Inverter V normal aircon unit running cost

andrew4232



Joined: 04/07/2009
Posts: 1543

Message Posted:
15/07/2010 19:57

i know am sure this question as been asked on threads before but am having a senior moment could anyone in plain english give me an idea in real cash terms as to how much per hour the two types would cost to run based on the the following



both 18000 btu or inverter eq set at a temp of say 24

lecky at base rate of 30kr

ie: 1 hours running would cost ?



sorry if this is a repete as am looking to buy a unit and trying to work out the best option for me



many thanks

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 00:11

Hi Andrew

I am going through the same exercise at the moment. I asked the Fujitsu (not Fujicool) importer in Lefkosa, the same question last July when I was asking for quotes & was given this answer:-



"Lets say C Class units are the regular heat pump on-off models we know. A Class models are %25 more efficient(less electricity usage) and the inverter models are %50 more effficient than C Class".

You can buy A class non-inverter as well as Inverter units".



Now in 2010, our current unit is on it's last legs & not worth repair IMO & I am looking to replace with something far more electric bill friendly.



Also try this website from the Australian Government for more info. as well. It makes interesting reading & also gives the impression that we are buying A/C units in the TRNC that are too large as well, based on the sq meterage only of the room. This makes the outlay dearer & it also seems that an oversized A/C unit doesn't deal with humidity as well as the correct sized unit.

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 00:14

ctd.

Unfortunately because wall/roof Insulation in the TRNC is very poor, then it is difficult to know what size you really need here?

For this reason I am going to ensure that any supplier for a good quality unit at a higher price, comes out to check the room first. I shall ensure that he knows his stuff before I order.

IMO it is likely that retailers selling cheaper & poor efficiency, non inverters units will try to sell larger units than you perhaps need?



http://www.energyrating.gov.au/acl.html



http://www.energyrating.gov.au/acuse.html



http://www.energyrating.gov.au/appsearch/air_srch.asp



The last link rates all the units currently imported into Australia & also those that are no longer sold. The list is vast when the old items are included.

This shows the value of the inverter unit, but also shows that some non-inverters with good low energy ratings.

It shows the usage in watts for each unit versus kilowatt output (performance), which can be equated back to btu.

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 00:16

ctd.

It shows the usage in watts for each unit versus kilowatt output (performance), which can be equated back to btu. You can see the btu output, generally incorporated in the manufacturer number. eg 9, 12, 14, 18 etc.



Hope this helps a bit. I will not be rushing out to buy this time & hope our current A/C makes it through this summer.



Partner of he "of the no longer moustache".

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
16/07/2010 10:51

andrew4232,



If I could ask you a few questions I could give you my best advice.



1. Do you live here "full time" or is yours a holiday home?

2. Will you use your aircon for heating in the winter?



As to payback costs, Wiki says:

"The higher initial expense is balanced by lower energy bills. In a typical setting the pay-back time is about two years (depending upon the usage).

http://en.wikipedia.org/wiki/Inverter_%28air_conditioning%29



Scruff,



Reference oversizing of equipment, there may be a temptation to go down a size rather than up a size. i.e. fit a 9000Btu unit where the heat load calculation indicates say 10500Btu, rather than fit a 12000Btu unit.

Inverters come into there own when they run under part load and the compressor can slow down. This is because the motor is more efficient at part loads rather than full load. In the xample above, a 9000Btu unit may never run at part load and zero energy savings would be made, whereas a 12000Btu unit would largely run at

zappa


Joined: 29/04/2009
Posts: 8

Message Posted:
16/07/2010 10:54

Hello

Just to give you an idea, because off a little baby in March, we had the inverter air cons running during the day 2 x 18000 btu and at night 1 x 12000 btu. They were heating the room to 22. The bill went up 100 tl.

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
16/07/2010 10:56

part load most of the time and energy savings would then be made.



Wiki says:

"Inverter-based air conditioners have their strengths in environments where a partial load is common, as they are significantly more efficient than conventional air conditioners in those situations. For conventional households where each outdoor unit is connected to a single dedicated indoor unit, inverters are the preferred option, as partial loading is the common mode there. The higher initial expense is balanced by lower energy bills."

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 14:52

Vaughan, I'm no expert, however I'm am basing my views on the Info. of the Australian Government website re. the output required per square metre of space to be cooled/heated per this link which gives indications for both bedrooms & living rooms. http://www.energyrating.gov.au/acl.html

Obviously this may be too simplistic, however nowhere can I find a clear indication of exactly how the heat load calculation is carried out, to assess the size of unit required.

Why is this so difficult to establish & if it isn't why can I not find anything in print on well known brand manufacturers websites. Is this really a rocket science issue?

I am no way trying to go too low with size, but on the other hand I would like to ensure that the unit which I eventually purchase is the correct size. The significantly differing costs of, in particular inverter units, make this essential IMO.

Obviously this is far less important when buying a cheap non-inverter unit, available here

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 14:53

ctd.

in the TRNC & to be fitted in a holiday home & used for just a few weeks every year for cooling only.

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
16/07/2010 15:30

scruff,



The figures given on the website of between 80 and 125W/m2 are Australian a/c industry norms. They are a quick and easy way of making a calculation, but they are based on many things:

Construction of walls (U Values), area of glazing (double/single?), aspect of walls, number of external walls, flat roof above?, anticipated ambient temperatures. You could work these figures out (and I have!) but by and large they always work out to something you can put a W/m2 "factor" to.



http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/air-conditioners/sizing-worksheet/index.htm



More to the point, if you were to take a bedroom 3mx3m as an example, whether you used 80W/m2 (720W) or 125W/m2 (1125W) you will find that in the case of 720W = 2262Btu or 1125W = 3537Btu. As the smallest a/c unit commonly in use is 9000Btu, that is what you would end up fitting.

Once you get to larger rooms where you would start to exceed 9000Btu, then calculations become more relevant.

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 16:05

Thanks very much for that Vaughan. This is just what I needed to know. When doing a simple area calculation of the bedroom in question, it seemed that a 9000btu unit was MORE than adequate.

Obviously I was aware that the insulation of the room was very important. Rooms here heat up within 48 hrs of an increase in the outside temperature. Presumably the direction that the windows face, whether there are shutters fitted which are kept closed & also the direction that the condenser unit faces, which I understand, also plays a part as well, are also important.

Actually it seems that a few well known manufacturers now make 7000btu models. Maybe this is because insulation is becoming ever better in countries like Australia & Southern USA?

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
16/07/2010 16:14

Also thanks for the link. I had found the website, but wasn't able to access the worksheet.



I am determined, this time, to buy the best possible A/C unit I can find here in North Cyprus in terms of performance versus initial unit cost. Electricity is only going to get dearer here & our bedroom unit is heavily used through the summer. Our existing unit uses approx 13/14 units a night at present, but that does include the usage for the fridge freezer (unlikely to be Class A) & a computer as well, which are running all night. I may consider turning off the water machine which is working in cooling mode all night.

zappa


Joined: 29/04/2009
Posts: 8

Message Posted:
16/07/2010 17:49

At the moment bloomberg has very good promotions on inverter air con, we have fijutsu general and are happy with them.

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
19/07/2010 10:17

Hi scruff,



There are a few companies that make a 7000Btu machine but, depending where you are in the world, they are only a few pounds cheaper than a 9000Btu unit, with the cost of installation remaining the same. However, you should bear in mind the fact that inverters are most economic at part load. If you get a unit which is "too small", it may not spend much time at part load and end up costing almost as much to run as a non-inverter system.

I would definately recommend an inverter unit to you and I can, if you wish, supply and fit either Blomberg or Fujicool, both of which are very competitively priced. You could go mad and go for Japanese kit, like Daikin, Mitsubishi Electric, etc., but your payback time would only take longer.

If you wish, we can continue this off-board at:

vaughan@sunnycyprus.net

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
19/07/2010 13:41

on the other hand, vaughan, i have seen several Mitsubishi air cons installed 20 years ago. good quality has its advantages.

again an air condi discussion.... all about a small 9000btu air con. ok, but in general: only if you have a proper insulation, you can think about proper cooling / heating eg your living room.

msg 1 suggests a "lecky at base rate of 30krs". due to VAT and others, completely unrealistic. minimum is 0,38 krs. fridge, kettle, waterpump, TV, lights.... these are the "base rate" consumptioners. with an aircon you are not in the base tarif any more, you are at 45krs. with two aircons you easily hit the 50 or 60krs .... plus pool pump, second fridge, freezer, water cooler.. the lot. Srcuff is using 13/14 units per night.... this isnt base tarif! base tarif is approx 8,5 units per day!

Reduce your energy needs... and you most probably could cool your whole house with one or two 9000 btu aircon.

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
19/07/2010 13:57

I have also seen Daikin and Mitsubishi Electric a/c systems in the UK which go back to the 80's and 90's. However, they are not usually inverter driven and many use gasses which have been phased out under the Montreal Protocol.

I think I am saying that there can come a time that, like an old car, an a/c system can be said to have outlived its useful life and should be replaced, sometimes before it dies, by a more energy efficient, eco-friendly system.



You are correct in pointing out that base rate electricity applies to things like lighting, cooking, hot water, etc., things which we all use every day. Once we get to our "optional" items like swimming pools, a/c, etc., we need to make sure that we are as cost effective as poss with these higher tariff consumers.

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
19/07/2010 15:41

Vaughan,

the old question: replace something old or not.... the most common example is old car versus new car.....

buts usually not the case here. the aircons are 1-5 years old and.... hit the electric bills.

and thats to 80% not because they are inverterdriven or not, this is because they need to cool against these massive heat losses of the non insulated houses.

You know, Vaughan, iam a suporter of inverter driven a/c . But, these again and again upcoming discussions fizzle out....somehow.

a Energy A+ fridge during its lifetime saves so much energy that the whole fridge is "for free". a solar driven pool pump pays the initial cost 3 - 4 times. all very obvious, but neither A+ fridges nor solar pool pumping nor inverter driven a/c sell very well. if home buyers would only have spent the same "energy and time" in planning their home properly as they spent now in finding a new a/c, we wouldnt have these endless discussions....

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
19/07/2010 16:02

Thanks for all your comments. I would agree that the originator of this thread quoting 30 kurus per unit in message 1 is just plain wrong. Unless he is very frugal with his electric usage, once he gets an A/C unit, he's going to get into the 35 at least & maybe the 38 or 50 kurus band. Then there are the monthly standing charge to add on + KDV.

Our unit prices over the year, using the current tariff & taking into account the extras I have mentioned were between 38 kurus in April 2010, 40.4 kurus in January 2010 & 39 kurus in June 2010. Last August the unit price was 39.8 kurus.

Vaughan, I have been unable to find any information whatsoever about the efficiency of Fujicool inverter units & haven't even managed to find a website for them. They are not included in the Aussie Gov. list, amongst the thousands & thousands of different units listed, including those sold in the past in Australia & NZ.

This leaves me with no info. to consider before making a decision to buy this brand?

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
19/07/2010 16:13

ctd.

Obviously I am not considering buying a 7000 btu unit or probably even 9000 btu, but probably 12,000 btu because I know the insulation in houses here, including my own is abysmal. All I'm trying to do is get the facts before I make a final decision.

There's also no point in going for a brand or model that isn't currenty available in the TRNC. However, there are importers here of the 2 of the leading manufacturers, Fujitsu & Toshiba, albeit at a price.

As I have said before, if you live here 24/7 & 365 days, it is more important to get the most cost effective option despite a higher initial price. I am not at this time considering buying a unit to deal with either cooling or heating our living room, simply because it is too open plan & comprises kitchen, small living area, large hallway & very open stairwell.

The bedroom is shut off though & is an essential, especially for cooling over 3 to 4.5 months.

The information I have received so far has been very useful.

ctd.

scruff


Joined: 15/07/2008
Posts: 1070

Message Posted:
19/07/2010 16:16

ctd.

Hopefully, it has been so for others as well.

Kibsolar. My 2 A/C units are now 8 yrs old, purchased in May 2002 & presumably well out of date now in terms of efficiency. I shall be replacing only the main bedroom unit. The spare bedroom unit is not used often, so the running cost is minimal.

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
19/07/2010 16:46

scruff. my thoughts have been " general remarks".

dont worry, 2002--- 2010, nothing changed a lot. the heat pump technology is old and sophisticated, no wizards around. the cheap stuff became cheaper ( high electricity costs), the good stuff is now a little more expensive as you can save more...

TRNCVaughan


Joined: 27/04/2008
Posts: 4578

Message Posted:
20/07/2010 10:19

scruff,



Fujicool are a "generic" brand of a/c made by a Chinese OEM (Original Equipment Manufacturer). They are "badged" units, that is to say the buyer names the unit and they are manufactured as such, in this case Fujicool. This is quite common practice and the only thing I have cause to disapprove of is when they are badged as something they are not, i.e. they use a household name in order to lend some credability or covenance where there is none.

Blomberg is a similar piece of OEM equpment but I have seen the documentation on both of these and they are "A" rated inverter-driven units.