Has anyone ever replaced their conventional furnace fan motor with an ECM motor?

Hi, This type motor is known for failure mode for motor and controller going out together. Most people who has this thing in their furnace, they take out 10 year warranty for that part. If you buy and use it as constant speed blower at an expense, that is fine for the purpose of experiment but economy wise I don't think you'll recover initial cost and if it fails......

Reply to
Tony Hwang
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I would agree with the above definition.

In the case of, say, a furnace, there is a complicating factor that the owner is not usually the one that makes the decision that the item needs replacing. He is being coerced into that decision on the advice of someone who has an interest in selling you a replacement.

In other situations, the complete failure of a product is more clearly visible to the owner, and he or she can go remove and replace it without relying on a third party.

But getting back to furnaces,

If 30 years ago you had one part in a furnace who's mtbf was 20 years, and when that part failed then the most practical recourse was to replace the furnace, well in some cases you will get 15 years before failure and in others you will get 25, even 30 years before failure.

Today, if you have 3 or 4 critical parts, each with an MTBF of 20 years, then the odds are higher that the furnace will fail at 10 years because you have 3 or 4 critical parts and the failure of ANY ONE of them means the failure of the furnace.

A 20-year warranty on the heat exchanger is meaningless if you will still have to pay $1000 for labor to replace it, and the contractor or repair guy is telling you he'll sell you a new furnace for $2000. Is that a situation that a homeowner wants to face? Will he feel good about making the decision?

Wouldn't it just be easier to add a few more oz. of stainless steel to the heat exchanger design and have an exchanger with an mtbf of 50 years?

And besides, with houses better insulated today, you don't need a million BTU output furnace. With constant (or near constant) run times, furnaces can put out lower BTU's constantly and are avoiding hot/cold cycling. Our knowledge of metalurgy and alloys is better today, the demands on a furnace are less today than they were 30+ years ago. So it's practically criminal that a heat exchanger is only warranted for 20 years these days.

The furnace that does in the typical new house is not chosen by the first owner - it's chosen by the builder.

The first owner of a new home, if given the opportunity, is more likely to pay attention to ANYTHING going into the house's construction vs any future owner of the house.

It would be nice if there was, or could be, some sort of communications channel directly between a new home owner and a furnace manufacturer, such that the home owner knew that he had the option of paying $500 more for a furnace that would last 35 years vs maybe 20 years, and if the home owner could convey that decision to the home builder, and if the builder didn't gouge the owner and charge him $1500 extra for that furnace.

In the case of a furnace, the market has no expectations because the market has such little exposure to or life-experience with the product. It's hidden down in some dark corner of the house, mostly unseen.

Look at cars. People become intimately familliar with their cars. Cars are vastly more complicated, and put to more demanding use than furnaces. Cars today easily last 15 years - most of that time the car is no longer under any warranty so repair costs must always make economic sense vs buying a new car.

What we have in cars is a setup whereby we have a repair infrastructure (parts stores, independent mechanics, etc) who have an interest in you keeping and repairing your old car. They have no interest in you buying a new car every time one of your tires goes flat. When it comes to furnaces, we don't have that situation. Any third party who repairs furnaces is also most likely to benefit MORE by selling you a new furnace. Most likely you won't complain or question their recommendation because you have a general awareness that furnaces are important and 10 or 15 years is a long time for anything mechanical to keep working and furnaces are generally a mysterious black box to you so you'd better leave it to the "experts" to tell you what to do.

Reply to
Some Guy

That is all probably true.

In a previous post, I've already roughly calculated that I'd probably save $40, possibly $60 per year if I changed my PSC motor for an ECM motor.

The question that I continue to ask is: What is the "over-the-counter" price of an ECM motor?

I can walk into any hardware or farm supply store and buy a 120v, 1/3 hp PSC motor (for $75 to $150).

Where do go when I want to pick up an ECM motor?

Who sells them "over the counter" ?

Reply to
Some Guy

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What you're doing is arguing that planned obsolescence isn't planned. As I've said, it isn't necessarily a concious descision, but that doesn't make it something benevolent, the end result is equivalent and thus it is you who are playing on words. Planned obsolescence isn't defined as a deliberate scam, although the latter does qualify as a subset of the former.

Planned obsolescence isn't a thing, it's a group of practices all of which have the end result that the lifetime of a product is effectively reduced. There can be many reasons for this, as the wiki article explains.

Reply to
hvacrmedic

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Right save 60$ a year, spend 600 for a motor,, 1000 for the board, get a 1-2 year warranty on a motor that has a record of lasting 6, and if you ruin tv reception on your hack freeze when you watch tv this winter and fry in the summer. it all makes so much sense.

Reply to
ransley

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Like I said, it isn't practical. There will be no payback with that sort of retrofit. And even the greenies who have one installed because their looking at the environmental aspect (less energy), they should take into account that the old motor becomes trash in the landfill, which is also an environmental concern. The only reasonable time to even contemplate such a retrofit would be when the old motor dies, in which case it has to be replaced anyway. For those who simply "want" an ECM, it can certainly be done, but there is no practical advantage in this case, nor is there any benifit to the environment because eventually it will die too, and it contains more than scrap steel and copper in it. Moreover more energy and waste is involved in their manufacture. And to top it all off, it won't last half as long as another PSC motor.

Reply to
hvacrmedic

Again, what is the over-the-counter cost for an ECM motor?

You won't need to spend $1000 for a controller either.

Look. An ECM retrofit probably doesn't make sense now that I've done the math. But don't add to the hyperbole by saying that $1600 is the price of admission for an ECM motor.

Wrong. The old motor would be set aside, and used as a backup when (or if) the ECM motor dies. In fact, if the ECM motor does indeed die after only 3 to 6 to 10 years, then most probably the old motor would go back in and never again be replaced with an ECM motor.

Again it all depends on what the over-the-counter cost is of an ECM motor.

The only price we've heard so far is $600, which if I understand the context was a HVAC contractor repair price, which represents a markup of at least 100%.

Reply to
Some Guy

All of that I agree with. Which is exactly what I've been saying. Manufacturers are simply reacting to what the market needs are.

Now that I'd like to see proof of.

I'd like to see proof that the goal is to get lifespan down to 7 years.

What short lifespan are you referring to? 20 years for a furnace seems like a reasonable compromise in terms of lifespan. And you choose to totally ignore the energy usage that a 45 year old furnace will waste compared to a new one? I'd say that will easily outweigh the energy wasted by recycling it back to the scrap yard. Look at all the environmental programs out there to encourage precisely this kind of action. Utilities and govts are offering rebates for consumers to encourage them to get a new furnace or AC system that is energy efficient. That surely leads to more of the old ones going to the metal scrap yard

And how many customers are going to be willing to pay significantly more for a furnace that will last 45 years, without knowing how improvements, energy sources, convenience features, etc will play out over decades? I'll pay more for something if I think it's going to be worth it and economically makes sense. And for me, 20-25 years is the sweet spot for an HVAC system. I'm not going to shell out much, if anything more for one that is supposed to last 45 years.

Now this is just plain silly. Historically, there haven't been a lot of improvements or changes in 2X4's, bricks, or the basic plumbing system. There has been in HVAC though. Nor can they be replaced with even remotely the ease of an HVAC system. As for things like fixtures, I'd submit that few people today expect any of them to last for 50+ years. People are used to dishwashers, ovens, etc lasting 15 years or so. Even faucets and sinks get changed long before 50 years. I wouldn't want the same style sink or faucet I had 50 years ago. I just replaced my own kitchen sink which was 20 years old for convenience and changing needs.

Not an issue because it isn't happening and isn't going to.

You don't want it to last 5 more years. You keep referring to 45 or

50 years. And without knowing what it costs to manufacture specific items, there is no way for you to know how much more anything costs to build, it's pure speculation.

Welcome to the modern world. Try going down to the dealer and seeing how much a new computer or similar module costs for your car. Or some parts for a refrigerator or stove.

So, they had 95% efficient furnaces 50 years ago? I must have missed that. Plus in many cases, people are using AC systems today as opposed to 1957, aren't they? I suppose any old AC system that is part of the whole picture and that is of similar age is peachy keen too?

There is no constant evolution (at least not in North America).

Reply to
trader4

If you can obtain one wholesale than that would be an advantage for you. If you could install it yourself that would mean even more savings. People do this, and even though they've bypassed me (the contractor) I don't care. More often than not they screw something up and that means I get to charge them even more for the repairs when they finally do call. Some get it right the first time. Good for them. I can't criticize because I've never once taken one of my vehicles to a shop for repairs, I've always managed to repair them myself. If I ever do cause an engine to blow up I suppose that'll make the repair shop owner happy. I don't expect that'll happen though, since I could have just as well walked into an auto shop and filled out an application as into an hvac shop. The only difference between most auto mechanics an me is that they did walk in and fill out that application.

The bottom line is, when in doubt don't. It's those that ignore this advise that tend to make things worse for themselves.

Reply to
hvacrmedic

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All you've said was that you can either buy it yourself, install it yourself, and maybe do it right or maybe do it wrong. Wow.

And if I flip a coin, it will land heads up or tails up.

Why don't you tell us what the wholesale price is of an ECM motor? That would be a useful piece of information to this thread that you can contribute.

This isn't about whether you care or not. This thread isin't about you.

Reply to
Some Guy

I asked my lennox installer what it would cost to retrofit to vsdc, he said about 1600, the electric savings are mimimal, without the low speed option it whats the point, GE vsdc were at one point lasting only 6 or so years, buy a new furnace if you have to have one and get the 10 yr warranty and all the benefits

Reply to
ransley

This thread isn't about anything. It's a figment of your imagination.

Reply to
hvacrmedic

You've admitted that furnace life-spans are getting shorter today vs years ago.

Isin't that proof? Isin't that an example of how they are coming down to match (but never fall below) the average length of home ownership?

If in 5 years we observe that the lifespan of the average new furnace is 7 years, does it matter if we call that a "goal" ?

Any old furnace that's 25+ years old can have it's efficiency raised easily by 10 to 20% simply by turning down the burners. The design goal for those old furnaces was to blast out the heat in those un-insulated homes. They had no concept of constant heat. They had crappy mechanical thermostats and couldn't achieve constant (comfortable) heat output.

Now those homes have added insulation, and if you turn down the burners so the furnace runs longer (but cooler) you've just raised their efficiency and probably increased their lifespan too. Adjust the burner primary air baffles too so that you're not blasting the flames straight through to the flue (ie - increase flame residency time within the heat exchanger to extract more heat from the flames ->

slow the flames down).

And I think it's a crock that your only choice is to replace a

45-year-old furnace with one with an expected lifespan of 20 years. I don't give a damn about how much fuel savings there will be. There is no logical reason why lifespan needs to go down when efficiency goes up.

Back in 1955, what was the inflation-adusted price of a furnace?

Were people paying a fortune back then for furnaces?

Are furnaces today less expensive (in real dollars) compared to 10,

20, 30, 40 years ago?

What good is it if you pay less for a furnace today vs 30 years ago, but you have to buy it twice as often?

You're telling me it's a good thing for the environment to have to buy a furnace every 20 years vs every 40 years? Do you know how many more households there are now, compared to 40 years ago?

We have 95% efficient furnaces today. You're saying it's a bad thing if they last 45 years - because we want people to replace them more often. So I suppose we want them to last only 20 years - because 20 years from now we'll have a 98% efficiency? So for the sake of a few extra percent we want people to buy new furnaces? What the hell kind of logic is that?

Who are you?

A home owner?

Or an HVAC reseller/installer?

If the energy-saving argument is correct, reliable, proven or garanteed, then I don't have to wait for my 45 or 30 or 20 year old furnace to break down. I can choose to replace my furnace at my conveinence. Or not.

Saying that it's a good thing that furnaces last only 20 or 25 years is a crock. If that's what you rely on to make the case to buy a new furnace, then that's a bullshit argument.

Do you know how many old fixtures, tiles, railings, etc, are being torn out of old homes to be installed in new or renovated homes?

Don't confuse style with function. Those old fixtures went out of style 30 years ago, but they still function, and now they're back in style.

Many people do.

I've got a news bulletin for you.

You don't need a furnace full of electronics, sensors and computers to get 95% efficiency. We have 95% efficiency because we have more heat exchangers, essentially more "plumbing" inside furnaces. Closed combustion, intake air pre-heating, etc. Not even electronic ignition is needed (that is another gimic that saves very little energy, and certainly saves no energy when the burners are running).

Of course they knew what it took 50 years ago to build a 95% efficient furnace. There just was no demand for it.

We're not talking about AC. That's another matter.

And if you want to know how "plumbing" can help even more - I'll tell you.

Ductwork should be gated such that in the winter, air can flow around the A-frame instead of being forced through it. And in the summer, air should be ducted so it doesn't have to flow through the furnace heat exchanger.

Take those resistances out of the picture and you've just raised the efficiency of the system. No fancy electronics required.

And you've got no comment about this eh?

| In Japan, they have furnaces with built-in 1 kw electric | generators to provide some electrical co-generation that | can supplement the electricity supply for the house - and | keep the blower running in the case of complete power | outages (like what's happening to thousands in the central | USA right now).

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The biggest crock of shit about furnaces today is that they can't generate their own electricity to run their friggin internal mainframe computer - and their blower motor during a power outage. I bet the electronics in today's furnaces consumes more electricity than the ECM fan motor does.

Reply to
Some Guy

Wrong question.

Ask him what he pays - for motor only.

Reply to
Some Guy

Welcome to my imagination.

Now get lost.

Reply to
Some Guy

What does it matter wholesale price, you pay retail, what a wasted thread this has become

Reply to
ransley

I generally get the opposite impression, both from my experience remodeling, and from people who have built homes.

You get overwhelmed with details and choices that have to be made, often in abstract ways over 2D drawings or worse, over long lists of material choices. The builders want quick, up-front decisions since there's a supply chain delay as the materials are ordered and they want to be able to schedule projects as efficiently as possible without having to stop and wait for stuff to come in.

HVAC is way outside of nearly everyone's area of expertise and the sources for consumer education are few and far between. Among the zillion other choices being made by people building a home, HVAC is the last thing they want to make decisions about and chances are the builder isn't giving them the choice and often has just told the HVAC sub to get whatever is absolutely cheapest, meets new-home code and will last just long enough that the builder can avoid having to warranty it.

I like to think I'm much better informed than most, but HVAC I find deeply frustrating -- there's no good information and when I chat up commercial HVAC guys when I do work in a large data center, they usually laugh at my problems and tell me how bad I'm being raped by the residential contractors

-- which I suspect all along, but I love air conditioning too much, and thanks to Minnesota's winters, I *need* heat too much to complain, so I just pay. And pay.

Reply to
Howard Beale

Without the controller to vary the speed based on optimum air flow under a given circumstance the ECM probably won't save you a dime.

Reply to
gfretwell

ECM motors have a broader and flatter efficiency profile across their load range vs fractional HP PSC motors. While it is true that multi-speed PSC motors are very inefficient at low speeds, PSC motors are not. Then again, many older furnaces have PSC motors with only 1 speed, so replacing them with single-speed ECM motors would make no difference on apparent furnace functionality or comfort, but would make a difference on running cost.

This document is very interesting:

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They go so far as to measure the amount of ADDITIONAL gas needed to heat a home with an ECM motor vs PSC. Why does an ECM furnace use more gas? Because the PSC motor generates more heat, and a furnace with an ECM motor must use slightly more gas to make up for the missing heat source.

In fact, everything else being equal, a furnace with an ECM motor needed to use 14% more natural gas vs a furnace with a PSC motor.

A furnace with an ECM motor being used during the cooling season will clearly result in a cooler house because of less heat being dumped into the house from the motor.

See also:

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"During the space heating test period, the ECM reduced the average furnace electrical consumption from 9.29 kWh/day to 2.38 k Wh/day, a savings of 74 %."

"energy from daily gas consumption rose 14 %, from an average of 213.7 to 243.3 MJ/day."

Cooling Period Results: "Using the ECM saved 48 % of the energy to propel the fan, 4 % of the energy for the compressor, 21 % of the energy for the air conditioner (fan plus compressor), and 14 % of the electricity used by the entire house.

Reply to
Some Guy

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Actually it is known as, "Americans want cheap." When the cost to manufacture a product rises, the logical reaction would be to raise prices to cover those increased costs, so the company can remain viable to provide income for all concerned and to continue to provide a quality product for the consumer. But the "Wal Mart" syndrome has taken us all in. The manufacturer can't raise prices because the customer won't pay. The first to cut costs, mostly by removing jobs from America and using inferior materials, gets the sale. The price and quality are forced down, so we now get people complaining about, "planned obsolescence". But, you probably aren't willing to pay more for real quality, are you?

This is a very simplified example but I hope you all get the point.

Reply to
do_see

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