The V4 wireless remote-control model allows you to control the functions of the fan. You can turn the fan on and off, adjust the fan speeds ¼, ½, ¾, full speed, set timers and force the unit on/off when the temperature is above or below the 25°C auto shutdown. Australian summers continue to get hotter and so do our homes. A great way to make your home or business cooler in summer is to use solar roof ventilation like the SolarKing solar fan. Roof temperatures in Australia during summer often reach 50 to 70°C and the best way to reduce these high temperatures in to install the SolarKing roof fan Many homes already wind driven “whirly birds” installed on roofs. Whirly birds rely on highs winds to produce any benefits and even then they only move around 100CBM per hour for each unit. Compare this to the SolarKing that moves 2100CBM per hour, there is no comparison. The SolarKing solar exhaust fan uses the sun and only starts working when your roof space reaches 25°C so as not to remove warm air in the winter when it is needed to keep your house warm (whirly birds operate regardless of the temperature. When the sun disappears in the evening the SolarKing will stop ventilating but at this time the roof is now cooling naturally with the reduced temperature as the fan has been extracting heat during the day. Have you ever noticed how the lower level of a 2 storey home is always cooler than the upper level? This is due to the upper storey blocking extreme heat from the lower level. The SolarKing solar roof ventilation fan does the same thing, the fan replaces the hot air inside your roof with the cooler outside air. This greatly lowers the extreme heat in your roof pushing into to your living space. You can also add closable vents in the ceiling of your home that can be opened when a cool change comes through to draw the cooler air in through your open windows and doors. Normally you would position these vents near the centre of your home to extract maximum hot air. This air is then extracted along with the hot air in your roof by the SolarKing solar fan. If are looking to make a big change to your comfort levels this summer and looking to reduce high energy costs of using air conditioners. Let the free power of the sun to do the work for you and use you air conditioning a great deal less. This latest V4 wireless model carries all the updates from the V3 model that has a DC power connection so you can connect the optional 15V/240V AC power supply to let the fan operate after the sun goes down. The unit will switch to the optional power pack automatically and when the solar input level increases again the unit will switch back to solar operation. The unit will still turn off automatically when the temperature drops below 25 degrees. The V4 also carries over the constant speed motor to prevent any sudden increases and decreases in fan speed. This new V4 wireless model, now has last setting memory without the optional power supply being connected. Anti mould function, the unit will automatically power up during the day for 15 minutes to ventilate the roof. The V4 model now has electroplated steel body and brackets along with the existing aluminium flashing and aluminium fan cap, fasteners are stainless steel.