'Dual Fuel' towel rails - recommendations and comments wanted

I would sat definitely do it. When the bathroom was redone, we decided at the last minute (but not too late) to add electric heating to a ladder-type towel rail that was being put in. It may even have been purchased separately - a long pointy sticky thing that you install by unscrewing the bottom plug on the towel rail, screwing in a dual fuel elbow, and then screwing in the heating element.

Screwfix for example has the required bits.

Very handy for getting towels dry during the summer when the CH is off.

Side note: towel rails should be white not chrome finish for best radiation.

I don't know what types your central heating or shower is, but I'm very happy with the "single fuel" towel radiators in my house. They are plumbed into the central heating primary side, before the diverter valve, such that they are heated whenever the boiler fires up, regardless of whether it's for heating the radiators or replenishing the hot water in the water storage cylinder.

So, for example, by the time we've finished a shower in the summer, the towel radiator has heated up to provide cosy warm towels, and to dry the towels again.

As I said, it works well for us. And there's no need for an electric element (which would need to be on a timer to heat up sufficiently in advance of you needing the radiator to be warm).

Unless you live in a flat, outside is even better :-)

Matt black surely ?, but when draped with wet/damp towels only conduction is relevent anyway ?.

I'm talking about towels dampened by using it to dry of a yooman body after it's had a bath.

Black would look ugly and intrusive; the emissivity of a white finish vs. black is small compared to how bad chrome is.

Our boiler is usually comletely off during the summer, we just use the immersion heater. (It's an LPG/gas-in-a-tank boiler so isn't significantly cheaper than electricity)

Personally, during the summer, I wouldn't want such towel rails to get hot just because the boiler is on. I want them to be hot when I want them to be hot. A switch to effect that by shoving volts through a heating element is the best way to achieve that goal.

In the winter that is not used, and the ordinary CH water circulates and heats the rail that way.

While it's a fact that metals have low emissivity, that's only true for super-clean surfaces. It only takes 20 microns of any kind of oil, finger grease, body fat, random airborne contaminants, etc, to raise the emissivity significantly towards the 'black' end of the range - from memory 0.2 for clean metals, 0.8 for the 20-micron contaminated surface.

It's why painted surfaces have high emissivity irrespective of the colour, the radiation taking place more from the paint binder than the pigment due to the '20 micron effect'.

It is a little known fact that the majority of heat generated by 'radiators' is not radiated.

It is convected.

It is another little known fact that heating things does not dry them. It is heating the air moving past them so that it can carry away the moisture, that dries them.

Now apply those facts to towel rails..

It does 3 things

1. It lowers the RH of the air, since maximum absolute water vapour content rises a lot with increasing temp. Ie it dries the air
2. It causes the air to move past the wet thing
3. Higher temp also increases rate of evaporation

If what you really want is towel drying, a small fan is far more effective, and not a total waste in summer.

NT