Ditching the shower fan

By fitting a lid on the shower, exhaust fans are not needed when showering. John Rogers describes this simple retrofit, using both a commercial product and a great looking DIY version.

When building my energy efficient home I concentrated on sealing gaps, maximising the insulation, facing the daytime room windows north, installing double glazed windows and doors and going all electric.

One thing that I didn’t do was to fit an air exchange system for air exhausted from the house. My thinking was that most of the exhausted air was from the south side of the house and was mostly unheated air. I therefore ducted the bathroom, ensuite and kitchen exhaust fans outside and allowed the toilet fans to exhaust into the roof space.

Little did I know that there was a much better solution regarding my two showers. I was spurred into action when my nephew gave me a brochure that he picked up at the Electrify Boroondara Expo, about the ShowerDome product. This product simply places a lid on a standard shower cubicle which, by not running the room’s exhaust fan, prevents moisture from leaving the shower cubicle, thereby preventing the mirror and other surfaces in the room from fogging up or simply getting wet.

I purchased a ShowerDome for my standard shower cubicle in the corner of my bathroom as the extra height provided by the dome was required. For my ensuite shower I installed a piece of PVC at the top of the tiles above the shower, which is in an alcove, with a second piece of PVC filling the gap between the door and the PVC “lid”.

My experience is that my converted showers are more comfortable without the breeze and noise created by an exhaust fan and with absolutely no moisture on any surface outside of the shower. Even with the exhaust fan running my bathroom mirror previously fogged up. Not now, and with no fan running.

Apart from increased comfort, other advantages of this passive solution are the cost saving of not running an exhaust fan or mirror heater or purchasing these for rooms without a toilet or bath, not sucking cold or hot air into the house to replace exhausted air, and using less hot water, as it is not necessary to counter the cooling effect of the moving air caused by the fan. ShowerDome also points out that mould and mildew will be reduced in the bathroom, with increased safety from fewer wet surfaces, reduced maintenance and improved air quality.

I have learnt to keep the shower door closed while waiting for hot water to reach the shower head and after the shower while drying off and dressing. I leave the shower door open after leaving the room to allow the cubicle to dry.