Reverse Cycle Air Conditioning

[Kompulsa]

Hello.

A quick question. Do reverse cycle air conditioners actually reverse the compressor or is it just a valve that they use to divert the refrigerant?

[chillerman2006]

Hi Kompulsa

I will jump on this one mate, as most engineers would not know this !

The compressor I think

R's chillerman

[r.bartlett]

Hi Kompulsa

I will jump on this one mate, as most engineers would not know this !

The compressor I think

R's chillerman

Sounds reasonable. I have just fitted a flexiflow water pump which shows when you connect the pump(bl-bl & r-r) it runs clockwise but if you reverse the wires (bl-r & r-bl) it will run anti-clockwise

cleaver stuff these wiggly amps

[mikeref]

Hello.

A quick question. Do reverse cycle air conditioners actually reverse the compressor or is it just a valve that they use to divert the refrigerant? My answer is: the valve changes the direction of refrigerant flow :eek:. One way street here, no reversing the compressor. BTW, love the Jamaican Rum!!:)

[chillerman2006]

My answer is: the valve changes the direction of refrigerant flow :eek:. One way street here, no reversing the compressor. BTW, love the Jamaican Rum!!:)

Hi Mike

are you sure about that mate or is it the ''Rum'' talking :eek:

may be you could explain for the 'original poster' 'RB' & myself how this all works

if you could start with the vapour compression cycle in cooling mode

& then break us in slowly to reverse cycle, would be most useful :rolleyes:

R's chillerman

[mikeref]

Hi Mike

are you sure about that mate or is it the ''Rum'' talking :eek:

may be you could explain for the 'original poster' 'RB' & myself how this all works

if you could start with the vapour compression cycle in cooling mode

& then break us in slowly to reverse cycle, would be most useful :rolleyes:

R's chillermanOh... Would be happy to do so, but i seem to remember a previous engagement with my bottle of spirits and the "sandman" tonight. Maybe some other time then?

[MikeHolm]

One direction CM, reversing valve changes the flow direction.....Appletons is my fav rum....yum

[TRASH101]

If the flow of time reversed then that would be a "real" reverse cycle!!!!

Although a valve might also do the trick

[mikeref]

So it seems we have some "For" and "against" here. Think i'll go with Trash101 at this time. Seems reasonable in my current state of mind thankyou..

[chillerman2006]

:off topic:
Oh... Would be happy to do so, but i seem to remember a previous engagement with my bottle of spirits and the "sandman" tonight. Maybe some other time then?
Yeah, enjoy your zzz's mate

.Appletons is my fav rum....yum Mike, check out the picture, will save the rest of this, just in case you get round to visiting us in the uk !

If the flow of time reversed then that would be a "real" reverse cycle!!!!


Hi Trash

if ever you discover that one mate, keep me in mind for a beta copy ;)

R's chillerman :off topic:

[chillerman2006]

Hello.

A quick question. Do reverse cycle air conditioners actually reverse the compressor or is it just a valve that they use to divert the refrigerant?

Hi Kompulsa

See attached picture

R's chillerman

[r.bartlett]

My answer is: the valve changes the direction of refrigerant flow :eek:. One way street here, no reversing the compressor. BTW, love the Jamaican Rum!!:)

I can assure you my water pump specifically states you swap the wires to change the direction. This is very confusing....

[taz24]

.

There is no refrigeration compressor that I know of that runs in reverse.

Think about it?

A recipricating piston compressor does not know which way it runs because the rotation is
converted into up and down motion. It is the valves that direct the gas.

A scroll can only run one way
A screw can only run one way
A centriff also.

I'm not sure of a rotor????

So the compressor always runs and always sucks through the suction
and out through the discharge.

It is the valve that moves to create the flow to move in the oposit direction.

All the best

taz

.

[Kompulsa]

Thank you. I believe that the compressor doesn't reverse either. My Toshiba datasheet says that it is for the Heating and Cooling type of air conditioner and nearer to the bottom it says "do not try to reverse compressor".

[chillerman2006]

Hi RB

I remember a screw compressor wired red, blue, yellow (by another I hasten to add)

That ran backwards too, but for some strange reason needed replacing

I decided to go for red, yellow, blue and thats was ok :confused:

R's chillerman

[MikeHolm]

So it seems we have some "For" and "against" here. Think i'll go with Trash101 at this time. Seems reasonable in my current state of mind thankyou..

Current state meaning RUM?:D

[taz24]

I can assure you my water pump specifically states you swap the wires to change the direction. This is very confusing....

Water pump?

It will most likely use a small vane so rotation could be in both directions.

But think of how most water pumps work?
They draw water in from one side and the rotor, turbo, centrif, vane or waterever
they are called, then spits the water out through the other hole. So even a normal
water pump would struggle with direction.

If it is a peristaltic type pump they run either direction.

All the best

taz

.

[MikeHolm]

Hi Kompulsa

See attached picture, looks I may be wrong !

R's chillerman\

I should have made a wager on in for the bottle of rum.....

[MikeHolm]

"Circulator" type or any other type of pump that takes liquid from the suction at the centre and discharges from a spot on the edge of the impeller will not work well backwards (Grundfos, Wilo, any inline pump). The impeller and the input output geometry must be symmetrical (or nearly so) and scrolls for sure are not symmetrical.

Positive displacement such as vane or lobe pumps can do it.

[taz24]

Hi RB

I remember a screw compressor wired red, blue, yellow (by another I hasten to add)

That ran backwards too, but for some strange reason needed replacing

I decided to go for red, yellow, blue and thats was ok :confused:

R's chillerman

I remember a Bitzer semi hermetic srew that had a faulty discharge
one way valve and when it turned off the gas just reversed the
the screws and it ran backwards.

The only problem was the main bearing is also a thrust bearing and
they are designed for the load in one direction only. When the thing
ran in reverse it put loads on the bearing in the wrong direction and
it siezed up.....

All the best

taz

.

[chillerman2006]

I remember a Bitzer semi hermetic srew that had a faulty discharge
one way valve and when it turned off the gas just reversed the
the screws and it ran backwards.

The only problem was the main bearing is also a thrust bearing and
they are designed for the load in one direction only. When the thing
ran in reverse it put loads on the bearing in the wrong direction and
it siezed up.....

All the best

taz

.

Hi Taz

yeah easy to spot mate, in reverse by the sound they make

the one I refer to (also a bitzer) had only run a short period of time

but by time I got there & rewired it was too late

the compressor went down the following day

R's chillerman

[r.bartlett]

Water pump?

It will most likely use a small vane so rotation could be in both directions.

But think of how most water pumps work?
They draw water in from one side and the rotor, turbo, centrif, vane or waterever
they are called, then spits the water out through the other hole. So even a normal
water pump would struggle with direction.

If it is a peristaltic type pump they run either direction.

All the best

taz

.

They are not called heat PUMPS for nothing I can tell you..

[r.bartlett]

I stand corrected..

[taz24]

They are not called heat PUMPS for nothing I can tell you..

Cheeky.

I'll tell on you young mister Bartlett if you don't stop picking on me :)
.

All ther best

taz

.

[Kompulsa]

I'm pretty sure that mine is at least the type that does not reverse but can be used with reverse cycle systems. i wonder if mine is specifically made to handle cycle reversal or if they just use standard compressors. :D

[simon@parker]

wot about the little guy inside the unit that turns everything around so it works backwards ;)

[install monkey]

si is that the same lil guy in the atm machines and the photo booth's haha

[simon@parker]

si is that the same lil guy in the atm machines and the photo booth's haha


yeah theres loads of them :) bet they get paid well :)

[stufus]

You can hire them wee lads ,
Try Access All Areas ,or Rent a runt ,
Very handy for those tight shafts or passing the time on your breaks by seeing who can throw him the furthest .
Cheers
Stu

[texas64]

Just another name for "heat pump".

http://www.youtube.com/watch?v=TqlYsXnICXw