Q&A: Electric bathroom heating

Q

We are ditching our gas connection as part of a major renovation and switching from ducted gas and evaporative cooling to multiple reverse-cycle units that will heat the living and bedroom spaces only. What is the most efficient and greenhouse friendly way of providing heat to bathrooms? I have been looking at a Clipsal strip heater as well as a unit from Heatstrip.
—Ben Purcell

A

Efficiency of electric heaters are all the same, i.e. 100% of what goes into them turns into heat; it’s just the type of heat that matters. The high-temperature radiant heaters like the Clipsal and similar have a near-instant heat but can overheat you if you are too close. They also have elements that eventually burn out, usually in the middle of winter when they are being used the most, in my experience.

The lower temperature units like the Heatstrip are still higher temperature than ‘true’ far infrared heaters, but they have a similar effect. You can get an idea of running temperatures by looking at how large the panel is compared to its wattage rating. For example, my true far infrared heater (a Heat-on 600 W DIY panel at www.heat-on.com.au/DIY.asp) is 600 watts and measures 900 x 600 mm, so 1111 watts per square metre. The Heatstrip 800 watt unit, for instance, is 624 x 235 mm, so 5455 watts per square metre, so it would run at a considerably higher temperature.

Between the Clipsal and Heatstrip, I would go for the Heatstrip if the budget allows, as it should last pretty much forever, looks nicer and should feel nicer on the skin as well. But the average high-temperature strip heater like the Clipsal is going to be about a tenth of the cost to buy, so you have to weigh that up as well.

Most bathrooms end up with the common combined heat lamp/light/fan fittings; however, they cause a large ceiling penetration that can’t be insulated over (it’s usually better to avoid ceiling penetrations), although being a square box, you can insulate up to them effectively. The heat lamp fittings in many of them are usually fairly well sealed inside the main box, although even the draught-sealed units such as the IXL Eco Tastic have some small manufacturing holes in the metal case that allow some air bleed into the ceiling, so it’s worth sealing those before installation.
—Lance Turner