On Dec 22, 9:16*am, hvacrmedic wrote:
On Dec 22, 8:03*am, wrote:





On Dec 21, 11:04*pm, Some Guy wrote:

Tony Hwang wrote:
Just wondering if anyone has replaced their conventional furnace
/ HVAC fan motor (PSC, single phase, etc) with one of the new
ECM motors to realize a reduction in your electricity bill.
Don't even bother. It is DC servorized motor with matching control
logic board. High efficiency furnaces are made to take advantage
of this variable speed motor.

Everything you're saying is true, but it doesn't mean that
fundamentally ECM motors are more efficient regardless in what type of
furnace they're used in.

Even if all I do is use it as a constant-speed replacement for a 50%
efficient PSC motor, it will use less electricity.

The question is - how much, and what is the over-the-counter cost of a
suitable ECM motor (not the HVAC-contractor-installed price).

Also they are not as reliable as ordinary motor.

That is probably true, and along the lines of planned obsolescence
that's designed into modern residential HVAC systems.

I've worked at and with a lot of companies engaged in all kinds of
product design during my career. *But I never heard any discussion of
planned obsolence, which IMO is largely an urban legend. * * There is
a real tradeoff between what it costs to make, how much you can sell
it for, and longevity. *In my experience, that is where the tradeoff
is made.
If you made a product that deliberately lasted 10 years, while it
could last 20, it wouldn't be long before a competitor whose product
did last 20 would start eating your market share because their product
was superior. * That's how free markets work.

The typical funace lasts 20 years. * Given the cost, that seems a
reasonable lifespan. * How many customers would be willing to pay say
30% more for one that lasted another 5 years? *Or 50% more for one
that lasted another 10? * Most people don't even plan to be in their
homes that long today. *Given that the energy situation and technology
is constantly evolving, I don't see a problem with the lifespan or
value proposition presented by today's furnaces.- Hide quoted text -

- Show quoted text -

"Not designed to last 30 years" is logically equivalent to "Designed
to last no more than 30 years". Like I said, it isn't necessarily a
concious desicion, but planned obselesence is precisely what it is.- Hide quoted text -

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The notion of something being planned without it being a conscious
decision defies all logic. My main point is that Some Guy referred
to planned obsolescence designed into today's products. Which to
most people implies there is some specific planning on the part of
manufacturers that is different today to make sure the product only
lasts a given number of years and then fails so they have to buy
another one.

In reality, it's no different today than it ever was. Manufacturer's
are competing in a free economy and reacting to it. That includes
making trade-offs, as has always been done, about how long it makes
sense for a product to last vs how much it costs to build it and how
much people are willing to pay for it. If you want to call that
planned obsolescence, then we agree, but I think it's a poor choice of
words and it's nothing specific to today's products.