Solar air heating NO south facing wall or roof - options

[J.P.M.]

Just a brief update. The panel is still pumping heat into my house. I do have my first bit of maintenance though, instead of putting my fancy controller in there I just run the fan off a power supply you plug in. While I was at work "Someone" forgot to plug it in, the insulation melted and now I have a panel that works 50% I bought some new / different insulation but haven't installed it yet. How's that for lazy?

I do now have three single pane sliding glass doors and two double pane sliding glass doors to build more heaters though. It'll be interesting to see the difference. I hope to get to all that soon.

Welcome back.

Not lazy to me. Sounds like Murphy's law as applied to self induced foulups. Folks who never made a mistake probably never did anything.

A word of caution: Depending on collector materials - mostly the non metallic parts like wood frames, etc. common to DIY efforts - repeated and lengthy exposure to warm/hot air in an air cooled collector will cause the materials to dry out. This can cause problems, particularly when a collector has been stagnating in the sun, and especially when someone then turns the fan on. Depending on materials, wood may have had its kindling temp. lowered to below the collector stagnation temp. by the drying process and combustion may occur - and made more rapid when air is forced through the collector(s) when the fan is turned on.

FWIW, that drying process took several months in my first air cooled design and it did cause combustion under some unusual circumstances. No real damage but a real eye opener for me.

A suggestion which you may already be well aware of: If you plan on more air cooled collectors, consider using the double pane units as the last ones in the flow path in either a series or parallel or combination arrangement. Reason: Double pane units lose less heat. The hottest air will be farther along the collector flow path. Put the units with the lower heat loss where the temp. is the highest --->> better efficiency.

[Spiral_72]

Yes, I read back through the replies on this topic and believe it or not I've been considering where to get reasonably priced aluminum or steel shapes to make a frame. I know a guy with a large metal brake but I'd rather not drive 200miles round trip...... so yes I have every intention of replacing the wood thanks to your recommendation. Thank you so much. The double pane idea is borderline brilliant. I'd not considered that.

At the moment I'm wondering if the 3' wide, 7' tall screen collector I'm using now has the same output as a 7' wide, 3' tall. Obvioulsy the screen will have to tilt appropriately. The collector area is the same. I can't find any instances of this idea on the internet though I'm sure they exist. I did see an aluminum roofing absorber used in this orientation, not tilted, but wider than tall. I'm figuring the total heat output would be the same, maybe not as elevated as a temp though assuming air flow is the same for both panels.

I'm working on a drawing to lay three 7' wide , 3' tall collectors on my roof, standing straight up. Two rows of three will work as well, but the rear row will be in the shade until about 11am so I'd do good to run two separate fans and duct so I don't heat then cool the air in the shaded collectors. I guess I could lay them all flat on the roof, however I don't think that'll work very well for this panel style.

Let me know what you think please.

[J.P.M.]

Since you ask:

1.) I doubt if you'll see much diff. in heat production base strictly on whether the units are horizontal or vertical. Going back to prior comments, usually, the faster the air flows through the unit(s) the more efficient the heat transfer with the same caveats about more fan/duct noise, drafts and lower outlet temps (but probably more heat at a lower temp.) and more pumping power used. There ain't no free lunch.

2.) For what sounds like your application (winter heating), laying panels horizontal will cost you. Approx. best tilt is about latitude + 10 to 20 deg. or so. Laying them horizontal will cost you big time in the winter heat production dept. Besides, you'll never get the snow off them. It'll melt, refreeze and cause problems in general.

3.) As for vertical, or other orientation for that matter, with vertical probably the most severe, wind loadings and considerations are a BIG concern. 3' X 7' anything presents a big surface to the wind. Look out for and account for wind loads. If they haven't got you yet, they will.

[Spiral_72]

Thank you for your time. I'll consider it all and plan to post pictures.

I'm dying to try some wind power too, but that'll likely go on the back burner till I get this "Easier " stuff worked out.... Besides, we do not see that much wind around here.