Air Conditioner , cheapest way to use it ?

[s8n]

hi guys , we are having a shit summer in Australia and was wondering what is the cheaper way to use our Air Conditioners.


ok , we usually let the temp get horrible indoors and then turn on the Air Con. It needs to be on 22-23 degrees Celsius and it pumps out air at high speed.

or , turn the Air Con on about 2 hours before it gets hot indoors and leave it on 25-26 degrees Celsius. The Air Con pumps out air on medium to low



chat soon

[Stark]

AC units don't really take much power to run, at least the personal units I am used to.

[ScOtacon]

Air conditioners are inherently very inefficient machines, but operate most efficiently when on high speed. Letting the room get warmer and then turning it on high will be the most efficient way to use it. The higher the compressor speed and the warmer the air entering the air conditioner is, the more theoretical efficiency you will achieve.

If you want to maintain a relatively constant temperature in the room though, you should turn it on a lower setting. It will operate at a less efficient rate, but it wont turn on and off constantly, which can lead to premature part failure.

[CRTGAMER]

Just turn it on before it gets too hot inside. If you wait until the room is very hot that AC is going to work overtime and not last. Definitely keep up on dusting out the coils outside and the filter inside.

[emwearz]

I have 4 1KW units on a 4KW inverter. Mine run at 25c from about 9am (when it starts to heat up), I just leave them on medium all day unless more people are in a room, in which I have them on high. If I can cope with it I drop them to low at around 3:30pm-3:45pm until. Only rooms people use during the day have them running.

The big thing is it costs more power to cool a hot room quickly then it does it have a room stay cool from the morning.

I do this pretty much all summer and the 3 month bill period goes up like $80 compared to the last one, that's like $26 a month. Less than a dollar a day to be comfortable in your home, too easy.

Something to remember is that power companies charge you depending on your peak times, some companies peak is usually around 4-8PM on weekdays. A company like Origin Energy charge you 30c c/kWh during that time, they then shoulder off for 2 hours either side at 22c c/kWh then off peak is 17c c/kWh.

So if you run it on high during off peak, get to about 3:55PM and drop it down to medium or auto (which never tends to run near high) for that 4-8PM time frame.

If you work around the Peak and Off Peak Tariff's you can manage how much you are billed easier, just by being aware.

[s8n]

oh shit , i forgot to mention they ( 2 ) are Inverters.......... don't know if that makes a difference

[emwearz]

Same principles apply regardless.

[flojocabron]

If the AC is over two years old, have someone open it up and give it a maintenance. Clean out the coils with a mild acid/cleaning solution and clean out any accumulated dust.

Cleaning out the unit maintains the life of it. I say two years because the AC should be okay for that long. Newer units tend to work okay but after a few years, the condenser coils or refrigerant leaking may affect how well the ac works for the next year.

Also a trained tech (or savvy DIYer)can spot any weak metal parts or leaks in the coils or metal condensers. Which may need some slight soldering or patching to prevent the coolant from escaping.

This is why older AC's dont cool rooms anymore, all the cooolant is gone.

Machines over 5 years old can still be repaired, usually maintaned every year or other year. But older AC like this are sometime too old and its time to buy a new one.

Here in Mexicali where I live, AC's are definitely needed and people constantly repair their old units, or import broken or busted AC's where they then fix them or resell them.

Many people in the US change out their AC units every year and many of them end up down here in mexico, where some slight repairs make them just as good as new.

[Jagosaurus]

Holy smokes... 30 Australian cents per kw? That's robbery ! Comes out to roughly $0.22 US. Here in Houston electricity is deregulated, meaning one parent company provides the infrastructure & others resell it. This creates a competitive market where you can pick your energy "provider." Mine runs about 10 to 11 cents/kw on average (less if there's a promo for switching providers), so 13-14 cents Australia.

What we deal with here in Houston is humidity. We're called the Bayou City for a reason. It's a freaking swamp. It gets 100+ degrees Fahrenheit, and the humidity can reach 100% on the scale.

Even if it is 77 F outside, it might be 80% humidity so we have to turn on AC units on 74 or so, to cut on the machine and "suck" out the humidity. We typically have central air ran throughout the house versus dedicated room/window units.

Also, if an AC is oversized here, it will get the room down to set temperature too quick, not allowing the humidity to be removed, creating a damp and cold room. This is what happens in a lot people's sheds/garages when they decide to put a big unit in it.

On the flip side, too small of a unit will be overworked.

For comparison, my house is ~2,400 Sq ft and I have a 3.5 ton, 42,000 BTU, 16 SEER centralized unit. My garage isn't included in that count as it isn't HVAC controlled.

Having the correct sized unit for your climate and Sq ft is very important. When you build a new house here, that is actually part of the inspection process. AC is something we spend $10,000+ on when building a new home here. Crazy, but it's a necessity. It's just baked into the construction costs/loans. Repairs or possible replacement can be a big factor when looking at buying homes with units nearing 10 years old. I know it factored into my decision to build new.

Then of course preventative maintenance. My unit is 2.5 years old & I'll have maintenance done soon before summer hits here. I have 2 return air filters I change regularly myself. There is also a condensation drainage pipe in my attic central unit I ensure is clear and pour bleach down occasionally to clean out.

I have a pre-programmed thermostat based on schedule. House temp goes up to 80 F when I'm working and is 76 F when I get home. I can adjust manually from there if needed. That automation based on my schedule is baked in savings.

[Jagosaurus]

Also worth noting, insulation is really important. I know folks who have added spray in insulation to their attic and nearly cut their AC cost in half.

When I built my house, I went with R38 level insulation & radiant barrier in the attic. Seems to help!