We use the kind that’s called “soft white” – we don’t remember the brand, but they sell “warm white” and “sunlight” and “bright white” and “soft white” and we always go for that one. Hope it helps!

xo,
s

Thanks for your expertise Melissa! Interesting and entertaining!

xo,
s (& j)

http://www.youtube.com/watch?v=Cb2kBFqrZx8

Heat won’t pass from a cooler to a hotter
You can try it if you like but you’d far better notta
Cause the cold in the cooler will get hotter as a rula
Because the hotter body’s heat will pass to the cooler

Unless you add energy to move a refrigeration cycle, which is the closest thing to a miracle science can make, and the whole reason Virginia summers are bearable. :-)

Sunlight brings lots of heat onto your house by radiation, and then it’s conducted through the walls, so the temperature differential between indoor and outdoor air is not the only factor to consider. But Dan’s simplification is valid and important to point out – it’s easier to maintain a smaller differential, which in VA means summer.

A word about heat pumps – they are a very efficient way to heat a house, because they use energy to move heat from the outside to the inside, just the opposite of an a/c or a fridge. With gas heat, you have to get the full amount of thermal energy by converting it from stored chemical energy, i.e. by burning an energy-equivalent amount of gas. With electrical resistance heaters (hot wires like some space heaters), they are 100% efficient in that all the electrical energy becomes thermal energy, but they require more total energy input. Heat pumps instead use a refrigerant to absorb heat from the outside and release it inside in a warmer space. Because this is counter to the second law of thermodynamics (heat flows from the hot thing to the cold thing), it requires energy to move the refrigerant through its cycle and thereby transfer the heat. But it’s harnessing the heat in the (cold winter) air, so it’s more efficient overall! Heat pumps only work down to maybe 20°F outside, so Virginia is about as far north as they’re reliable (and they have gas or electric-resistance backups).

For the person who asked about the thermostat – I’ve read that heat pumps perform better if the thermostat is kept at a constant temperature, while a/c and other forms of heat save energy if they’re turned down until an hour before they’re needed.

Finally about the boiling water – just for the sake of discussion – what about the change in convection? Convection is the main form of heat transfer in cooking (except pizza/conduction and broiling/radiation). A rolling boil will keep more water and vapor moving past the food, providing better convection due to (a) the marginally hotter water because it loses less heat as it passes by faster (greater temp diff = greater heat transfer) and also there will be more vapor which has higher energy than liquid water at the same temp, and (b) the speed of fluid flow which affects the coefficient of convection (a totally complicated factor in the equation that you pretty much have to empirically determine). But faster fluid flow improves heat transfer, and going from laminar flow to turbulent greatly increases the coefficient of convection – in fact that might be the biggest factor. Given all of that, as an engineer I wouldn’t bet money that a simmering-boil pot and a rolling-boil pot would cook the same over many trials. I’d like to see a controlled experiment before I’d be convinced. Actually, given the laminar/turbulent info, I’d bet a small sum on the rolling boil to win.

John and Sherry, you keep on with your more sciencey thoughtful blog posts. Who doesn’t love a little geeky discussion in with their design?

No problem… I hate it that there was any controversy at all.. seriously. I love reading your blog!

Thanks… Hopefully I’ll have an ‘almost’ job soon!

Good luck to your brother.. I have nothing but awe and respect for ‘chemies’.. too much brains for me!! Just looking at a chemistry book stresses me out!

Aw thanks Brandi! Your kind words definitely made me smile and I’m sure Almost-Doctor Dan appreciated them as well. And congrats on your almost PhD!

xo,
s

I feel so horribly about how so many of the readers have posted negative comments about very basic scientific things..temperature differentials, etc. Your brother wasn’t trying to decipher everyone’s personal heating/cooling system dilemmas.. I have to applaud you for the respectful way that you answered their posts, and I’m not sure (after the second or third response) I would have been so nice.

As for Almost-doctor Dan’s credentials.. As I, too, am almost through my PhD in physiology, I can tell you that researchers do not learn things just ‘from a bench’ point of view. That’s not what we go to school for.. yes, things are tested and designed for ‘the bench’ at times; however, the ideology and theory behind what he is testing..it is from real-life issues. This is the same in any basic science or medical science field.. You learn to test things on the bench at times, but your education isn’t limited to or directed for ‘the bench’.

There are many years worth of education in his brain…

No worries… tell your brother thanks.. Chemistry is not my subject and any tips he can give are greatly appreciated .. :)