Split or Windowtype Aircon?

[OnMyWay]

28 minutes ago, Gary D said:

I have just started to chase tbe wiring in ready the finishing (plastering) and have a question about the split aircon. I've put in spurs for the compressors but I'm unsure about the inside units. Do I need to put in spurs or are they wired from the compressor along beside the pipework. If I need a spur should it be beside the head unit or behind ?

Your power source could be either inside or outside, and power both units.  In any case, they need to have their own circuit breaker. 

If you had the power inside, usually you will have an outlet near the inside unit.  I think in many cases the reason for doing this is because is because there was originally a window type, and it the power outlet was already there, up high near the former hole for the window type.

In my mind, if you have a completely new install, it is much cleaner to have the power outside.  When I had mine installed we put a new circuit breaker in back of the outside unit, using power from a nearby source in the existing wiring.  The power from the circuit breaker is hard wired into the external compressor, and then the inside unit is powered by the wiring that travels with the copper pipes.

Gary, make sure your install is done with good, thick insulation on the piping.  I mentioned on another thread that we have a problem with sweating on the pipes, despite the insulation that was installed.  I am told now that a cheaper, thin (1/4 or 1/2) insulation might only last 2 years and the original install often use the cheap stuff.  It does not cost much to upgrade to 3/4, and I am told inverters should always have 3/4.  Don't know why but I kinda trust the guy's opinion.

I'm getting new 3/4 insulation installed after 3.5 years.  I don't know what the old thickness was yet, but I'm fairly certain it is less than 3/4.  Labor and materials to replace it is about p5000, I think.

I have another exact unit it the back that does not sweat yet, but it has very little use.  Maybe 10% use compared to the front unit.

@bastonjock  Have I got this about right?

Edited November 25, 2019 by OnMyWay

[Gary D]

6 hours ago, OnMyWay said:

Your power source could be either inside or outside, and power both units.  In any case, they need to have their own circuit breaker. 

If you had the power inside, usually you will have an outlet near the inside unit.  I think in many cases the reason for doing this is because is because there was originally a window type, and it the power outlet was already there, up high near the former hole for the window type.

In my mind, if you have a completely new install, it is much cleaner to have the power outside.  When I had mine installed we put a new circuit breaker in back of the outside unit, using power from a nearby source in the existing wiring.  The power from the circuit breaker is hard wired into the external compressor, and then the inside unit is powered by the wiring that travels with the copper pipes.

Gary, make sure your install is done with good, thick insulation on the piping.  I mentioned on another thread that we have a problem with sweating on the pipes, despite the insulation that was installed.  I am told now that a cheaper, thin (1/4 or 1/2) insulation might only last 2 years and the original install often use the cheap stuff.  It does not cost much to upgrade to 3/4, and I am told inverters should always have 3/4.  Don't know why but I kinda trust the guy's opinion.

I'm getting new 3/4 insulation installed after 3.5 years.  I don't know what the old thickness was yet, but I'm fairly certain it is less than 3/4.  Labor and materials to replace it is about p5000, I think.

I have another exact unit it the back that does not sweat yet, but it has very little use.  Maybe 10% use compared to the front unit.

@bastonjock  Have I got this about right?

We will have 3 units and the power will run back to the distribution board, I assume I can use 1 breaker and not 1 for each unit. This is a new house so just trying to put everything in place from the start.

[OnMyWay]

22 minutes ago, Gary D said:

I assume I can use 1 breaker and not 1 for each unit.

Make sure you double check that theory.  I'm no electrician but it seems like this risk of tripping the breaker goes up a lot with all three on the same breaker.

[Gary D]

6 minutes ago, OnMyWay said:

Make sure you double check that theory.  I'm no electrician but it seems like this risk of tripping the breaker goes up a lot with all three on the same breaker.

All three outlets are individually fused and live line swithes. I'm using switched outlets and fused plugs, not hard wiring.

Edited November 25, 2019 by Gary D

[hk blues]

4 hours ago, Gary D said:

We will have 3 units and the power will run back to the distribution board, I assume I can use 1 breaker and not 1 for each unit. This is a new house so just trying to put everything in place from the start.

Both of our units are on their own individual breaker in the distribution board, with nothing else connected.  That was what our installers recommended.  

[Dave Hounddriver]

Question about drainage.

When an air conditioner is left to drip on solid concrete I have known the drippings to eat through and destroy the concrete in just a year.  So split air condiioners all have a drain hose running to somewhere the water can harmlessly disapperar.

I happen to have a toilet vent stack right beside my air conditioner.  It is not exactly a drain, but I cannot see what harm it would be if the condensation from my air conditioning compressor drained into it.  The alternative is a convoluted mess.  What say you all?  The pipe is just a ventilation stack and rainwater often blows into it with no apparent harm done.

[OnMyWay]

25 minutes ago, Dave Hounddriver said:

Question about drainage.

When an air conditioner is left to drip on solid concrete I have known the drippings to eat through and destroy the concrete in just a year.  So split air condiioners all have a drain hose running to somewhere the water can harmlessly disapperar.

I happen to have a toilet vent stack right beside my air conditioner.  It is not exactly a drain, but I cannot see what harm it would be if the condensation from my air conditioning compressor drained into it.  The alternative is a convoluted mess.  What say you all?  The pipe is just a ventilation stack and rainwater often blows into it with no apparent harm done.

You have an open toilet vent stack from a lower floor on your upper floor?  That doesn't sound sweet.

I don't see why a small about of water draining into it would be an issue.

I see some places that just put a bucket under the drip, usually on high mounted window type.  When we were looking a schools, at least two had run drain pipes across the hallway floor to a garden area, then put a Quicrete mound over the pipes.  A wonderful tripping hazard for the kids!  In the U.S., the lawyers would be circling overhead!

[Dave Hounddriver]

30 minutes ago, OnMyWay said:

You have an open toilet vent stack from a lower floor on your upper floor?  That doesn't sound sweet.

Sweet like honey . .  wagon.

But it seems normal to me now.  I have no idea what else they could do to it.  It goes up above the roof level to vent, but only just.  Thus we get some sweet blow back on occasion.

[Tommy T.]

59 minutes ago, Dave Hounddriver said:

Sweet like honey . .  wagon.

But it seems normal to me now.  I have no idea what else they could do to it.  It goes up above the roof level to vent, but only just.  Thus we get some sweet blow back on occasion.

I agree with OMW - it is only water draining into more water (contaminated). It would be different if it came through in torrents but that won't happen in this case... It may even settle the florid aromas a bit? I say go ahead and do it! If you have any problem from that (which I strongly doubt) you can always undo that and try something else...

Edited November 28, 2019 by Tommy T.

[Dave Hounddriver]

1 hour ago, Tommy T. said:

If you have any problem from that (which I strongly doubt) you can always undo that and try something else...

Good thinking.  I can try it and if I don't like it after a couple of months I can shift back to the convoluted system they have there now.