Mike Haydon runs a solar and battery business in Lismore, northern NSW, 24hoursolarpower. Mike has aircon at his on grid house there. Here is some data on the house’s air con.
We may be guided by this data when deciding whether to have aircon with an off or ongrid house, and how to use that aircon if we do have it.
Hi, Michael,
Good to talk to you about air con in our house - we call it, The Bat Cave.
The majority of our on and off grid systems can run air con and do.
Here are some Aircon stats about our house for your readers. We use Solar Analytics to monitor our ongrid system.
Solar panels on Mike Haydon’s house, Lismore, NSW
The house is double glazed, we used magnesium oxide board for wall linings instead of gyprock (which uses 90% more energy in manufacture) and it is insulated. The house is a skillion spilt-level house. We have finished the lounge and living area renovations and we still have the top half of the house which is 4 bedrooms to finish off.
Double glazed doors
It's only a 2-metre walk from outside to inside the house to realise the benefits of all the double glazing to change your experience from an amazing cool house to a hot box. This also, I think, is making the lounge room work harder to keep the internal temperatures down.
Double glazing and magnesium oxide panels
On a 39 degree day, the lounge room is 27 degrees and it feels cooler than that; I think its the position of the monitor which gives a higher reading. That 27 degrees is unassisted with no mechanical cooling.
Here are four images from monitoring of our solar and battery system with data which show the impact of aircon using a low energy setting, just to reduce the humidity. The lower the level of humidity, the cooler we feel.
This image shows the base load of the house most days - 250 watts. This is with 3 DC ceiling fans operating and 2 fridges and some lights. The inside temperature will be 24-27 depending on the heat outside.
This is with the Air-condition in dehumidify mode. The temperature of the house will sit at 25 degrees all day in this mode and it can use 250-400 watts per hour. The room feels the most comfortable in this setting.
This is the aircon on Auto at 23 degrees on the remote. This keeps the room at about 25 degrees on the monitor and you can see is using about 600 watts more than the dehumidify mode.
This is the aircon on maximum cooling at 18 degrees, This will get the house down to 21 on the monitor in about half an hour and then it will use about 1600 watts of energy per hour to maintain that.
The best money spent is energy efficient appliances.
People are better off investing in efficient appliances to reduce their energy demands on the grid or their off-grid system.
Let's talk hot water next! I believe it to be the best battery on the market when the grid is available
Thank you
Mike
How to do it summary
If you have an 'inverter technology' air conditioner switch it to 'dry' or 'dehumidify' mode.
We all know that it feels noticeably hotter on a 30-degree humid day compared to a 30-degree dry day!
When switching your aircon to dry mode, the fan speed and compressor are slow, saving you energy.
Your aircon will also work on keeping the air dry in your home, making it feel like a much more tolerable temperature.
We've tested this out on our air conditioning unit, it keeps our space beautifully cool while only using ~400w per hour compared to ~2500w!
Every air conditioner is different, so test it and try it in your situation to see if it's right for you and if you don't have monitoring on your system for consumption to see the difference in energy use, just go outside and see if the air conditioning motor is spinning slower than before.
Some facts
Location: Lismore, NSW
Number of people living in the house: two adults, two children
Batteries: 12 kWh Nickel Iron batteries
Aircon: Daikon 7.1 kW Cora Series with wifi controls
Roof: colour Silver corrugated iron
Solar panels: On the roof – see photo
Wall lining: Magnesium board uses 90% less energy to make than does gyprock