Inverters Vs Non Inverters

[Simeonx1]

Ive been talking to a few techs and it seems they think non inverters are better.

I know exactly how they work and all that.

Inverters Cons :

More parts to breaks
More complex to fix
Costs more Expensive parts
Fake star rating
More functions

Pros

Use less energy
Keeps temp more stable
Doesn't have a big start up , cycles less

Non Inverters Pros

Cheaper to buy cheaper to replace parts
Simpler easier to fix
Less complex


Im just repeating what some people have been saying . i dont exactly believe all these things.
What would you guys choose .

[chilliwilly]

Horses for courses

[The Viking]

Back when I were in school I had a teacher that said that it wasn't worth learning about computers as they would never take off on a big scale.

Then when I started in this business the old engineer I learnt from said that digital controls would never take off as they never could compete with old fashioned electro mechanical controls that could be fixed with a screwdriver and a basic electrical tester. (For years I had one of those "pen" type testers with lights on and it was all that was needed for 99% of all control trouble shooting)


Love them or loathe them, inverters are here to stay and the best you can do is to embrace them and learn everything there is about them to stay ahead of the competition.

[mikeref]

Your going to find it difficult to buy a non-inverter a/c soon anyway. Demands on Aus electrical network systems are running high and non inverter a/c's have a high starting current.

[MikeHolm]

Seldom used here in resi units, Japanese yes, American no. Changing very slowly.

[chilliwilly]

Most Mits splits have them, even on recips.

[install monkey]

the old non inverter 3.5 kw split pulls 30amp inertia on start up, a 10kw 1 phase non inverter pulls 90amp inertia
i have replaced my 10yr old r22 3.5kw non inverter and fitted 2x 3.5kw inverter splits at home and they do save money on ur leccy,so for the extra initial outlay,as long as a monkey (doesnt) installs em you should save money

[stefs_cruiser]

Better for what???

It depends what you want to achieve.

If I wanted to design a more efficient air conditioner, I would increase the size of the coils relative to the compressor, but obviously it still needs to look good, and be able to be sold.
So most units are a compromise between what is economical, saleable and passes minimum efficiency requirements.

Inverters are designed to pull a room down, and then tick over at somewhere like 65% capacity.
If the compressor slows down to 65 % effectively you now have that efficient air conditioner with larger coils, and EER will be higher than a fixed speed unit or an inverter running at 100%
This is where the energy saving come from, current MEPS testing in Australia has been adapted to include inverters, but don't do them justice.
Part load testing is classic example of where a unit may have an EER of 3, but at 66% it may be as high as 4.3, yet it must still be sold indicating an EER of 3, and obviously the SRI also reflects this.

[paul_h]

Hi redstormx1.

Anything bigger than 3.5kW cooling capacity, better to get an inverter for sure.
Most manufacturers in the larger conventional fixed speed units still have capacitor, relay and soft start failures.
Of course even with the smaller units, if you want something with a decent build quality, the main brands only offer inverters, so no choice.
No point buying a cheap (off brand) inverter though, like a chigo or chun lan etc, you're right in that regard, if that's what you are buying, stick to fixed speed.

[Simeonx1]

Thanks paul_h , Im not buying anything :P , i built my air con from scratch made the whole thing myself.

Was just woundering because i always hear differant things.

Thats a great point about cheaper inverters . Would be dum to get a cheapie .
And yes a inverter smaller than 3.5kw wouldnt have much point .

[Simeonx1]

Thanks paul_h , Im not buying anything :P , i built my air con from scratch made the whole thing myself.

Was just woundering because i always hear differant things.

Thats a great point about cheaper inverters . Would be dum to get a cheapie .
And yes a inverter smaller than 3.5kw wouldnt have much point .

[Tesla]

Some of us are a little intimidated and frustrated with inverters. They do save energy at reduced loads to a point but use more energy for the work done -- friction losses, compression efficiency, the inverter unit also uses power just like a VSD. Daikin units and some other brands are so complex we cant simply put our gauges on with a few temp and trouble shoot it. With the inverter many other devices become variable instead of fixed.
May be we just need a little more time to understand the newer technologies and how they best work together. I rely on the help from younger guys in the team who have a grasp on it at work.

[Simeonx1]

Yeah i have a daikin Device that i plug into the board to help fault find .

[MikeHolm]

Some of us are a little intimidated and frustrated with inverters. They do save energy at reduced loads to a point but use more energy for the work done -- friction losses, compression efficiency, the inverter unit also uses power just like a VSD. Daikin units and some other brands are so complex we cant simply put our gauges on with a few temp and trouble shoot it. With the inverter many other devices become variable instead of fixed.
May be we just need a little more time to understand the newer technologies and how they best work together. I rely on the help from younger guys in the team who have a grasp on it at work.

Ahhh, Tesla, you are still young......experienced, but younger than me. I think those around 50 years old had a choice to ignore the computer revolution in high school or jump into full bore. I ignored it to my peril but I thought those 10 years younger had it hard wired in.

My response to the inverter debate is to go half way and see if an EEV/evap changes and a single stage pot will help with the lower ambient issues (but this will take a while). Mind you, I am not heating air directly.

[stefs_cruiser]

. Daikin units and some other brands are so complex we cant simply put our gauges on with a few temp and trouble shoot it. With the inverter many other devices become variable instead of fixed.
May be we just need a little more time to understand the newer technologies and how they best work together. I rely on the help from younger guys in the team who have a grasp on it at work.

Most brands will have a way of forcing the unit to run at rated speed.
Taking temps and pressures without doing this is almost pointless.

On a Panasonic for instance, this is achieved by holding the AUTO switch behind the front panel of the wall splits for 5 seconds (it will beep),
This ensures that the compressor will run at 100% and EEV goes to a home position, and basically the unit will now behave like a fixed speed unit.

[Tesla]

I have not got much split experience from previous jobs. I admit I should read more manuals and get a hold of the software and cables to plug in to these units where possible. I see in the commercial field with VSDs Danfoss is preferred by mechanical techs as they are easier to understand where others are not. No doubt there will soon be apps we can download & communicate to the pcb on the unit?

[Simeonx1]

I use a laptop to talk to the air cons i work with and bms systems . Wouldnt want to plug my iphone in it . to complex.
But a fault finding thing might be alright .