Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

"z" wrote in message
oups.com...
Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

positive pressure usually

Everyone I've ever seen the blower is before the heat exchanger, which
only makes sense, as you wouldn't want to put a motor in a hot area if
you can help it.

"z" wrote in message
oups.com...
Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

The air path in the hot air furnances that I've had is: cold/return
air--filter--blower--heat exchanger--plenum--humidifier--supply pipes.

So, if anything, there is a slight positive pressure in the area around the
heat exchanger relative to room air.

TKM

yes the blower is before the heat exchanger

also so that the heat exchanger is under positive pressure...

if the heat exchanger cracks the distribution air will be forced into
the combustion air and not the other way rond which would be much more
dangerous...

http://www.bacharach-training.com/Tips/Tips.htm

Mark

On 20 Dec 2005 12:50:32 -0800, "z" wrote:

Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

Mine's a big-ass squirrel-cage that forces air TO the
heat-exchanger, presumably also because on the other
side all the parts would have to stand up to more heat.

On 20 Dec 2005 12:50:32 -0800, "z" wrote:

Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

I don't think that is a dumb question, and the answers were
interesting.

And remember, there is no such thing as a dumb question. Only a dumb
person.

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me know if you have posted also.

"mm" wrote in message

And remember, there is no such thing as a dumb question. Only a dumb
person.

What if they start asking questions though?

Edwin Pawlowski wrote:

"mm" wrote in message

And remember, there is no such thing as a dumb question. Only a dumb
person.


What if they start asking questions though?

Case rested

hvacrmedic

Mark wrote:
yes the blower is before the heat exchanger

also so that the heat exchanger is under positive pressure...

if the heat exchanger cracks the distribution air will be forced into
the combustion air and not the other way rond which would be much more
dangerous...

http://www.bacharach-training.com/Tips/Tips.htm

Mark

Yeah, that was kind of my hunch.
There was a puddle of oil in the bottom under the burner, and I was
thinking the air leaking from the exchanger maybe blew it away from the
burner.

Edwin Pawlowski wrote:
"mm" wrote in message

And remember, there is no such thing as a dumb question. Only a dumb
person.


What if they start asking questions though?


Then you have "dumb person questions," which is
really what is commonly meant by a "dumb question."

On Wed, 21 Dec 2005 03:21:56 GMT, "Edwin Pawlowski"
wrote:


"mm" wrote in message

And remember, there is no such thing as a dumb question. Only a dumb
person.

What if they start asking questions though?

Darn.

LOL



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On Tue, 20 Dec 2005 20:57:07 -0500, mm
wrote:

On 20 Dec 2005 12:50:32 -0800, "z" wrote:

Is the fan before or after the heat exchanger? I.e. is the heat
exchanger under positive or negative pressure?
Thanks,
Pondering

I don't think that is a dumb question, and the answers were
interesting.

And remember, there is no such thing as a dumb question. Only a dumb
person.

FTR, I left off the smiley but I was kidding.

I had a girlfriend for a while, and one of her big complaints was that
I asked questions, the answers to which were obvious.

I hadn't noticed this, but I spent years paying attention, and it was
true.

But it was still a good idea. I usually got more information in
return than I already knew.
Sometimes what I thought was the answer wasn't.
And people don't like it when you start off with a really hard
question. But if I ask an easy question first, and he answers it and
I appreciate the answer and show it, we're both happy. If I have
another question, he'll make a bigger effort to answer it.

This happens with me especially if I'm just watching someone working
in public, who has no responsibility to answer my questions at all.


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