Hi All,

So I am really new to solar and currently in the process of getting a 5kw SS installed with 5kwh lifepo bat. Budget was constrained so limited the equipment to this. As i understand it, i would be able to run the aircon during the day off PV depending on the other loads in the house on at the same time? my question is at night or specifically, during loadshedding, how much of the battery would I use by running the aircon for about an hour? its an older aircon and not an inverter but other than that, i have no clue on how much power it would draw. anyone able to provide an estimate of the percentage of my battery that would be used just for the aircon?  

Hey @ZCS

On the aircon there should usually be a tag that shows the specs. On that tag it should show the power usage usually watts or watts per hour requirements.

Hard to say exactly without knowing the exact make and model, or the rated power.

Just a general google search indicates a 12000 btu could use between 1kW and 1,5kW of power. Let's assume worst case your older model is at the lower end, then your 5kWh battery should last for around 3 hours and 20 minutes if it's doing nothing else. Rough estimate it will chew through a third  of your battery reserve in an hour, and around a fifth if you're lucky.

You would have to put the aircon on the essential load output, though, if you keep it on the non-essential side it should not function during loadshedding.

Thanks @GreenFields. appreciate the feedback.

the big depend is what is the temperature when you run the invertor. worst case is as above. However most AC's will run and switch off then run and switch off. Time running depends on how much the temperature differential is between the temperature outside and the temperature you want the room at and also how big the room and the insulated properties. Given it is at night it is likely that your AC will run a 50% duty cycle (on /off 50/50). Then you likely find that it will run double the time. What you must consider though is that the question you are asking is more of a "how long is a piece of string" type of question as the above factors assume you are not using the invertor for anything other than the AC.. and also that its not a good idea to cycle your battery 100% depth of discharge...