The 6 Square Meters Where Radiators Fail The Most

We can forgive a radiator in a living room. It is inefficient, it heats the ceiling, it moves dust, but at least you can live with it. In a bathroom it fails at every single job. Job one is warm feet. Radiator is under window, or towel ladder on one wall. Heat goes up to ceiling in 5 seconds. Floor where you stand barefoot stays 15 degrees ice in January. You step out of 38 degree shower onto 15 degree tile and lose 200 watts through your feet in 10 seconds. You shiver.

Job two is no fog. Radiator heats air to 24 degrees. Warm air holds more water than cold air. After shower bathroom air is 28 degrees and 90 percent humidity. That humid air touches mirror that is 18 degrees cold and instantly becomes fog. You wipe it, it fogs again. You cannot shave, you cannot do makeup.

Job three is dry towels. Towel ladder heats air around towel to maybe 23 degrees. Air dries only outside of cotton fiber. Inside of fiber stays wet for 6 hours. After two days towel smells because it never truly dried.

Job four is no mold. Bathroom tiles are 13 degrees cold in January. You shower, you make cloud of humid air. That cloud touches 13 degree tiles and drops water like a cold beer bottle sweating. Tiles are wet 24 hours a day, grout is wet, silicone is wet. Mold lives on that permanent wet film. You bleach, it comes back, because tiles stay cold.

We stopped trying to fix the radiator in the bathroom. We removed it.

One Mirror That Does Four Jobs

We put a mirror on the wall that is not a mirror. It is a 600 watt infrared heater that looks like a mirror.

It is 60 by 90 cm, frameless black glass, IP65 so you can splash it, glass surface is 45 degrees warm when on. It does not heat air. It shines invisible infrared light, like February sun through a window that warms your face even though air is minus 5. That light crosses air without loss and becomes heat only when it hits something solid.

Stand one meter in front of it after shower. In 60 seconds you feel soft warmth on wet skin, like standing in sun, not like hot wind from a blower. No draft when you are wet, no 2000 watt noise.

Look at the mirror while shower is still running. It is perfectly clear. Physics says water cannot condense on a surface warmer than air. Air after shower is 28 degrees, mirror glass is 45 degrees. Steam touches it and nothing happens. No fog ever. You shave while bathroom is still steaming. No heating wire behind glass, no brown lines, no wiping.

Look down. Floor in front of it was 15 degree ice. After 25 minutes of light it is 26 degree warm barefoot. Tiles on opposite wall were 13 degree ice, now 24 degree warm to lean on. It feels like a warm tile stove.

Hang a wet towel one meter away. Infrared light penetrates 2 millimeters into cotton and heats water inside fiber directly, like sun drying laundry outside. Not air drying outside of fiber, but light drying inside. Towel is bone dry in 40 minutes, bathrobe in an hour, no smell.

Leave door open and that same mirror warms hallway floor 3 meters away because light travels. One panel replaces radiator, towel dryer, mirror anti fog foil and hot air blower.

Why Mold Disappears Without Bleach

Bathroom mold is not a ventilation problem. It is a cold surface problem. You can ventilate for an hour, tiles stay 13 degrees cold and stay wet.

A ceiling infrared panel, 500 watts for a 6 square meter bathroom, or that mirror panel on the wall, shines directly on cold tiles and keeps them at 23 degrees. Now 28 degree humid air touches 23 degree tile and nothing happens. No water drops, no wet film, no food for mold. It is physically impossible to condense on a warmer surface. In 90 percent of bathrooms black dots in corners and on ceiling above shower dry out and fall off by themselves in 3 weeks. No bleach, no anti mold paint, just warm tiles.

Because there is no air movement, there is no dust burning smell. Humidity after shower drops to healthy 50 percent in 20 minutes because warm tiles push water away instead of holding it.

How You Live With It

One panel, 500 to 600 watts for a typical 6 square meter bathroom. One WiFi thermostat with small sensor you put on wall where you actually stand naked, not on hot radiator. One app on phone.

Morning program 23 degrees from 6 to 8 only. Evening 23 from 19 to 22 only. Rest of day 16 degree anti mold mode for 6 cents a day. Weekend house on coast has no water inside so nothing can freeze and burst. You can leave it at minus 15 for three months completely off. One hour before arrival tap ON, arrive to warm floor barefoot and mirror already clear.

It pulses 15 minutes on, 45 minutes off because warm tiles keep radiating when off. Effective 1.2 kWh per day, about 0.30 euro per day, whole winter about 55 euros for bathroom. Silent, maintenance free, 25 year warranty.

The bathroom was never meant to be heated with air. Air belongs at ceiling. You live at floor level, naked, wet, barefoot. Heat floor, heat skin, heat mirror, heat towel. Air will become warm by itself in 3 minutes.