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Ever wonder how your bathroom fan contributes to the heating and cooling efficiency of your house? You really should consider it.

If the bathroom were air-tight, that would create quite a vacuum. But bathrooms are not that air-tight. So for the air that leaves the bathroom, the same amount of air is going to enter the bathroom, to replace the old air.

Where does that new air come from?

In most houses, it comes from all over – various leaks throughout the house: doors, windows, pipes and vents through walls.

So air goes out of the bathroom, the bathroom gets new air from the rest of the house, and the rest of the house gets new air from outside – through cracks and leaks in doors, windows, the foundation, etc.

Like this:

In places like the Midwest, you don’t want outside air inside the house. Air conditioning has made the inside air cool and dry, in contrast to the outside air which is hot and humid. So having the bathroom fan draw outside air into the whole house is a bad plan.

Once you’re done in the bathroom, the air conditioner has to condition the replacement air. And that air is spread throughout the house.

If you have a make-up air unit in the bathroom, though, the replacement air comes from the outside straight into the bathroom. So now the volume of replacement air is confined to one room. So most of the house stays comfortable, and the air conditioner has less work to do.

Like this:

One of the projects I would do in a house where I planned on living for a while is to add an HRV to each full bath and to the kitchen. An HRV is a Heat Recovery Ventilator – it brings in replacement air and conditions it slightly. They are needed where there are exhaust fans – bathrooms and kitchens if the kitchen has a vented range fan.

Some people may argue that you should have just one HRV and make it large enough for the air needs of the whole house. But I’d rather have multiple smaller HRVs on principle.

Now for some numbers, in case those previous paragraphs were not interesting enough:

We’ll take an average of 80 CFM for a bathroom fan. Our bathroom is about 6x10x8, so 480 cubic feet. That would mean a roomful of air gets removed every 6 minutes.

I will assume an average shower is 10 minutes, and to make the math easier I’m going to assume the fan is on for a minute before and a minute after the shower, for a total of 12 minutes of bathroom fan run time.

So for the 960 CF of air that leave the bathroom, 960 CF of air are going to enter the bathroom, to replace the old air.

If the air comes from wherever, it is going to be 960 CF of air throughout the house. But if draws new air through the bathroom only, it is going to be only 480 CF. The first 480 CF will be outside air replacing conditioned air, but once the bathroom has exchanged all its air, any more air that comes through is going to be outside air replacing outside air, so no more conditioned air gets lost.

For his next labor, Hercules had to clear his inbox. His nemesis for this task was the Thuerkian Hydra.

The Hydra was a serpent-like beast with many email addresses. Each address could carry an attachment venomous enough to make the recipient wish he could unsee it.

The Hydra lived in a cave near the swamps of Thuerk. The cave was also where the springs of Anonymous originated. From time to time the Hydra would leave the swampland and raid nearby villages, greatly complicating life for the peasants who lived there.

Hercules, travelling with Iolas, arrived near the cave. Arranging cloth over his eyes to protect himself from Hydra’s venom, he send a number of hostile and insulting messages to the Hydra, mainly disagreeing with the Hydra’s views on a variety of subjects.

This caused the Hydra to emerge from the cave, enraged. Unwanted email after unwanted email viciously attacked Hercules. He wielded his mouse deftly, clicking on Unsubscribe before the images had a chance to load. But for each email he unsubscribed, two more email addresses started sending him messages.

This was a losing battle for Hercules. He could not escape, he was getting tired, and the beast was growing.

Desperate, Hercules called to Iolas for help. Grabbing a keyboard, Iolas told Hercules to click Reply instead of Unsubscribe. To each message that Hercules Replied, Iolas added a 550 Invalid Recipient header. This prevented new addresses from growing.

Finally, the Hydra was down to its one immortal address. Hercules was able to, with his great strength, unplug that server and bury it under a great boulder from which it could never escape.

The End.

We have a DVD with some music on it. I wanted to be able to play the music in our vehicles and various other places that don’t play DVDs – a valid case of the fair-use doctrine, if you ask me.

I figured it should be straightforward – the laptop can play DVDs, and the laptop can burn CDs, therefore the laptop should be able to take the audio part of the DVD and save it off.

But it’s not that easy.

The DVD player won’t save audio.

And when I tried just using either Sound Recorder or Audacity to record the audio as I played the DVD, but it came out warbly. Like it was underwater or something.

So I figured someone out there has written a utility that would grab the audio from a DVD and save it as a standard audio file.
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Disclaimer: if you haven’t seen The Matrix, you might not fully appreciate this blog post. Remember to watch only the first movie.

How did the people progress from how we are now to how they were in the movie The Matrix?

Simple: gradually.

You start with nothing – content and complete by yourself.

Then you add in an audio connection to devices – iPod.
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In the interest of combining things (“leveraging technology” if you want the appropriate buzzwords), I thought through how wind turbines could sell advertisements.

By “wind turbines” I am referring to the tall, 3-vaned, modern-looking windmills that generate electricity (and kill birds) and are popping up in more and more places.

In fact, my niece plays soccer in the shadows of a few of these.

Now for the advertisements. If you’re not familiar with the concept of Persistence of Vision, here’s an example:

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I’m not sure what to think about security questions. You know, the things they make you answer when you forget your password.

There are some times when I wonder “why not do away with the password?” If answering a couple security questions is good enough to get a new password, then mabe it’s good enough to replace a password.

And some times I get asked a security question I don’t remember setting up, and there are multiple possible answers. In that case, what’s the fallback if I can’t get the answer right?

After seeing a few too many security questions to which I answered (in my head) “How am I supposed to know that?”, I was inspired to come up with a list of bad security questions.

For those developing login sequences, here are questions that will annoy your users:

• Who sat next to you in 3rd grade?
• What was your favorite baby food?
• How old were you when you got your first tooth?
• What country were your great-grandparents born in?
• What was your favorite color in 5th grade?
• How many second cousins do you have?
• How old were you when you lost your first tooth?
• What is your favorite noble metal?
• How long was your bus ride in middle school?

All of those are things which are ambiguous or I don’t know or they don’t have an answer.

Any other examples of bad security questions?

There once was an IT manager who tended the computers at a business on the outskirts of town. He was bored, because things were running just fine.

To amuse himself, he sent out a company-wide email that said “Critical Security Issue: all employees must change their passwords immediately. Every password must be at least 8 characters long and contain at least one uppercase letter, one lowercase letter, and one number.”

The employees scrambled to comply with the new directive. To those who asked if it was critical because passwords had been stolen or compromised, he replied with a laugh, “It is in keeping with industry best practice!”

“Don’t cry ‘critical security issue’ if it’s not critical,” the employees said as they slammed the door behind them.

The next week, the IT manager was bored again.

To amuse himself, he sent out a company-wide email that said “Critical Security Issue: All employees must use Internet Explorer only. Any other browsers (Firefox, Chrome, and others) will be automatically uninstalled.”

The employees scrambled to comply with the new directive, and to understand it. To those who asked if it was critical, he replied with a laugh, “It’s in the best interest of the corporate network to reduce security holes.”

“Don’t cry ‘critical security issue’ if it’s not critical,” the employees said as they slammed the door behind them. “And why choose IE as the preferred, no – required, browser if the goal is to reduce security flaws?” they employees wondered, to no avail.

The next week, someone outside the company had posted financial documents that were not yet published, and the IT manager could see there was a lot of unusual network activity occurring.

The IT sent out an urgent company-wide email that said “Critical Security Issue: All employees must disconnect their computers from the network due to a security breach.”

The employees didn’t even see the email, since they had all setup a filtering rule in their email software so that anything from the IT manager went straight into the virtual trash can.

The IT manager noticed there was no effect on the network activity, so he shut down the servers and took everyone offline. The employees, being the resourceful creatures that they were, enabled their phones’ internet sharing capabilities and worked off that, or left for a coffee shop, or went home and worked remotely – all the while keeping their work laptops connected to the internet. The IT manager sat helplessly as all the company secrets flowed into the public.

The next day, the big shots called the IT manager into their offices, wanting to know why all their files were gone.
“Didn’t you read my email about logging off yesterday?”
“No, your emails full of sound and fury, signifying nothing.”
“But that one yesterday was important.”
“Corporate policy states that email communication must be professional and accurate. Labeling everything as ‘critical security issue’ doesn’t strike us as accurate.”

Since the company had to spend a lot of money on the subsequent damage control and lawyers, it didn’t have enough room in the budget for the IT manager. He was laid off, but eventually found a job as a headline writer for a major news outlet.

The End.