The Mother Earth News Solar "Heat Grabber"

Henrietta,
Re: security for the windows. There used to be small brass(?) safety gadgets for windows if you wanted to leave them open a little without anyone being able to open the window all the way. I don't know what they are called, but old-time, vintage stores should have them. You basically open your window to where you want it, screw one of these things on the upper part of the window (the wood around the glass)just above the lower window. To lock the lower window down, there is a little swivel knob that you pull perpendicular to the window. It creates a stop. The window can't be raised. If you push the little knob flush to the upper window, then you can push the lower window up as far as you want.
Sorry I can't remember the name of these things, but I bet someone who's been around awhile fixing windows or installing the older type windows would know.

Regarding the safety of having glass in this project - I too am concerned because I have 2 cats and their nosiness could be dangerous if they were to jump onto or against this. I like the clear polycarbonate idea though.

Excellent update on the solar window heater! The design has evolved nicely since I sketched out the idea for a material handling salesman from PA in late 1976. My original version used half-ht aluminum beverage cans soldered to an aluminum isolator plate, encased in a plywood box enclosure with single strength glass. I didn't pursue it commercially but saw an identical heater offered for sale in a newspaper ad the next fall. This new MEN version, while perhaps not delivering as much heat output as the original design and not as durable, is far easier to construct. Well done!

To address a couple of questions:
Linda - Plexiglas, though lighter and safer, will gradually cloud with exposure to sun, reducing the effectiveness of the heater. Clear Polycarbonate would be a better alternative. You will need legs to set your exposure angle properly and for durability. My original design had legs going back against and attached to the house. With the MEN design being constructed out of foam as opposed to wood, I would suggest you attach the bottom of the grabber solidly to the house or the ground Also, put an ice dam on the roof above it. A couple of carefully placed 1/8" holes with 8d nails inserted will lock most windows at the desired height.

Allen - Having the chambers as close to the same size as possible is ideal, though 1/8" difference (I'm guessing that's the result of not allowing for the isolator panel thickness) between the two will not have a significant effect.

I have a question: Has anyone design any type of security feature that can lock your window down when you have this in place? Maybe it's included in the Mother Earth deisng, but I missed it? If I do this, I am going to find some way to secure my window with this in place, or will be easy target for break ins.

Regarding questions on using glass, I have seen an alternate design like this that uses corrugated polycarbonate like that from SunTuff. This alternate design though was vertical an required you to cut 8" holes in your wall at top and bottom. I am going to do a "hybrid" of these two, using the materials recommended in the vertical design with the window box design of Mother's.

Here is the alternate design:

http://www.sendspace.com/file/7gkbpg

I have a question: Has anyone design any type of security feature that can lock your window down when you have this in place? Maybe it's included in the Mother Earth deisng, but I missed it? If I do this, I am going to find some way to secure my window with this in place, or will be easy target for break ins.

Regarding questions on using glass, I have seen an alternate design like this that uses corrugated polycarbonate like that from SunTuff. This alternate design though was vertical an required you to cut 8" holes in your wall at top and bottom. I am going to do a "hybrid" of these two, using the materials recommended in the vertical design with the window box design of Mother's.

Here is the alternate design:

http://www.sendspace.com/file/7gkbpg

I have a question: Has anyone design any type of security feature that can lock your window down when you have this in place? Maybe it's included in the Mother Earth deisng, but I missed it? If I do this, I am going to find some way to secure my window with this in place, or will be easy target for break ins.

Regarding questions on using glass, I have seen an alternate design like this that uses corrugated polycarbonate like that from SunTuff. This alternate design though was vertical an required you to cut 8" holes in your wall at top and bottom. I am going to do a "hybrid" of these two, using the materials recommended in the vertical design with the window box design of Mother's.

Here is the alternate design:

http://www.sendspace.com/file/7gkbpg

Apparently the Thermax insulation is getting hard to find. This article explains how to build a similar unit without using Thermax:

http://www.motherearthnews.com/Modern-Homesteading/1978-11-01/Mothers-Heat-Grabber-Is-Back.aspx?page=1

Thermax brand insulation is made by Dow. To find a distributor in your area call Dow Customer Information Group at 866-583-2583. - Mother

Can I use plexiglass instead for plan glass and still do a good job of heating

So, where does one buy thermax? I looked around online and am having a hard time finding a store that sells it or how much it costs.
Also, has someone on this board actually built this thing THEMSELVES and found it to work?

Thanks!

- Chris

So, where does one buy thermax? I looked around online and am having a hard time finding a store that sells it or how much it costs.
Also, has someone on this board actually built this thing THEMSELVES and found it to work?

Thanks!

- Chris

Wow, this gives me an idea about heating my basement some.

I think I will try this one out for myself,I used to read this mag.in the mid 70's, any chance of getting reprints of back issues?

Image Troubles

To those of you having trouble seeing the images - there's a better picture of the window mounted collector here
http://www.motherearthnews.com/Renewable-Energy/2006-02-01/Do-It-Yourself-Solar-Heat-Collectors.aspx

Plans are available to buy here if you don't mind spending $10
http://www.motherearthnews.com/shopping/detail.aspx?ItemNumber=754
Also if you click on the image gallery and go to the plan image and click on it again you can print out a fairly decent printout of the image without spending money on it

Hope this helps
BG in NC

I am gong to build this window heater asap

Hey All, you may want to check out some new technology from solarairsystems.com. I just ordered 8 Model 1536's that are a Module System that should give me about 3,800 BTU's. I purchased those plans from solarwindowheaters.com three years ago and built six units and joined them together and they worked great! Time to upgrade to a fixed system. After my research and a review of their "Patented" technology, solarairsystems.com has really peak my interest.

had anyone tried this in a cloudy climate? i live in portland, OR, where there isn't all that much sun in the winter. i need to see if its worth convincing my friend to help me build one of these :)

Wondering if we can see step by step pictures of this collector. Its very hard to image the collector just with the instructions described on Mother Earth News site. Thanks.

My house has no south-facing windows and the western side of the house is shaded by a covered porch. Will a heat grabber work well in a window that faces east?

Has anyone tried using plexiglass instead of glass? I've seen a kit you can buy at www.solarwindowheaters.com that uses plexiglass which would seem much safer. Anyone out there who has made one, do you have it resting on the ground or did you build legs under it - am wondering if this material is waterproof enough if it's sitting in snow. Also, can anyone tell me what the current cost is to build the Heat Grabber?

Is the Thermax referred to in this article the same as this Thermax http://building.dow.com/na/thermax/products/ ?

I can't wait to build the heat grabber. But the plan are not clear. Are the cold air and hot air chambers the same size in height? I appears from the plans, that the cold air chamber is 2 1/2" tall and the hot air chamber is 2 3/8" tall. Is this close enought?
Thanks.
Allan Smith

I CAN'T READ THE DETAILED DRAWINGS -- THEY ARE SMUDGED/OUT OF FOCUS ON THE SCREEN.

Bruce,

once you open the gallery and you see the blurry photos, click on the page and they will clear up. hope this helps.

Did anyone else but me notice that the image gallery is so severely blurred for this online article that it is completely useless?

Any reason why you couldn't build something like this as a free-standing unit and deliver the output through insulated tubing?

My dad's side were poor Germans living in Johnstown, PA at the turn of the century and the black boxes they built and put into the windows kept the house so warm the upstair windows had to be raised. Just 15 years ago my dad built one box for their dining roon window to show my mother free heat could be obtained. After a month my mother had him take out the box for it made the whole floor too hot. Solar heating does work.

What a blast from the past. I purchased the plans and built one of
these back then when the article came out. It really worked! I wish
I still had the plans for now I am in a new hokme with much better
south-facing windows and a very large heating bill. Jim