Basking in the sun: The case for solar heat

Relation on its head and say that a patch of full sun (at the ground) receiving 1000 W/m² corresponds to a radiant temperature of 364 K, or a blistering 91°C. This means that a black panel in full sun could get this hot if no paths other than radiation were available for cooling the panel. We would then say that the panel is in radiative equilibrium with the Sun.

But air can carry away heat by convection. The self-convection of a hot, flat plate will be about 10 W/m² per degree of difference between the panel and the surrounding air. Requiring the sum of radiative and convective losses to add up to the input power of 1000 W/m² yields a solution of about 55°C (328 K; 131°F) if the surrounding air is at 20°C. This assumes that the plate has no heat paths available through the (insulated) back side.

If, on the other hand, it is a thin panel allowing convection on both sides, it will be cooler—although the “heat rises” phenomenon will suppress heat flow on the back side relative to the front, if the plate is indeed level. Just for fun, if we get an additional 5 W/m²/K of convective loss off the back, the equilibrium temperature drops to 47°C (117°F). It all seems reasonable.

Source: GigaOm

Bucks Lake » THINGS ARE GETTING BETTER

by Mike

As I am still laid up in Reno, thanks to Kyle Felker for this information. All roads and parking lots are plowed and dry. Yipee!

The snow is reaching over a foot a day, and has become virtually anywhere drivable. However, beware of tree wells, which have become huge and very deep. As a result of sedimentation, the snow has become hard like cement and it will be hard to dig when you have to dig into your cab.

Let's look at the photo every day to see if the pot is finally working (yet), but it could happen at any time with the combination of settlement and the heater plate.Of course, there's always the possibility of damage, but we can not control that now. Kyle will go on and try to dig up the plate on Sunday, so one of these days soon, we will have a framework and a weather station.

Source: Bucks Lake » THINGS ARE GETTING BETTER