How Many Solar Panels to Run Air Conditioner?

When you installed the solar panels at your home, you will never use it to charge only one item, and you want to use it to supply much power. For example, some people want to use it to charge their electric applicance at home. Still some guys want to use them to supply the electricity for industry. Here, in this post, i would like to tell you how many solar panels to run the air conditioner. 

The reason is that they pull a constant current, so once you know an appliance power rating in watts, you can match that with 540w solar panel output.

On the flip side, there are still some appliances, like fridges, freezers and air conditioners, are not so straight-forward, as they contain compressors with motors. This means that the power they draw varies and needs to be averaged out.

How Many Solar Panels To Run Air Conditioner?

An air conditioner would need 1200 watts of solar panels for each Ton of cooling capacity, assuming irradiance of 4 Peak-sun-hours/day. A 100Ah battery is recommended per Ton for each hour anticipated running time. This will allow running when irradiance is low and also provide a reservoir to supply motor surge current.

These are the things we need to know before building a solar system to run an air conditioner:

  • Why air conditioners are rated in tons
  • AC power rating (kW)
  • What is surge current and power factor?
  • How long will the air conditioner be running?
  • Are batteries needed to run your air conditioner?
  • What type of batteries are best suited for solar energy storage?
  • How much energy do solar panels generate?
  • Solar panel sizes you’re going to use
  • Inverter sizing (and why you need one)

How Much Electricity Does an Air Conditioner Use?

Why Is AC Rated in Tons and Not Watts?

All air conditioning units have different efficiencies, so if we used their electrical kilowatt ratings for comparison, it wouldn’t reflect their cooling power.

This means that 2 AC units rated at 1.5 kW might not have the same cooling power.

So what is a ton in AC ratings? It represents the amount of cooling required to melt 2000 pounds of ice in one day. It’s commonly known in the trade as a short ton.

The bigger the tonnage, the more air can be cooled each hour. One ton can also be represented as 12,000 BTU/h (British Thermal Units per hour) or 3.5 kW (kilowatt).

This means that a 1 Ton air conditioner has a cooling capacity in Watts of:

(12000BTU x 1055) / 3600 = 3516 Joules per sec = 3516W (cooling)

What Is EER Value in AC?

EER means ‘energy efficiency ratio’ and it tells you how well an air conditioning unit cools. If you divide an ac unit’s BTU number by it’s electrical rating in Watts you come up with a ratio which indicates it’s efficiency.

Another efficient air conditioning unit could have an EER of 11, for example. AC units with an EER rating of more than 10 are recommended for countries or locations with hotter climates.

You still need to know that the EER rating system is based on an outdoor temperature of 95°F, a temperature inside of 80°F, and 50% humidity.

The SEER rating is more common nowadays, as it takes into account an air conditioner’s cooling capacity over a range of outside temperatures – the S means the ratings are ‘seasonal’. 

Lennox are making particular gains in supplementing their designs with solar panel support and this will probably become the industry-standard in the not-too distant future.

How Much Does It Cost Per Hour to Run an Air Conditioning Unit?

This can vary quite a lot and depends on several factors:

  • what is the efficiency of the AC unit?
  • the outside temperature
  • the cost per kWh of your electricity
  • how often during the day you run it
  • how long the AC unit runs

You can look this data now, it can get complicated but is it worth going into all this detail? Let’s examine the factors you need to be aware of.

In fact, it is easy to know that the air conditioning and solar installers have rule-of-thumb guides for sizing systems. One of these rules states that an air conditioning unit pulls around 7 amps for every 1 Ton of it’s cooling capacity rating.

On the flip side, this changes when the Tonnage changes. It’s widely accepted that the relationship of amps vs tons changes as the cooling power increases:

  • 2 ton equates to 15 amps
  • 3 ton equates to 18 amps
  • 4 ton equates to 21 amps

It is better for us to know the aim of sizing and installation. For me, when I am going to design a solar panel installation, I really want to know exactly what’s going on electrically! Now, i have know much about how many solar panels to run the ac. If you still don't know the info you need to know, please leave us the messages to us.

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