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Re: A technical question

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more little dribs and drabs of incomplete information?? still trying to milk
this thread??



Re: A technical question
On 11/21/2011 5:55 AM, Steve wrote:
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Well heck, it's kind of interesting to find out how it's done at the
other end of the world. ^_^

TDD

Re: A technical question



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Nope it is a unique design for my home, which I put together.



Re: A technical question
On 11/21/2011 4:05 PM, ramrod@truthonly.com.Sword of Baal wrote:
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Now that I can understand since I hoped to get a really cool two story
house I found nearby where I live now. I could have gotten the house
with one of those Affirmative Action loans that crippled the economy. I
knew better than to get tangled up in that mess because I had no backup.
All it would take was me winding up in the hospital which actually did
happen a few years later. :-(

TDD




Re: A technical question




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Although I do not consider domestic air conditioning my field, I would think
the majority of home air conditioning years ago here were window units, then
non ducted splits systems took over.

In general a home is Australia tend to be single story individual houses
locate on their own block of land.

In the larger city where land prices increased there, apartments replaced
the individual houses mainly towards the centre of the city,  in the larger
cities this is increasing as the land price increase.

This has steadily become more prevalent over the last 40-50 years.

The vast majority of apartments are 3 story as if they go any higher
elevators must be installed.

As you get closer to the centre of the large city, high rise apartment
building are more the norm, than 3 story buildings. This of course is a
generalization.

These individual homes tends to make our cities quite large compared to the
number if inhabitants.







Re: A technical question
On 11/22/2011 9:53 AM, ramrod@truthonly.com.Sword of Baal wrote:
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I have a bit of experience with Australian construction techniques
because in the late 1980's I worked out in the Marshall Islands
and our prefab housing units came from Australia and I had a hand
in assembling them. It was interesting to say the least. ^_^

TDD

Re: A technical question



I have a bit of experience with Australian construction techniques
because in the late 1980's I worked out in the Marshall Islands
and our prefab housing units came from Australia and I had a hand
in assembling them. It was interesting to say the least. ^_^



Prefabs may be used a little in the country, but would be rare.

Mainly homes are built of double brick, brick veneer (Brick outer walls with
plaster board inside), Cement brick, some of timber but the timber places
seemed to be getting less and less common.  There was a period when asbestos
was used in some homes on the outer walls but of course that has now long
gone, although there would still be many homes like that at around.

Some of of the older homes were constructed of stone. When I lived in Sydney
my house was fairly old and made of sandstone blocks.

Multi story apartments are usually cement.

I have seen shots of homes being built in the US using some sort of what
appears to be sheets of glued together timber stuff, this is not used here
anywhere I have seen.



Re: A technical question
On 11/22/2011 12:48 PM, ramrod@truthonly.com.Sword of Baal wrote:

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That's panelized construction, the walls and roof are made of huge
sheets of plywood with 2x4 studs glued between.  Often electrical
wiring, insulation and windows are installed at the factory, too.
I live in one of these.  The only downside is when running wires for
phone, network or extra outlets and lights it is hard to snake them
through the walls or ceiling.

Jon

Re: A technical question


"Jon Elson"  wrote in message

On 11/22/2011 12:48 PM, ramrod@truthonly.com.Sword of Baal wrote:

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As I have said I have never seen that being used in Oz, and I wonder what
the life of it is?

My brick house is around 30 years old and quite sound, but the kitchen
cupboards need replacing as they are made of chipboard and it is starting to
disintegrate.

They tell me that the new chipboard is OK as it has a newer glue, but I will
have to give it quite a bit of thought when I get it replaced if I should
use solid timber. Mind you if the new chipboard last in excess of 30 years
it would outlive me I guess.

Although the wiring was quite OK I have replaced it as I wanted 3 phase
power on and quite a few upgrades in the house, wiring wise.

Being brick veneer home (Brick outside with timber frame walls clad in
plaster board) it is fairly easy to run the wiring down from the ceiling in
the gap between the brick and plaster board.

The water pipes outside the house were plastic and so I have replaced them
with copper. The pipes inside were already copper. In newer houses it seems
the both the hot and cold water pipes inside the homes are sometimes install
in plastic pipe. Maybe I am old fashioned but I prefer copper.The idea of a
plastic pipe bursting in the middle of the night does not make me happy.

In Sydney they replaced all the underground gas pipes with plastic. Quite a
big job as the population is around 4.5 million and it is quite a spread out
city.

It seems to work OK as far as I know, they did the job around 15 years ago.
It seems they just poked the smaller plastic gas pipes through the old metal
ones and run them at higher pressure, so they did not have to dig up half
the streets.




Re: A technical question
On Wed, 23 Nov 2011 01:53:05 +1000, <ramrod@truthonly.com.Sword of
Baal> wrote:

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    I understand the AC units have to be installed upside-down, to
prevent the compressors from spinning backwords ;-)

    Or is that China ????


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Re: A technical question



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Actually our compressor spin a bit slower than yours, as the power supply
here is 50 cycles.



Re: A technical question
On 11/21/2011 5:55 AM, Steve wrote:
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I guess some folks are sooo lonely that they will do anything to attract
our attention.
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Re: A technical question
On 11/21/2011 12:17 AM, ramrod@truthonly.com.Sword of Baal wrote:

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  The fan control is set
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OK, well if you can keep condensing pressure below 200 PSI, that should
be a VERY efficient R22 system.
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This electric reheat is a very inefficient way to do humidity control.
A dedicated dehumidifier would be a much better setup.  Of course, if
they never go on, there's no worry, but if they are used much, it would
probably pay for a dehumidifier in one season.
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Having the system jumping back and forth between heat and cooling will
not be efficient.  This changeover ought to be a seasonal thing, but may
need to be a day/night change, depending on daily temp swings.  Better
insulation and thermal mass is the best way to fight those swings.  It
is a total waste of energy to cool during the day and heat at night.

Jon

Re: A technical question


"Jon Elson"  wrote in message

On 11/21/2011 12:17 AM, ramrod@truthonly.com.Sword of Baal wrote:

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That is why I designed it that way, but on a hot day it would not be below
200 PSI, more likely 240 PSI.

My 6 ton system also had head pressure control and an oversized condenser,
on checking it on a 40 c (104 f) day the head pressure was around 240-250
PSI.

40 c is the highest I have seen it get to here, once in over 9 years.

----------------------

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First of all seeing the plant only will run when there is a fair load, the
cooling will look after the dehumidification in all but a small time in the
year.

The internal load will help.


I did consider putting an heat exchanger in the condenser line  and heating
water and storing it in a 90 gallon tank and using a hot water coil for
reheat, but I could not justify the cost, considering how little the
elements would be on.

It is a balancing act after all, running costs verse install costs.

In England the say if you are going to live in a house for less than 5
years, put in a cheap heating system that is more expensive to run. If you
are going to live there a long time  put a more expensive system in with
cheaper running costs.

--------------


I have 5 major rooms over 2 air conditioning systems. so I would need 5
dehumidifiers. As I have already stated the 6 ton system produces 7.2 litres
per hour (Almost 2 US gallons) of water. IE 172 litres per 24 hours

Dehumidifiers depending on size etc will remove 10 to 20 litres per 24 hours

Somehow I cannot see using dehumidifiers would be practical , sure using
reheat is somewhat of a loss, but as the heaters rarely come on it is fine.
Here the rooms are not turned on 24 hours a day, but only turned on when
required.

Running 5 dehumidifiers 24 hours a day would not be exactly cheap.


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I did not say it would be going between heating a cooling but would over
shoot the set temperature, which would cause a bigger swing in the
conditioned space than wanted.


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It is a personal choice and here with the swings of temperature it is
required.

Possible early morning temperature of 11 c (52 f)  during what you would
call winter (Dry season here) and in the same day and afternoon temperature
of 27 c (80 f) considering there is an internal load in some of the rooms
requires IMHO the unit should be able to determine automatically if heating
or cooling is required..

Today it was 10 AM  in the morning and 24.5 c (76 f) outside and 91% RH
(raining outside) and 30 c (86 f) in the computer room with no cooling
running.

So at that point I turned on a small RAC to bring down the temperature. As
the 2.5 ton system s not operational yet.


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I think you are working on places that get quite cold and do not have big
swings of temperature, not the tropics like where I live where we can get
quite large swings of temperature.

The ceiling is well insulated but not the walls, it would be a big job to
insulate them with something that does not burn,  as I would never have
anything that burns in the house as an insulation.

I have looked at it and it is not really financially practical. Yes it would
be a different story if we had ice and snow here, we do not !!!!.


Sorry, I do not want a 5 ton block of cement in my bedroom for thermal
inertia  :-)




Re: A technical question



On Mon, 7 Nov 2011 07:46:01 +1000, <ramrod@truthonly.com.Sword of
Baal> wrote:

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I am fully aware of that still comes the question what is the best head
pressure to get the most economical amount of heat from the system, that is
all I am asking


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That is what I said.



Re: A technical question
On 11/06/2011 11:12 PM, ramrod@truthonly.com.Sword of Baal wrote:

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To boil it down to the absolute minimum, there is only one case where
RAISING head pressure will increase efficiency, and that is where the
head pressure is so low that the system is circulating primarily gas to
the evaporator.  Once condensing is occurring, then you want to hold the
head pressure right there, at the absolute minimum.

Jon

Re: A technical question
wrote:

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    Correct.  Assuming that point is sufficient to meet load.


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Re: A technical question





  A technical question.

  Using R22  I want to know what is the idea range of head pressure to =
get the maximum heat out if the system with the least power input, IE =
the most efficient head pressure on heating.

  Please no guesses, I do not want to run the system at 400 PSI and chew =
up heaps of power.

  I have ways of controlling the suction pressure thus controlling the =
head pressure within some limits. The condenser (Outdoor coil) is =
somewhat oversized so that again allows me a range of suction pressures =
while the unit is running on heating. Both the heating and cooling modes =
have TX valves for refrigerant control and there is a receiver in the =
system.

  No worries about low temperature IE freezing the outdoor coil as it =
does not get all that cold here.

  As I said the main aim is to get a good heat result with a minimum of =
power usage.

  So what PSI should I aim at from a design point of view on heating and =
economy?

  --------------------------

  Before a first year apprentice starts to tell me what the answer is, I =
have been involved in air conditioning for many decades, so am knowable =
on it. My design experience is mainly on straight cooling systems.

  Yes and perhaps some one had to come be hind you, to get unit =
operating I know because people like me done it more then once! Like =
John dear Dearborn Mi. they paid $50K EE out of Il. for 3-4 weeks of =
work for doing absolutly nothing that took me less then half hour to =
point the problem out and corrected!!

  I designed a 175 ton plant (the biggest I have designed) and started =
up one system that had 9 ton of refrigerant in it. Plus I commissioned a =
few plants that had 3,300 volt motors driving the compressors.

  ---------------------------------------

  Not that I had anything to do with it but I saw one interesting =
reverse cycle plant which had multiple large fan coil units and had 6 x =
Carrier  5H120 compressors on it all coupled together.

  For those not familiar with the Carrier 5H120 compressors they have =
usually something like a  100-125 HP motor driving each of them and are =
an unloading 12 cylinder compressor.

  Nominal tonnage is 120 tons. The system beside having evaporators and =
a condenser had balancing coils to take up any imbalance in the system, =
as any of the fan coils could heat or cool simultaneously if required as =
there were both heating and cooling coils in each fan coil unit.

  =
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=




Re: A technical question



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knowable on it. My design experience is mainly

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Grumpy raved
John dear Dearborn Mi. they paid $50K EE out > of Il. for 3-4 weeks of =
work for doing absolutly nothing that took me less then half hour to =
point the problem out and corrected!!





Seeing I owned my company and was in charge of the installations and =
commissioning they worked.



It is no surprise to see someone like you come in who cannot answer the =
question posed and then rave on, as obviously you have no knowledge of =
any value.






Re: A technical question




  >> Before a first year apprentice starts to tell me what the answer =
is, I have been involved in air conditioning for many decades, so am =
knowable on it. My design experience is mainly

  >> on straight cooling systems.



  Grumpy raved

  > Yes and perhaps some one had to come be hind you, to get unit =
operating I know because people like me done it more then once! Like =
John dear Dearborn Mi. they paid $50K EE out > of Il. for 3-4 weeks of =
work for doing absolutly nothing that took me less then half hour to =
point the problem out and corrected!!





  Seeing I owned my company and was in charge of the installations and =
commissioning they worked.



  It is no surprise to see someone like you come in who cannot answer =
the question posed and then rave on, as obviously you have no knowledge =
of any value.



  When you are so F___ing smart why would you be asking dumb as =
question???


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