Wind powered clothes drying project.

Do-more

I'm living in the South of Sweden and about to new build to passive levels (but not certified).

In the summer months we use the tried and tested wind and solar powered clothes line for drying cloths.

But the outdoor drying season is pretty short here, maybe 4 months, so I'm looking at possibilities for a wind powered clothes dryer for the remainder of the year.

I'm inspired by a piece of equipment which is popular here:



It's a metal drying cabinet with electric heating and a fan which is used for clothes drying in the winter.

I'm thinking of something similar (maybe convert a 2nd hand one) but powered by a small 12v wind turbine. I would also have a 12v heating element in the hot water tank as an alternative dump from the turbine, especially in the summer.

Waste heat would be recovered by the MHRV in the winter so would help with the overall heat load of the house.

One alternative is not to have a cabinet but to heat the entire utility room with a resistive element powered by the turbine but I'm guessing that the MHRV will extract the air from the room too quickly and never allow the temperature of the room to rise enough for clothes drying?

I haven't done any wind readings on the site yet but the wind turbine will be located close to the gable end of the house where the utility room is planned to be and is approx. 75 metres from the coast. The name of the village we live in translates as "The windy place" in the local dialect so I'm pretty confident we have plenty of wind power to tap. (There are quite a few commercial wind turbines in the area also)

It's as much a fun project as anything. Maybe a little hair-brained but anyway I thought I would bounce the idea here and see what people think?

rural_red

I have a client requesting a drying room beside their utility. It is to be heated and fitted with an extract through the MVHR. In terms of worrying about the heat escaping too quickly; I wouldn't worry.

Heated Air expands taking on more moisture immediately and if this is extracted it only ensures that the flow of moisture is always out of the utility. There will only ever be a certain amount of moisture which will be the background Relative Humidity(RH) of the indoor air and that of the clothes in question. Heating and Extracting at a constant rate will dry this area out. If you continually take this mositure and extract it the clothes will dry. But make sure you extract from a high level.

The worry would be that you will need to calculate the quantity of moisture and the (minimum) temperature of the air that you are extracting to make sure that you are not creating problems of condensation in the ductwork. You will also need to make sure that you undercut the door onto the room to allow new air enter the room to replenish the supply and you will want to make sure that the heater is at a low level below the clothes. A skirting heater may be a good idea. So now we have a flow of warmed air taking on moisture while passing from top to bottom of the room and extracted out.

Also ensure that you finish the walls, ceiling and floor with tiles or similar impermeable layer so that you are not creating surface conditions that would encourage mould growth. If you have the extract on all the time, this shouldn't happen. The heater could be on a demand basis.

In order to cut down or reduce the heating load, why not build the room with a rooflight overhead and take advantage of solar gains. The only issue here would be that you will need to be wary of condensation on the rooflight itself. A triple glazed rooflight facing south with adequate ventilation extracting below the line of the rooflight SHOULD be safe? You will also need to calculate solar gains generated in the worst case scenario. You may end up with a heater as back-up!!

al2009

This product was developed in Cork, possibly a more ready to market type product?

<SNIP>

alec




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Do-more

rural_red wrote: »

Also ensure that you finish the walls, ceiling and floor with tiles or similar impermeable layer so that you are not creating surface conditions that would encourage mould growth.

Thanks for all those pointers rural_red, you could look at this wet room paint for your clients drying room, it's expensive but probably much cheaper than all that tiling and particularly effective for the ceiling.

Thanks also Alec, looks like an interesting product any idea what the price will be?

al2009

No, i've no idea on price, i think it is getting ready for full production, clever idea though.

alec

quentingargan

Although you see it done, connecting a heating load directly to a turbine isn't the most efficient way to use a turbine. If you just connect a resistive load, then the energy output is directly proportional to the voltage, or rotational speed of the turbine. However, most turbine blades produce energy that has a more exponential ratio. Attached is a typical "power curve" showing the power that can be harvested from the blades as the voltage rises. Also, at start up, the resistive load may prevent the turbine spinning at all - you will see on this curve, that no power at all is harvested until the turbine reaches 20% of its peak voltage.

You would need a controller which prevented the load coming on until the turbine got up to speed, and then incrementally increased the load. Ideally, the heaters would be controlled using pulse width modulation via a mosfet, and you would need a small PLC to manage that. I've done this in a totally different application, and it works OK.

But if you just connect a heater to a turbine, you may be disappointed at the results.