Energy Ratings Of Very Old Aircon Units

[welo]

Is there any way that I run these aircon units (pics) at night and keep a sane electricity bill?

I am thinking about moving into a town house that has those installed. Plan to use them at night (3 bed-rooms).

My goal is to strike a deal with the landlord to share costs on having new ones installed. But if the deal is bad I wonder if I could replace the old units and take them with me if I leave (and the landlord doesn't want to buy them). I plan to stay 3 years but who knows for sure.

I only did a quick check, and the air was still cold, the noise level was moderate (no rattling, etc), and they didn't have a bad smell.

Two of them don't even have a thermostat, but the newer one does. I just spotted the power ratings label on the photo, but forgot to look at it when I was there.

I know those things are bad energy wise, but how bad is 'bad'? I remember seeing (and running them) in a Thai hostel - and now I wonder why they didn't have them replaced because it would probably pay off for them very quickly.

Is it worth to keep the newer one?

I've read several other threads but I would still appreciate opinions and feedback on my specific situation.

thanks!

[Delight]

I,m not sure that new aircon is more efficient than an old one. Given that they are both of the same basic design .Periodic cleaning of air filters is advised. A qualified air con engineer will give more precise advice.

The power is absorbed , in part, by 2 heat exchanger fans (one inside and the other outside the room)

The main consumer of power is the compressor .This is controlled by the thermostat.

When you say no thermostat are you referring to an absence of a room stat .If this is the case then you will have high bills.

Typically the compressor is ON or OFF to satisfy the stat setting.(I,m guessing this bit)

It is the Start –Up that gobbles up the power.

However’ On-Off ‘ is cheaper than ‘On ‘all the time.Probably as per 2 of your rooms.

Latest deigns use a variable speed motor so the motor never stops during an ON cycle. It’s speed just varies to suit demand.

They are marketed as ‘INVERTERS’. This is a reference to the technology which converts an otherwise fixed speed motor into variable speed. They are much higher priced than conventional designs.

I would initially have Room stats fitted . Cheap stats are inconsistent.

You need top performance.

Ideally you need to measure the amps consumed before and after any change. Maybe a simple ammeter can be justified

If you do buy new-store the old ones and re-fit when you leave.

I have high quality(the fan blades are shaped a bit like a propeller-flat blades are rubbish –but cheap) ceiling fans in my condo. They fix the problem at very low running cost.

Edited March 16, 2012 by Delight

[welo]

I've read a view threads here on Thaivisa where members fixed high electricity bills by replacing an old aircon unit.

What I wonder though is whether those units are so ineffective because of their technical design, or just because they are old and/or broken. I guess both.

Meanwhile we decided to move into a different place which luckily doesn't have those very old units. However, two of the units have a design similar to the one on the center-photo above. Brand is Mizu. No idea about age, BTU or Watt - couldn't find any sticker or plate with details.

The landlord had a technician over who cleaned and checked them, and will also replace the 'engine' (compressor?) on one that seemed broken.

I guess I just have to run some tests once we moved in and/or see what the electricity bill will be like.

If anybody could give a basic overview of the different generations of aircon units in Thailand over the past 15 years and how much more effective they have become (roughly), I'd still be interested. But I don't think this is going to happen

cheers

[Naam]

I've read a view threads here on Thaivisa where members fixed high electricity bills by replacing an old aircon unit.

most (not all) of the reports "new AC = electricity bill halved" are exaggerations, some of them are hallucinations

looking at the design of the models you posted my best guess is that the units are at least 12-15 years old. that means replacing them with new more efficient units you might save up to 30% electricity. it's not only the technical design which makes newer units more energy efficient but the materials used for both heat exchangers and different more advanced technology, e.g. rotary instead of piston compressors.

i am bypassing "inverter units" because their efficiency is based exclusively on "how and under what circumstances used".

let's do the maths. replacing the three units will cost approximately 65,000 Baht including installation. assuming a cooling mode of 8 hours for each unit (to me they look like 2 x 12k btu/h and 1 x 18k btu/h) they will draw an estimated total of 5.5kw/h @THB 4 = THB ~192,000 in a 3-year period, id est the assumed 30% savings will pay for the investment (loss of capital investment not considered).

should you however use the units much less, let's say 4 instead of 8 hours you are down ~30,000 Baht.

note, this comparison is based on mere assumptions, your mileage might vary!

[welo]

Thanks naam for going all the way and doing the maths! I appreciate the 'courage' to actually assume/guess specific figures. The 30% is something that I can work with.

I will now wait for my first electric bill

I might also run some measurements on the actual consumption of these units - I have two identical rooms, one equipped with an old unit, the other with a brand new one. Location in relation to the sun is different so I'll have to do consider that (maybe do comparisons in the time between 12:00pm to 6:00am?

Well, I don't even have a power meter yet, so will need to do more reading here on thaivisa...

[electau]

Make sure they all have a thermostat fitted and it is set at 25C. Check the temp with a thermometer.

[canuckoverseas]

Not sure how it works in Thailand..as I'm here in Egypt. But when people rent a place here, many times they buy and install their own AC, then when they move out, they can just sell them to recoup some of the cost. A new premium name branded AC will be much more efficient and quieter than a 10 year old unit, not to mention that it won't have any leaks. New units also come with a warranty. A cheaper option is buy a single AC on your own and install it in the room you'll use the most.

[welo]

@electau

Thanks for this hint. One thermostat actually does not work reliably - I wonder if it might have to do with that it apparently has never been cleaned but painted over during a wall repaint at least once

My first electric bill arrived and while it was not shocking it was higher than expected. I might try to trike a deal with the landlord to have a new one fitted, but will have to wait 2 or 3 months for tactical/psychological reasons.

@canuckoverseas

Thanks for the idea. I dont think that will be a cost-efficient approach though (in Thailand)

[WilliamCave]

I put 2 air cons in a rental unit were i stayed after I sold my other home and was looking for another home. All I did was repair the wall were the holes were and painted when i moved out and the land lord told me I could leave the electrical so it was not a problem they were newA/Cs . If you have the mony buy new ones they are not that expensive and more energy efficient.

[harrry]

You may find there is a thermostat inside behind the grill. I though My old one did not have one but it did. A airconguy replaced it with a remote one for about 1000baht.

[welo]

You may find there is a thermostat inside behind the grill. I though My old one did not have one but it did. A airconguy replaced it with a remote one for about 1000baht.

Mine does have a thermostat connected by cable - and since the brand of the thermostat is different from that of the aircon, I guess the unit itself did not come with one.

Not sure I would invest even 1000 Baht into this old unit But thanks for the hint!

I put 2 air cons in a rental unit were i stayed after I sold my other home and was looking for another home. All I did was repair the wall were the holes were and painted when i moved out and the land lord told me I could leave the electrical so it was not a problem they were newA/Cs

So what did you do with the aircons when you moved out. Did you sell them or could you use them at your new place?