UK can heater project HELP required! please

Hello guys, I have since last year wanted to build a pop-can air heater and have been collecting cans for a while, only know have I got my act together and trying to complete the project but have no building skill at all or electrical skills so will appreciate any help you guys can give to make this as efficient as possible. I'm trying to heat a converted garage which is a home theatre but the room just does not keep heat in so we are always running the heater, its build from concert blocks so there is no way to insulate them and it has a flat roof. May be in a year or two I will strip it back

Here is my plan:

To build a box around 150 - 180 x 60cm and have some way to put a computer fan in it to blow the air (not sure how to power it as of yet).

I was thinking of using Plywood to build the frame as MDF is not as strong but any suggestions to keep costs down are appreciated (ill be using http://www.diy.com/nav/fix and http://www.wickes.co.uk/building-materials/icat/buildmaterial/ to buy the wood so anything you see on there suitable).

Will get acrylic sheet from the above suppliers, they come in 180x60

I got the cans from home and family and plan to do 10 cans by 7 which is 114x48cm in total but can go more if I don't cut the sheet of acrylic down or make a small box. I have siliconed what you see in this pic but need a few more cans and have sealed with Fire Retardant Silicone.


I've just ordered:
Thermawrap Loft Insulation 400mm x 5m shown here which I hope will be ok to insulate the inside and sides of the box.
2 x 400ml cans of matt black heatproof spray up to 650 Deg Cel to spray the cans and box.
Aluminium Silver Foil tape (3m x 50mm) not sure where I will use it but maybe to line insides panels.
3m of Aluminium foil flexi ducting.

I'm not sure how big to have the top and bottom air intake and out put channels (don't remember what the correct name is beginning with H) but I want to use a 10cm ducting connector which I need to buy.

I also have a 120mm PC fan but have no idea how to wire it or power it or where it should be placed in the assembly.
I'd also like to be able to get a digital temperature readout but don't have a clue how to do this and have a way for the unit to come on when the unit temperature goes above a set temperature.

Well that's all the info I have for now but hope its enough and hope one of you guys can help with the technical side of things.

Regards

Ive only tinkered with this so please take what I have to say with a grain of salt. My understanding is that you will be much better off having a lower temp air 90F blowing out in a larger volume than 180F in a smaller volume. Depending on the space size you are heating this will really come into play. I put my pc fan at the exhaust and I had 120F heat coming out. It did ok in a 10 x 12 room that already had alot of solar gain due to windows. The idea is to get as much warm air out of the unit to make room for cooler air like a radiator, thus putting on the exit point. I hooked my pc fan up to an old power supply box from a pc that converts the ac to dc, you could also use a 12 v battery Id imagine. If you can design it so your intake and outflow are able to be tweaked that owuld be best for experimenting. My 2 cents.

I know I'm probably a bit late on the topic, but I just found this thread and figured I'd lend my opinion. I have been looking at building one of these for a while now. I'm not one to jump into any project, so I have been doing research and from what I gather, you don't necessarily need a fan if you design it right. This is just one website that explains the process: http://faircompanies.com/blogs/view/building-a-solar-heater-with-recycled-cans/

Good luck if you haven't finished it yet!