Page 1 of 1

Aircon question

PostPosted: Thu May 16, 2019 12:17 pm
by 2Sheds
As an Aircon novice, I'm probably asking the obvious but here goes!

Why do Aircons have seperate Heat and Cool modes? when there is an AUTO mode which seems more logical.

In testing, if I set it to say 26 deg in HEAT mode it noticeably heats the room.
The room seems very different when setting it to 26 deg in COOL mode (usually overnight).

Haven't tried it but shouldn't room thermometer show 26 deg in either mode?

Grateful for any simple explanation!

Re: Aircon question

PostPosted: Thu May 16, 2019 12:33 pm
by marcliff
Possibly because when it's cold you want to heat it up and when it's hot you want to cool it down?
Dragging it up from 11C up to 26C would require heating, dragging it down from 34C to 26C would require cooling.
I think you'll find the auto mode only refers to the speed of the fan.

Re: Aircon question

PostPosted: Thu May 16, 2019 1:15 pm
by 2Sheds
Thanks.

The reason for my question was because I'm just trying out a new Aircon, so in these current ambient temps.
26 deg in HEAT mode noticeably heats the room up. Seems a lot warmer than the 26 deg 'cool' which we have set overnight.

The AUTO mode I'm referring to definitely refers to auto heat/cool (not just the fan).

Thinking about it. Maybe it's just the initial sensation of warmth when having it on Heat mode. Perhaps if left on Heat over a longer period of time it would stabilise the temp and feel different.

Re: Aircon question

PostPosted: Thu May 16, 2019 1:36 pm
by linkwater
Auto mode is a setting that allows the unit itself to decide whether it should be running on cool or heat mode. The logic on all models seem to take their time. I usually advise clients to stick to the cool or heat settings.

Re: Aircon question

PostPosted: Thu May 16, 2019 4:34 pm
by 2Sheds
linkwater wrote:Auto mode is a setting that allows the unit itself to decide whether it should be running on cool or heat mode. The logic on all models seem to take their time. I usually advise clients to stick to the cool or heat settings.



Thanks for the reply.
I was just trying out heat mode for the first time.
At 26 deg the Aircon seemed to be throwing out quite a bit of warm air even at todays ambient temperature, but I suppose this was just during the initially phase.

Re: Aircon question

PostPosted: Fri May 17, 2019 2:51 pm
by LHMurcia34
The question is for Mark White re the Air Con......How much exactly does it cost a New Aircon unit to run for an hour on heat and on cool?

TIA

Re: Aircon question

PostPosted: Fri May 17, 2019 3:18 pm
by PeteKnight
An aircon unit wouldn’t normally run for an hour. It would normally run until it has achieved the target temperature, then it would run as often as needed to maintain that temperature.

How long it takes to reach the target temperature, and how much work it needs to do to maintain the target temperature depends on many variables, including the difference between the outside air temperature and the target temperature, the size of the rom, the insulation properties of the windows, walls, floor, roof etc, the power rating of the aircon unit and it’s efficiency rating.

When you first turn the aircon on, whichever mode it’s in, it will use more power initially to reach the target temperature that you’ve set. It may be that after 20 minutes it goes into ‘idle’ mode then after that it needs to do very little work to maintain the temperature.
So, a cost of running 1 hour at full blast won’t tell you anything about what it will actually cost to run it to heat/cool your home.

Pete.

Re: Aircon question

PostPosted: Fri May 17, 2019 3:35 pm
by Steve B
On average 12000btu will consume 1.2kw output of 3.5kw. Costing around 16cents. After around 10minutes the inverter will regulate the power consumed to 600-800w but same output of 3.5kw. Costing 8-9cents per hour.

Regards

Steve

Re: Aircon question

PostPosted: Fri May 17, 2019 5:11 pm
by linkwater
Thanks Steve/Pete, If anyone is curious about how much their units are costing to run, I do have some smart meters that I can let you use for a week to show exactly how much power they consume.


You'll be surprised how little but may be put off putting the kettle on...…..