Hi

I like near the Kruger and we get a lot of sun. It's also hot in summer at 45 deg! We're building a new house and I want to plan the aircons and solar carefully.

I'd like to run solar panels to power my aircons during the day, and have a small battery for LED's and fans at night.

Is there a way to do this without a large battery system? I.e. I want to configure to aircons to only run when it's sunny and hot!

1) Would you recommend a Sunsynk 8KVA to power the lounge aircon during the day?

Later if we need, we could always add another 8KVA inverter if we want to power more aircons in the bedrooms.

2) Any particular aircon brands that are energy efficient I should look at?

3) I want to try have a small battery for some LED's and ceiling fans in loadshedding. I don't want a large battery bank to power aircons at night.

What's the best setup for this?

Thanks in advance! I really appreciate any insight and help.

P.S. Far too many companies just want to sell their largest system and I want to not overspend on batteries we don't need. When it's hot and the sun is shining, I want it to power my aircon!

 

Would I need a 24v or 48v battery?

52 minutes ago, AlexanderR said:

Would I need a 24v or 48v battery?

Will you be having grid or planning to be off grid in future? 

10 minutes ago, Scorp007 said:

Will you be having grid or planning to be off grid in future? 

We will still use the grid, but would prefer at some point to reduce our usage and rather use more solar.

Would this be a good option for the inverter: https://powerforum-store.co.za/products/sunsynk-sun-16kw-single-phase-lv-hybrid-inverter

1 hour ago, AlexanderR said:

1) Would you recommend a Sunsynk 8KVA to power the lounge aircon during the day?

 

21 minutes ago, AlexanderR said:

Would this be a good option for the inverter: https://powerforum-store.co.za/products/sunsynk-sun-16kw-single-phase-lv-hybrid-inverter

I think you need to give more information about your power consumption in terms of all the devices you're using, and when, or how long, or in terms of kWh consumed per month. If you're staying on-grid, and what size of main circuit breaker have you got?

It's quite possible to divert solar power to the aircons by day, and configure it as non-critical loads without battery backup.

In this ballpark of Sunsynk inverters you're looking at 48V batteries. You don't have to go to town and be 100% off-grid self-sufficient, there is also a middle ground that you can start with and maybe upgrade later. It is possible to under-size the amount of batteries you've got connected, if you set up and configure it on the inverter, and if you accept the limitations that brings.

The 16kW is probably bigger than what most average homes need, most could get by with an 8kW or 12kW. But again, without knowing your actual power usage, it's not really possible to say.

 

34 minutes ago, GreenFields said:

 

I think you need to give more information about your power consumption in terms of all the devices you're using, and when, or how long, or in terms of kWh consumed per month. If you're staying on-grid, and what size of main circuit breaker have you got?

It's quite possible to divert solar power to the aircons by day, and configure it as non-critical loads without battery backup.

In this ballpark of Sunsynk inverters you're looking at 48V batteries. You don't have to go to town and be 100% off-grid self-sufficient, there is also a middle ground that you can start with and maybe upgrade later. It is possible to under-size the amount of batteries you've got connected, if you set up and configure it on the inverter, and if you accept the limitations that brings.

The 16kW is probably bigger than what most average homes need, most could get by with an 8kW or 12kW. But again, without knowing your actual power usage, it's not really possible to say.

 

Sounds like a good guideline. Start with the 8 or 12kW and if the need is there then add a similar 2nd unit. 

The power consumption would be the key as you stated. 

@GreenFields & @Scorp007 - thanks for the detailed response. I really appreciate you taking the time to help out. If you need any more info, let me know and I'll try get it.

______________________

Current Info

1) We currently use 1000 kw/h per month (1000 units) from Eskom. This is in the house we're renting.

2) We're not really running the main aircon.
______________________
New House Aircons

• Lounge Room Size: 12m long x 7m x 7m high (thatch) - I need to work out what size aircon to install here.
• 3 Rooms of 4x4 (Bedrooms)
• 1 Room 6 x 6 (Main Bedroom)

That's what we'd like to cool.

______________________
New House Other

• 2 x ITS Heat Pumps
• Pool Pump
• Ceiling Fans - 4 Run Continuously to Circulate Air
• Gas Stove & Oven

______________________

GOAL: To first get the sun to power the lounge aircons, then as we get funds, expand to power the other aircons and then the whole house. Have a little battery so if there's load shedding at night, we can run our ceiling fans.

That's Why I Was Thinking:

• Sunsynk 16kW Single Phase LV Hybrid Inverter - has capacity, if we want to run 3 or 4 aircons later at the same time.
• HUBBLE AM-2 5.5KWh 51 Volt Lithium (unless there's a much cheaper one you can recommend)
• Not Sure How Many & What Panels to Get to Run that Large Lounge Aircon

 

______________________
Questions

1. How many KW does a larger aircon normally use? It has an initial draw then a huge drop off with inverter type ones.

We'd need a 32 or 36 BTU for the lounge: https://www.jet-air.co.za/download/aircon-products/q-plus-inverter.pdf (https://www.jet-air.co.za/midwall-aircon.html).

2. Do you know any energy efficient larger aircons?

3. Are there larger aircons that can be piped into multiple rooms? (Rather than having 3 wall mounted ones, we have one larger one that pipes into the rooms)

______________________
 

18 hours ago, AlexanderR said:

2) Any particular aircon brands that are energy efficient I should look at?

LG Dual Inverter (pricey, but very power efficient)

Work out the BTU needed for each room

Say the room size is 5x5 meters, use 5x5=25 then x600 and this will give you 15000 BTU's

Round this off to 18000 btu as you don't get 15000btu and 12000 btu will be way to small

18 hours ago, AlexanderR said:

Would I need a 24v or 48v battery?

Go for 48. Lighter cabling, better choice of batteries and inverters.

11 minutes ago, Warlok said:

LG Dual Inverter (pricey, but very power efficient)

Work out the BTU needed for each room

Say the room size is 5x5 meters, use 5x5=25 then x600 and this will give you 15000 BTU's

Round this off to 18000 btu as you don't get 15000btu and 12000 btu will be way to small

Thanks for the tip. 

1. We'd need a 32 or 36 BTU. Any ideas for this range?
2. Any other ranges to look at apart from the LG Dual Inverter?
3. Would you go for a larger 32 BUT or 2 x 18 BTUs?
4. Can we have one powerful outside unit and have it power multiple rooms inside? Do you know of anything like this https://samsungair.co.za/product/samsung-free-joint-multi-airconditioner/

The brand will be your personal choice. Samsung is an excellent air-conditioner.

After 30 years of air-con installations, the only ones that outlasted all of them is LG

I'm not a LG sales person, I have a Carrier inverter in my lounge. 🙂

LG was just a bit to expensive for my budget

I've installed a unit similar to the Samsung one and for 2 years no problems

Then a lightning strike later and the whole building had no air-conditioning (a very pricey repair)

I would personally go for individual units for each room.

Installing 2x18000btu to get to 36000btu will cost way more than just getting a 36000btu

As far as brands, please stick to good names;

Samsung, LG, Carrier, Panasonic, etc....

Lately, Midea, Gree and even TCL made good air-cons. But the king for power consumption and performance is still LG

2 hours ago, AlexanderR said:

Thanks for the tip. 

1. We'd need a 32 or 36 BTU. Any ideas for this range?
2. Any other ranges to look at apart from the LG Dual Inverter?
3. Would you go for a larger 32 BUT or 2 x 18 BTUs?
4. Can we have one powerful outside unit and have it power multiple rooms inside? Do you know of anything like this https://samsungair.co.za/product/samsung-free-joint-multi-airconditioner/

A rough idea would be 100BTU per cub m of volume. 

My only experience is with Jet Air inverter. Working very well for over 5yrs 

18000BTU uses about 1740W input but the rating is given as 2400W input for cooling. It also has WiFi connectivity as I think most these days do. 

 

New place has 3 phase or single phase power? 

and this is just my personal opinion regarding one high power Inverter or smaller Inverters in parallel.
If a failure occurs on an Inverter and there is only 1, then you are left without solar energy.
With 2 or 3   5kW Inverters in parallel if one fails, you can continue to use solar energy albeit at a reduced available energy.  

4 hours ago, AlexanderR said:

GOAL: To first get the sun to power the lounge aircons, then as we get funds, expand to power the other aircons and then the whole house. Have a little battery so if there's load shedding at night, we can run our ceiling fans.

That's Why I Was Thinking:

• Sunsynk 16kW Single Phase LV Hybrid Inverter - has capacity, if we want to run 3 or 4 aircons later at the same time.
• HUBBLE AM-2 5.5KWh 51 Volt Lithium (unless there's a much cheaper one you can recommend)
• Not Sure How Many & What Panels to Get to Run that Large Lounge Aircon

Personal 2c. I think you could get far with just the 8kW Sunsynk and max it out with 10400W of panels, as a minimalist starting setup. I'd suggest the AM5 Hubble batteries rather than the AM2 though.

That would be putting the aircons as non-essentials, if you're using as above 1740-2400W per 18000btu. That could provide power for 3-4 inverters at once most of the time. In this setup you'd stay connected to the grid to help you cope with the start-up surges and cloudy spells anyway, but after that the inverter can direct up to 8kW, and charge the batteries above that to 10kW.

But if you add in running the pool pump and two heat pumps, say another 1kW plus 2 x 1.25kW, the 8kW would be a bit lightweight to cover that all at once, so you'd either have to upgrade to maybe the 12kW, or else be willing to shuffle the time schedules for aircons versus pool & heat pumps, or be satisfied to buy some in from Eskom. The heat pumps I think are better on AUX/Smart-Load, so you have a backup plan for when the grid goes down, similar to how you'd swap your aircons to fans, but the pool pump could just stick as a non-essential load, and be prepared to run it later when the grid is back.

I think the 16kW inverter is a bit much, not needed, especially if you'd have to upgrade your Eskom supply to 80A. I'm assuming it's all single-phase. My gut feeling is a 12kW would be about the sweet spot, and then I'd match it with a Greenrich as a 1.5C battery, in case you'd be interested in going off-grid that'll help you better with surge capacity.

I will respond and research all suggestions in detail! A massive thanks to everyone who's taken time to help out. I really appreciate it.

Not sure if it's important, but the estate only has a 40amp power grid.

48 minutes ago, AlexanderR said:

I will respond and research all suggestions in detail! A massive thanks to everyone who's taken time to help out. I really appreciate it.

Not sure if it's important, but the estate only has a 40amp power grid.

I think it is important if you are limited to an inverter that is less powerful than the grid. Maybe one of the installers can comment here. My fear is that you may be limited to an 8kW inverter or less just to get a certificate of compliance, as long as you want to be on the grid. But don't quote me on it.