# reverse cycle air conditioning heating is more efficient?? - Page 3

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Re: reverse cycle air conditioning heating is more efficient??

Not quite, Dont forget that the sun has put 500W in. You have used 25W
to move 500W, sum total is 525watts needed to produce 500w, which is
not quite 100% efficient, but getting close. Second law of
thermodynamics.

Re: reverse cycle air conditioning heating is more efficient??

You are totally off the track, I don't care about absolute efficiency
or any thermodynamic laws. I *know* the sun is providing most of the
energy, but to me that energy is free and costs me nothing. I am not
arguing anything to do with absolute efficiency at all.

I put in 25W of Electrical energy and I get out 500W of heat energy.
That is 2000% better *relative* to an electric heater, and much better
than a reverse cycle aircon. The exact same conclusion you came to when
you dusted off your textbooks ;-)

Dave :)

Re: reverse cycle air conditioning heating is more efficient??

I can't understand the total stupidity of your argument. How can you include
the energy the sun contributes for free. Free is free. If the sum
contributes 500watts of of free energy and it requires 25watts af energy to
utilise it, you have only expended 25watts of energy. Simple and basic
logic.
If you needed \$2000, and I give you \$1500 for nothing (and with no
expectation of repayment), you have expended a total of \$500. This is a fact
that cannot be disputed.

So, if the sun has given you 500W for free, and you have used 25W to "move"
500W, then the total sum of the energy is 25Watts that you have used. Which
is a bonus and a lot cheaper than you would like us to believe.
No one wants to worry about how much energy is used or saved, they are only
interested in what it saved in dollar terms. This is also fact!

Re: reverse cycle air conditioning heating is more efficient??

That much is clear.

to
fact

Cash is fine then :-)

"move"

Which
only

So simply quote running COST then rather than EFFICIENCY.

MrT.

Re: reverse cycle air conditioning heating is more efficient??

Why?, *relative efficiency* against a benchmark is a perfectly valid
way to represent something, especially for this industry where it is
common practice.

Dave :)

Re: reverse cycle air conditioning heating is more efficient??

*IF* it's stated as such, which it wasn't.

There are many stupid things that are common practice. Doesn't make them
right, just common.

MrT.

Re: reverse cycle air conditioning heating is more efficient??

It doesn't have to be, especially when it's common practice in the
field being discussed. Most of us knew exactly what it was, and it was
cleared up very early on for those who were unsure, but people still
had to be pedantic and harp on about it. Perhaps we should state it in
every single post on the subject just to keep you happy?

It is not stupid or wrong, and it is the accepted terminology, so you
have to live with it I'm afraid :-P

Dave :)

Re: reverse cycle air conditioning heating is more efficient??

I would love to respond, but the beer and the ashes has better of me.
Did you all know that Aus beat UK when it should have been not
possible. ANy way, the original post should be confirmed as relative
rather than absolute. nothing is free...

Re: reverse cycle air conditioning heating is more efficient??

Isnt it related? If something is efficient, then it is cost effective.
If the heat is supplied by nature and the only energy required is to
redirect it, it has to be more efficient than manufacturing the heat first,
hence, cheaper.

Re: reverse cycle air conditioning heating is more efficient??

"Two Bob"  aka John the Schizoid   snipped-for-privacy@iprimus.com.au

** You are ONE  evil,  PARANOID  SCHIZO  NUT  CASE

There is no place for sub human  GARBAGE like you here.

........    Phil

Re: reverse cycle air conditioning heating is more efficient??

Original!

Re: reverse cycle air conditioning heating is more efficient??

Of course it's related, but NOT the same thing.

MrT.

Re: reverse cycle air conditioning heating is more efficient??

That much is clear.

to
fact

Cash is fine then :-)

"move"

Which
only

So simply quote running COST then rather than EFFICIENCY.

MrT.

Re: reverse cycle air conditioning heating is more efficient??

thermodynamic efficiency versus heating efficiency,

Bye.
Jasen

Re: reverse cycle air conditioning heating is more efficient??

David,
Do you ave a link on construction of your dolar heater.
Have been looking at designs on web and want to build one.
I would combine the passive heating with a reverse cycle aircon in
evening..

cheers

George

David L. Jones \$B\$N%a%C%;!<%8(B:

Re: reverse cycle air conditioning heating is more efficient??

Sure do:
http://www.solarsponge.com /
Was published in Renew magazine Issue 94.

Dave :)

Re: reverse cycle air conditioning heating is more efficient??

Dave

Have you though about feeding the inlet from inside the roof space
(near the apex) and using the heat generated by the tiles as well?

Alan

--
Sell your surplus electronic components at
http://ozcomponents.com
We've slightly trimmed the long signature. Click to see the full one.
Re: reverse cycle air conditioning heating is more efficient??

Sure, but I prefer my air fresh!

You would need a very good filter for a start, and that impacts your
airflow rate, possibly even negating any benefit gained from the
pre-heated roof air. The filter would clog up very quickly too, roof
spaces are horrible environments for dust.

Dave :)

Re: reverse cycle air conditioning heating is more efficient??

OK on the dust, that's why I suggested near the apex.  Perhaps a long
metal tube passing through the roof space to the outside air? Just
throwing an idea around.

There was a guy on the "New Inventors" who had a unit that took
(filtered) air out of the roof space to feed down into the house for
heating.  Just thinking that you would increase the heat take up that
way.

Alan
--
Sell your surplus electronic components at
http://ozcomponents.com
We've slightly trimmed the long signature. Click to see the full one.
Re: reverse cycle air conditioning heating is more efficient??

I've visited a house that had the first prototype of a system like that
installed, it didn't seem that impressive.
I did some initial thermal mappings of my roof space to see if such a
system was feasible, it just doesn't get that warm up there in winter.
Perhaps it's my terracotta roof tiles...

Dave :)