This is Alpha, the first-born, when he was 2YO.
This is Beta, the second-born, when he was about 2YO.
This is Gamma, the third-born, when he was about 18MO.
On Heating
Dec
1
2021
Today is going to be a discussion of heating and heat transfer, in the context of what heating systems make sense for buildings
First off, let’s start with some basics. Things, in general, are either good conductors of heat or bad conductors of heat. Bad conductors are good insulators. What are some good insulators? People normally think of fiberglass insulation. A nice thick sweater is also a good insulator. There’s also that expanding foam stuff. They all have in common that they hold air. All the fluffiness is there to have a bunch of air pockets. Ideally, the best insulator would a vacuum (no air), but since that’s impractical for most things, we go with the next best thing which is air.
So air is a good insulator and therefore bad conductor of heat.
Next, let’s go with air movement.
What is windchill? I’m hoping you all know the answer already, but just for completeness I’ll say here that is it the feeling that moving air imparts to people. The faster the air moves, the lower the temperature feels. So blowing air brings a cooling effect. Nothing new there, I hope.
Now let’s combine those two principles. Let’s say, in theory, we wanted to design the worst possible system for heating a place where people are. What would we do? First, we’d start by using a bad conductor of heat as our heat-delivery medium. Right? Let’s heat up something that doesn’t hold heat well, and send that around to distribute heat. Next, we’d use something that would make things feel cooler, rather than warmer – make sure windchill is involved.
Put it all together, and you get standard forced-air systems that are in just about every house built these days.
For those of you familiar with thermodynamics, please tell me how you could make a worse system for delivering heat to make people feel warm. From both an efficiency standpoint and comfort standpoint.
The only reason it’s popular is that it is cheap to install and maintain. It can be done shoddily and people won’t notice if there’s a small leak in the ductwork.
The other thing that’s bad about it is the vents are annoying. We have one in the kitchen floor right where a chair is and I can’t always scoot the chair where I want because the leg catches on the lip of the vent.
In case you’re wondering, I’m a proponent of radiant heating. It uses water, something that conducts heat well, and it doesn’t blow on you. And it’s quiet. And you can put furniture anywhere you want, without worrying about blocking anything.
On the other hand, it does make sense to use air for cooling. You want windchill, to help you feel cooler.
But whoever does not fall down and worship shall immediately be thrown into the middle of a furnace of blazing fire.
Daniel 3:6
This little article thingy was written by Some Guy sometime around 6:42 am and has been carefully placed in the Technical category.
