've removed, disassembled and cleaned a blower in a system that has suffered from inadequate filtration and gone without cleaning for years.

Thorough cleaning, like anything else in life takes quality equipment, time, patience and a desire to do it right. Cleaning methods vary with the type of construction and the area in which you live, but with rare exception (at least here in the northeast) one person can thoroughly clean most residential systems and a potential customer's best bet is to find a company that takes pride in their work.

Beware of advertised "Bargain" prices. These are generally limited to a very small portion of your system and their final price is often hundreds of dollars higher!

References are the single best way to hire anyone regardless of their trade and I highly recommend that you get at least 3 from not only friends and family, but also from local hvac and especially from reputable disaster restoration companies.

Thorough cleaning can't be done in an hour or so, nor should it be ever done with a glorified shop vac. The vacuum used should be capable of moving at least as much air and preferably more than the blower does in the system being cleaned. The rule of thumb for cooling is 400cfm per ton of cooling and while that translates to 1000cfm for a 2 1/2 ton system, I've never clean one even that small with a vacuum rated at less than 5000 cfm. Agitation is equally important and simply sucking the dirt out won't work. Nor will air pressure alone used in combination with the vacuum to thoroughly dislodge the dirt.

Some companies use brushes in combination with a good vacuum, but Please don't confuse this with those that use a glorified shop vac and a vacuum hose with an attached rotating brush! Others like myself prefer pneumatic powered cleaning tools consisting of a variety of whips and air sweeps. I also have a brush system, but in 99% of the cases prefer my pneumatic powered brush and whips to it. The pneumatic brush uses a spinning reverse nozzle to pull itself thru the duct work.

Cleaning flex duct can be tricky and care must be taken to identify its condition prior to cleaning. This prevents it from coming apart either internally or at the connections to the vent and main ducts.

Essential to thorough cleaning is the means used to verify it and for that reason I clean with live video which eliminates guessing when each duct is thoroughly clean. Some companies use before and after pictures and a few offer video tapes of the cleaning, but care must be taken to ensure that what you are seeing is actually your system! I also have a golden rule that anyone present during my work has the right to watch, ask questions and to expect courteous, knowledgeable answers.

Unless removed from the home, rinsed and thoroughly dried afterwards, water should never be used to clean ducts and some household cleaners may leave you with a very unpleasant odor to deal with later.

The EPA regulates the types of chemicals that can be used and they require that all sanitizers be registered and carry a label that identifies their use for each specific application. There are currently no sanitizers registered with the EPA for use in porous ducts such as unlined fiberglass duct work, unlined wall cavities used as duct work and unlined panned returns. I would also suggest that those with chemical sensitivities carefully read the label and material safety data sheet (MSDS) before allowing anyone to apply these to apply any chemical to your system.

[Edited by options on 08-30-2006 at 11:40 PM]

[87browser]

Thank you, Options, for the opposite point of view from Irascible's. I can trule say that I am now confused at a higher level. I will review all of your links, and also look at our ducts. The house is 80 years old, and I don't know if the ducts have ever been cleaned. The furnace and duct work is in a full unfinished basement, walk-out door. The A/C is outside the house, and may have a component inside. Attic is inaccessible right now due to remodel, but we hope to be able to make a new opening to check insulation. We were hoping to be up there now to get estimates and make arrangements, but Ernesto has delayed our trip.

Thank you all again for the help.

87browser

[Irascible]

There's no need to be confused at any level 87. Simply focus on results and it all becomes clear.

In my essay (http://duct-cleaning.biz/) I link to and/or talk about every study that I have ever seen on duct cleaning, including the one (http://hphaa.com/editorials/ductcleaning/epa_duct_cleaning_study.pdf) sponsored by the National Association of Duct Cleaners and the EPA. Non-committal statements from the EPA that sound mildly supportive mean nothing. It’s the results of their and NADCA’s study that count. It showed the air being 9% dirtier after duct cleaning. Other studies have similar results.

As far as coil and blower cleaning goes, please do so if it needs it. I have always acknowledged the usefulness of that.

IF anything has changed in recent years NADCA would be all over it like a cat on tuna. A well done study showing cleaner air would silence me, hundreds of other contractors and even the Washington Post (http://www.washingtonpost.com/wp-dyn/content/article/2005/11/02/AR2005110200676.html). Yet it’s been a decade since the failed EPA/NADCA study and we have nothing from them, not even plans for a new study. Why should they? It's a 4 billion dollar industry based on hope. All the legit studies have quashed that hope. They certainly aren’t going help dig their own grave any further.

[options]

Irascible I think I finally understand where you are coming from and I've taken the liberty of quoting the following paragraphs directly from your website:

"It depends on the company. Companies that just hook up a truck mounted vacuum to your system are accomplishing little. Find a dusty table. Remove the attachments from the vacuum hose and put it directly on the table. Depending on the particular table and type of dust, the only dust that will come off is that which is physically disturbed by the hose itself. Everyone knows you have to wipe dust loose before you can vacuum it."

"That's where the big roto-rooter looking brush comes in. Companies that use one are at least removing some dirt. But they have a problem. That brush is of a fixed size. It has to fit comfortably down the smallest duct it passes through. As branch ducts progress into trunk ducts and get bigger, the brush removes less and less."

"Then they have another problem. Ducts often make sharp turns. As they feed the rotating brush down the duct they eventually come to a point where the brush will no longer go in. At that point they're done. And it's usually well shy of the end of the duct run."

"Then comes the worst problem of all. Many houses, probably the majority in northern California, use what's referred to as wire flex duct. Imagine a big stretched slinky with plastic bonded to it. Wrap that with insulation and then wrap it again with one more layer of plastic and you have wire flex duct. If it's installed near perfectly you have no problems. But it almost never is. Often times the connections are loosely held together with dried out duct tape. And what's worse, there's often cuts and other imperfections in the inner plastic liner. The duct cleaners feed their motorized brush down the duct and RIP! Part of the duct comes apart."


I totally agree with your assessment of that equipment and the methods you describe above, but thought that I've always made that point very clear in my posts when I have described the methods and the equipment that I use on every job. And while there have been no recent studies done, there have been vast improvements made in equipment and in the cleaning methods used by professional air duct cleaners today!

Here's the vac I use every day!
Heat Seal Compact Truck Mount Vacuum
http://www.heatsealequipment.com/dc/us/compacttruckmount.htm

For those times when parking or access is a problem, I use these:
Nikro EC-5000 (3-Stage HEPA Filtered Electric Vacuum)
http://www.nikro.com/products/moreinfo.asp?i=310

20HP General (Gasoline-Powered Portable Vacuum)
http://www.meyermachine.com/

And I do all of my cleaning with these:
http://www.heatsealequipment.com/dc/us/scopionrodpackage.htm
http://www.nikro.com/products/moreinfo.asp?i=300
http://hartshearth.com/productcart/pc/viewPrd.asp?idcategory=99&idproduct=5932
(Believe me - these stainless brushes aren't something that you ever want to run thru a section of flex duct!)

Many larger and a few smaller companies use full size truck mounts like these:
http://www.biltwel.com/
http://www.caddyvac.com/

And ALL of the above are a far cry from smaller portables like this:
http://www.rotobrush.com/
Please note that of the 3 testimonials given on their home page, not one is from anyone claiming to be a professional air duct cleaner!


>>>Edit: Fixed your italics and bold. Benny<<<

[Edited by jrbenny on 08-30-2006 at 10:06 PM]

[options]

My best suggestion to anyone looking for air duct cleaning is to do your homework! Talk to friends, neighbors, co-workers and especially to a VARIETY of trusted professionals in other related fields like hvac and disaster restoration. Please make sure that your final choice is based on reputation rather than name recognition including that of those companies that are NADCA certified!

Beware of low advertised prices too! These are often used as bait to get your call and once in your home, their techs often work far harder at selling you upgrades than they do at cleaning your system!

When you have chosen a company tell them that you expect a written copy of their final price in writing before they start working for you and if you later feel that you've been the victim of fraud, bait and switch or high pressure sales tactics, PLEASE call the attorney general's office in your state and file a complaint!

[options]

Thank you Benny, its been a while since I've posted!

[Irascible]

You can dress a pig in a tutu, be she still won't dance. ;)

If you'd like some agreement from me, then sure: Duct cleaning equipment has gotten more expensive. However, the need to remove the dirt was never there to begin with - at least not 99% of the time. I pulled out a 50 year old residential duct system last year. If it had 3 times the dirt that I saw it still would not have mattered. A thin film of dirt in your ducts affects the air no more than a film of dirt on a table. It's just sitting there, doing quite literally nothing.

I'll take my leave of the thread while we are still congenial. :)

[options]

Originally posted by Irascible

However, the need to remove the dirt was never there to begin with - at least not 99% of the time. I pulled out a 50 year old residential duct system last year. If it had 3 times the dirt that I saw it still would not have mattered. A thin film of dirt in your ducts affects the air no more than a film of dirt on a table. It's just sitting there, doing quite literally nothing. [/B]


Irascible - If this were the rule, rather than the exception, please explain:

Why the furnace filters ever need to be changed in the first place?

Or how so many supposedly reputable hvac companies are able to con consumers into believing that the air passing thru their system is dirty enough to warrant buying expensive add-on components to clean it? And better still why those same consumers often see a major difference in air quality after these are installed?

Or how what you allege to be "clean" air ends up coating the blower motor, the fins on the secondary heat exchanger, and the evaporator coil with enough crud to warrant a service call from a tech that should otherwise be as lonely as the proverbial "Maytag Man!"

The only way that I can think of that the ducts in a 50 year home would remain that clean is if the air handler itself were located in a relatively clean and undisturbed environment such as the attic and that if all of the vents were located in the ceilings. Gravity would then be able to minimize the amount of airborne particulates that would be suspended high enough to enter the system during its operation and it would virtually eliminate any that would normally settle out of the air or be deposited into the ducts during normal living activities. I would also suspect that the doors and windows in this home were rarely opened and/or that the filtration consisted of something far better than the fiberglass filters normally available that long ago.

But that sure isn't the case here at least not in any of the older homes I've been in. For starters, 50 years ago most furnaces used only cheap fiberglass filters if they had one at all. At a 7% to 10% efficiency, their only true function was to protect the blower, not filter the air!

Return vents mounted directly to the floor are very common in older homes and in fact, in many of these the only returns that actually work are those located closest to the furnace. These are often located in or near the highest (and dirtiest) traffic areas in the home - the hallways! Those heavy metal vent covers must be a great place to clean off shoes, because you can literally shovel the dirt out of those vents!

Floor mounted supply vents are common too and they also get their share of dirt, spilled liquids and just plain crud in general! These vents are also a great place for folks young and old to hide unwanted food, toys, illegal substances and some other things I'd rather not mention here.

Most newer homes still have low wall or floor vent openings and some use fiberglass filters. Its only in larger multiple story homes and in some newer additions that we find systems in the attic and yes those systems are generally cleaner than those having vents in the floor or low walls, but there are exceptions even to that rule and we are often called to clean following remodeling projects or when the system was operated while the home was being finished. I've gotten many thank you's from grateful homeowners telling me what an amazing difference there was in dust after I cleaned all of that fine drywall and sawdust out of their ducts!

[Edited by options on 08-31-2006 at 11:50 PM]