Solar Generation: Part Two

 More about solar power, including some basics of electriciity. There is a brief introduction to solar thermal and hybrid PV/T. 

Also watch out for my predictions on solar power.

Solar Generation: Part One

How can you generate electricity? Here is a comparison of different methods including a comparison of energy return on energy invested. Guess which is the best way to generate electricity in you house?

Windows 3.0

 More about windows. This includes thermal bridges and comparison between installation costs and running costs of windows.

Windows 2.0

More about windows.

(Warning: includes an attempt to calculate the U value of a double-glazed aluminium-framed window.)

 

Ventilation: Part Two

 More about ventilation, including mechanical ventilation with heat recovery.

Ventilation: Part One

 How to get fresh air, and why to get fresh air.

Windows

 The greatest cause of regret for house builders and home owners. Watch this for more information. Watch out for the cameo by Ted Moult. 

Air and Water: Condensation and Humidity

Whenever I talk about humidity I have a strong sense that I don't really know what I'm talking about. I think this is normal, because humidity is not at all intuitive. I know that my glasses will steam up when I come into a warm room from the cold. But what goes on within walls and buildings is complicated and strange. When predicting which way the moisture will go, I end up just assuming it will go where we don't want it!

In today's video I attempt to explain. In doing so I realised I need to say a lot more about diffusion, and probably do a whole new lesson on summer humidity. I can also talk about traditional approaches to protect buildings against condensation. 

Also I suggested that high humidity could increase the risk of spreading viruses. In fact low humidity can increase the risk of spreading viruses. 

Heating and Cooling

Here's a lesson on heating and cooling. 

More about the lesson here.

And more about air conditioners here.

How to slow Down Heat Part 2: Confounded by Compound Insulation

The sums don't quite add up for the problem we looked at earlier. The two calculations for compound insulation give a slightly different answer. 

You can see the calculations with my terrible handwriting here. Or just go straight to the video below, which is much lighter on maths. 

This is the calculation looking at parts of the wall in parallel first.  

And this is how to calculate looking at the parts of the wall in series first.  

We don't get the same answer. Here's why and what we can do about it.

How to Slow Down Heat

 Now that we know it's impossible to stop heat, let's see if we can slow it down!

More about the lesson here.

How to Stop Heat

 

Watch this video lesson to find out! 

Spoiler alert: it's impossible to stop heat! You can only slow it down. If you want to lose less heat from your house, then the first thing to think about may be the surface area.

Warning: Contains equations.

What is Energy?

 The first lesson. If you want a low energy building, this is the first question you need to ask. 

What is energy? How do you measure it? I thought of a dozen different ways. This shows how confused our language is over the science. 

In politics, language is power, but when it comes to science, power has a different and much more precise meaning. Heat seems like it's hot, but often it's not. In the next video, after explaining that heat and temperature are not the same thing, I described a difference in temperature as a difference in heat. In this video I used the word "precise" when I meant "accurate". I did this while I was talking about the difference between precision and accuracy. Maybe it's not the language that's confused. Maybe it's just me!

Anyway, this has nothing to do with the content of this video. You can read more about the lesson here. 

Please watch the video, and subscribe to the channel. 

Welcome to the course

University classes are online this year, so I've started putting the low energy building course into video. Here is the first, introductory message. (Warning: contains equations!)

Please subscribe to my YouTube channel here.

If you're interested in teaching materials from my English language classes, you can also visit my other youtube channel.