Solar cooking, basic supplies, heat retention/absorption pt2

[lenhoj85]

what is family $?

[STARFIRESOLAR]

Flat black paint absorbs more heat than high gloss paint. The idea of storing heat in the botom plate for use when the cloud passes over sounds good but in actuallity it would be better to reflect or transfer all the heat onto the food pan and let the food store the heat. Also direct contact is the best method of heat transfer. Sitting the food pan directly on the bottom pan will transfer more heat than having the air space between them. Remember, the pan underneath is mostly shaded anyway.

[solarcookingnut]

though the pan underneath is shaded, you need to understand, it still absorbs heat from the heat circulating around it.

For me, using these in panel cookers helped keep the food still cooking when clouds went over. I live in an area of higher humidity, not dry. in dry areas you don't need alot of help, higher humidity, you do. what doesn't work for one solar cooker in one area, works great for another in a different area. humidity can rob a solar oven.

[solarcookingnut]

This is not true. I have put solar cookers and ovens side by side together, trying both with and without racks. the same identical pans of breads, cakes, etc when checked, the one that had no rack, the middle of the dough was uncooked while the same one on a rack, was cooked all the way through in the middle at the same amount of time. the box indeed robs the food of heat when pan is sitting directly on the floor and takes food longer to cook. this has been my experience.

[solarcookingnut]

I wasn't promoting high gloss paint. Never have. In my other videos I am clear about flat black non toxic paint. The dishes just happen to be glossy because that was what I found and had to use. And though they are glossy, as a cooking vessel, they still do a great job cooking foods. may use black enamel pans, they are glossy, and still work. Black is the key in absorbing heat. Flat indeed is better, and i state that in other videos.

[solarcookingnut]

Do this experiment, in one panel cooker, put a vessel in a bag, and set directly on the panel cooker on a partly cloudy day. beside, using the EXACT pan, EXACT food, like a cake especially, and put the set up I have with a thick black plate with a rack on it, then set the vessel on the rack. After 30 of cooking, especially with some clouds rolling over, open each bag, and tell me if the black plate is still giving off heat enough to keep temps up, ...continued in next comment....

[solarcookingnut]

continuing from previous post....Now, the one without the rack, tell me how much heat is radiating from the shiney cardboard bottom to the pan. You will find, when the clouds go over, you WILL feel the difference that plate will make.

cardboard and foil DON'T keep the food cooking at a steady rate, but the black plate will. YES, hot food does keep cooking, but heat rapidly begins to be lost if you don't keep some kind of heat source below to keep it steady until the sun hits again.

[STARFIRESOLAR]

I understand about the other pans holding heat and keeping the cooker warm inside durring clouds, I am not disputing that at all. I'm saying that there is approx. 1500 BTU per sq.ft. of area exposed. That's all you can get out of it. Efficiency is key. Concentrate the energy and cook faster, or cook slower and store some of the heat in tiles, steel, plates, etc. for cloudy or overcast times. Yes hot air under the pan will heat it more than direct contact with a poor conductor that's shaded

[STARFIRESOLAR]

I liked your videos and I wasn't trying to be a pain in the butt, I was just making comments I thought would help.

In as much as tiles and plate steel absorb heat they are not good conductors of heat as say copper or aluminum. Which may be the reason that when you have the pan sitting right on the tiles without the air space the heat is not conducted to the pan as good as it could be. In not being good conductors of heat the tiles, steel plate, and even a regular plate that is (cont.)

[STARFIRESOLAR]

is painted black, these materials do not give off (transfer) heat to the air efficiently. That's why I mentioned that if you increase the area of tiles and/or steel inside the box it would increase your heat. As I said before, when you place the pot or pan over the tiles or steel it shades it. If it's shaded it is not absorbing as much heat therefore can not release as much heat.

[STARFIRESOLAR]

There are 3 ways of heat transfer.

1 - Convection. Air is heated and rises up, cooler air falls downward. Imagine that you have a stove burner on high and it's red hot. If you hold your hand over the burner you feel the hot air rising off the burner. That is convection heat transfer.

2 - Radiation. The heat you feel that comes off a heat source without being over the heat scorce. Now imagine you hold you hand to the side of the burner. You feel the heat that eminates outward.

[STARFIRESOLAR]

3 - Direct Contact. Direct contact is the best way to conduct heat bar none. Imagine now that you put your hand directly onto the burner. That is direct contact heat transfer and It doesn't take much time to realize that direct contact heat transfer is the fastest and most efficient way to transfer heat.

[solarcookingnut]

Like I said again, you need to see my other videos. i put tiles in my ovens and show others how it helps in heat retention and keeping the temps steady in my box ovens. Place your hand on a hot plate in one of my ovens where a pan and rack was on top, and try holding on there for more than 5 seconds, I will guarantee, you will be crying and pullin that hand back and droppin that plate you think wasn't really all that hot cause its shaded by the pot :)

[solarcookingnut]

The problem is, your comments are counter productive to answering those who are struggling to cook in their ovens and cookers. All that I have been teaching here has helped many to increase their temps in their ovens, not to mention help them to cook on days where clouds roll in. I post what I know from MY OWN personal experiences with high humidity. if you done these things and failed, then it just won't work for you.

I m here to teach people to be successful, I know what works 4 me

[solarcookingnut]

I am not a technical person. I teach basics that are elementary enough for children to do understand. Some people just use one kind of oven. I don't. I use several different kinds, and able to answer alot of questions from various cookers who have issues because they are beginners. I have taught enough folks out there and helped them with these issues. If it doesn't work for you, that's ok, but it does work for me and others and its my job to get the info out there.

thank you

[sillygirl722]

I want to make a solar cooker and I would never have known this set up with the dishes and racks/tiles ect..and the heat absorption. I just wanted to say thanks for sharing this and all your other videos!! I learned more by watching your videos than the others i have seen. You explain things so well!! THANKS!!

[achsofromm]

All good points. I believe we are about to see some nanotechnology materials that increase heat production and retention. Kopin Corporation, for example, that makes displays for cell phones, just got a grant from NASA to try and improve solar conversion to electricity. If this is possible, additional heat will be an added possible benefit. Maybe we'll even be doing solar cooking on cloudy days!

[solarcookingnut]

I seen videos on the nantechnology, really something to see! I have been wanting to rig up a simple light fixture in my biggest oven to put a high wattage light bulb in to continue the cooking when there would be cloud cover. Its hard to find the ceramic light fixtures anymore, they are mostly a plastic which I wouldn't want, the heat might make it melt.

[THREEFLOORSDOWN1]

great vids! if it wasn't for watchin some of your vids, ida totally overlooked some of that & mighta failed misserably when i made mine. but then again, if it wasn't for a member on a forum posting them, ida never really thought of making one

ya, my cast iron has been working great at holding the heat! my lil sand trick wasn't 1/2 bad either.

[solarcookingnut]

Thanks! I stumbled upon it by accident myself while doing some research on solar heating, and come across a website about solar ovens, from that point on, I was totally sold! You have been doing great with your oven, and with every success you have, you will find you will keep doing this as part of everyday living. And, you can teach others as you keep gaining more knowledge.

Looking forward to the next meal you cook and posting it!

[THREEFLOORSDOWN1]

i've cooked a few more since my meatloaf vid, but they were the same things id already filmed. i was gonna try a roast on sunday,but the rain didn't hold out

[solarcookingnut]

yeah, rain has been a problem here too. But I was able to cook some steaks and brown rice the other day, REALLY GOOD! Then made some solar brownies, left them in to make them crunchy! Poured the batter into a large pan to spread it thin. Had to hide them from both of us, lol.

I will be posting a video about heat retention cooking for those days when it starts to cook but clouds roll in. Stay tuned!

[lunayahwitch]

I just love your videos! I was curious if your solar cooking knowledge is from a specific source or is it from years of trial and error? I homeschool my daughter in vermont and we really want to do some activities based on solar energy, specifically cooking. You're videos have been such a good resource for me so I have a better idea of what to do. Hopefully it will be something we do all the time. Keep up the videos, we love them all!