Solar Dryer concept sketch

After seeing Miele's horrifically complex design (link in previous post) I thought I would put a sketch together. Time to build a proof of concept now I have the rough layout in mind.

The heat comes either as waste from our outdoor gas blower (Brivis Buffalo) or the solar reflector underneath the tumbler unit.
Motion comes from a sub-10watt motor mounted on one of the four jockey wheels (shown in yellow). It could be conventionally powered or solar - as it's power is tiny.
Airflow comes from either a solar fan or a solar chimney (cold air is drawn up and heated, so rises and pulls through).

Moisture could be condensed and captured.

I might need a heat exchanger if the waste gas smells of CNG.

I like the idea of a square tumbler to give churning to the clothes, and is removable as a washing basket.
Ergonomics need thinking thru, as do pinch points...

Hope it makes sense.

Solar Dryer Ideas

A dryer is just a heater and a motor to tumble the contents.

Looking for alternatives around my home:

Heat Sources:			Motion Sources:
Fridge Waste Heat	Too small		Mains Elec Motor	Prob ok, low watts
Solar PV Heat	Too expensive		Hand Crank	Convenience
Solar Radiant Heat	Need a site close to house		Solar pump	Too complex
Gas Heater Waste Heat	Minor Gas smell?
Electric Heat	Currently the problem

Thinking about it some more, our gas heater outside discharges a lot of waste heat, so it's the candidate. And it runs on days when you can't use a clothesline.

A small idler motor run from mains power or DC would be ok as it would need only 50 watts or so. Thats not a lot out of the 4000 watts our dryer uses.

I think it would be convenient to make it so the washing basket becomes the tumbler. I hate hanging up washing on lines, which I suspect is why some people use dryers on sunny days. And lots of everyday items come out good enough to not need ironing. The device would need to be ergonomic with no risk of pinch points or combustion if too hot at a point.

You can say 'lazy' - but in the world of management we call this 'efficient'. :P

**Addendum 5/8/11: Looks like Miele has come up with a horribly complex solution - as only the great over-engineers could. Lose further points for integrating it into the building...
http://www.gizmag.com/miele-solar-heated-dryer/19680/

Energy Use - typical values at home

We've been thinking of ways to reduce our dryer usage at home - if you look at the biggest item down the bottom you'll see why:

Item	Hourly Watts
6 Cree LED Downlights	18
6 Halogen Downlights	50
Electric Blanket	75
Desktop PC	250
LCD TV	300
PS3	350
Washing Machine	350
Radiant 2 Light Bathroom Heater	500
Fridge	750
Aircon (small)	750
Espresso Machine	750
Kettle	1000
Vacuum	1000
Clothes Iron	1000
Microwave	1000
Oil Filled Radiator	1500
Aircon (big)	1500
Clothes Dryer	4000

The above typical values are per hour. Kettles and microwaves look to be high but they don't get used much.

But when it comes to clothes dryers you don't have many options but to use them for a long time when it is wet outside. Searching online results in lots of suggestions to use your clothes line. Which isn't any help at all if it's raining.

it's impossible to find an 'efficient' clothes dryer as they are really a big electrical resistor to make lots of heat, with a small motor to roll the clothes around.

But I have some ideas for later.