Building Stevenson Screen

I am sure that many of you here have made some form of Stevenson screen. I have spent a couple of months trying to find one that is affordable, without success. I have now started looking into the possibility of making one. I did some sketches of louvres and took them to local joiners but their offers were too expensive. I am now looking at purchasing louvres to fit into a simple wooden box.

My present problem is finding the right louvre. Looking on the Internet, the variety of louvres on offer is rather offputting, with panels of, say, 300 mm x 300 mm. Firstly, there is the choice of materials with aluminium, steel, wood and “plastics”. The latter are obviously the least expensive but the type of plastic is rarely specified and I could well imagine that many cheap louvres would not last very long in the Cyprus sun. Prices range from less than five euros to many tens of euros each. I also find it difficult to judge the opening percentage from the little illustrations that vendors put on their websites.

Has anyone who has made their own screen taken the plunge and found louvres that have worked well? Obviously, I don’t want to pay a king’s ransom (otherwise I would buy a ready-made screen!). Any advice, preferably from a European source, would be welcome

Devil,
I’ve not made it, but one here in the states was made with relatively cheap bi-fold doors meant to be used as closet doors to allow ventilating air to flow through the slats. I’ve looked at some do it yourself stores here hoping to make one this summer. and far less expensive and time consuming than making them (unless you own a woodworking shop and are good at using the tools).

The question is, do the instruments inside get the same ‘environment’ as an official Stevenson Screen, with so many cubic feet of air exchange per mph of wind speed, or volume of interior space that was originally designed into the ones made back when this was invented, or will the same normalization of readings occur no matter how you build it? I don’t have an answer to that, but suspect it isn’t critical since I’ve seen the small sized one, and other that look like the just doubled the plans from the smaller ones.

I know there is a thread discussing painting the inside black rather than white.

I’d be curious, with cheaper solar panels, if anyone has made a FARS out of a Stevenson Screen to improve airflow even more?

Good luck and of course we expect updates and photos as you progress! Dale

Devil,

like Dale I also used a wooden louvered bifold door, like the type you’d use to cover a closet or a hall way. I chose a 30 in model, meaning each side of the bifold is 15 inches.
Was a bit tricky measuring and figuring out where exactly to saw it, but I got there. I used one section as the ‘door’, using the hinges from the bifold. It’s worked well, given the heat in the Sonoran Desert, - since 2007 - tho’ it is failing a little in places and I’ve had to do kludge-y repairs… I used a white oil-based paint to cover it. Next one I plan to use right-angle brackets to hold it square and better together…

HTH
Ken

Most louver doors that I’ve seen in Home Depot etc. appear to have too much overlap to allow good air flow :frowning:

Thanks everybody. This was one of my worries that cheap louvres restricted the airflow too much. Unfortunately, in this country there are no decent outlets for do-it-yourself project materials, which means that whatever I choose will have to be imported from Europe, sight unseen.

Dale, I tend to agree with you that the dimensions of the screen are not critical, but that the airflow is probably important, so that the “aperture” of the louvres is possibly to be considered.

Another point that I am pondering is that, in summer, the air temperature can easily exceed 40

I don’t think it would be difficult to make a louvered screen out of wood. Wood for the slats can bought in 8/10 foot lengths and be cut to length. The tricky part is making the corner posts. Buy square section lumber and either cut grooves for the slats with a router, or table saw with dado blade, or cut lozenge shaped spacers out of thinner lumber with a chop/miter saw and pin/glue to the corner posts.

The challenge for me would be to get slat wood that will stand up to the climate/solar radiation and not warp into spaghetti after one summer :frowning:

Often thought about doing this, too, but the thought of double louvres on all sides is quite daunting!

Fan motor on top of the screen in the first pic here is for the psychrometer, not FARS!

Good Australian Met screen comparison test here. It always surprises me how well the small, only 19 cm diameter, Vaisala beehive screen performs.

Yes, i think all Vaisala instruments/sensors are pretty damn good :smiley:

Another point is that most commercial 400-500 mm louvres are metal. They could attenuate wireless connections, possibly block them altogether. Guess wood or plastic would be better. I still haven’t found an affordable solution :frowning:

Here’s one that I made years ago out of window shutters. It worked well.
https://www.weather-watch.com/gallery/displayimage.php?album=search&cat=0&pos=1

The gallery url’s don’t work that way, you’ll have to link the images directly:

https://www.weather-watch.com/gallery/albums/userpics/14552/normal_IMG_0537.JPG

hi

I made a small screen box, it’s very easy to make
To make the wooden double louvre doors slats , you need a length of 90

I think using the dowel is great idea, it will add some strength to the 90 degree wood molding :thumbright: