Things You Don't Want To Hear

Today was an extremely windy day, with wind gusts up to 60 miles an hour. The building I work in is only a four story structure that is wider than it is tall, and I'm on the top floor.

After a particularly strong and sustained gust I turned to my coworker and asked, "Is it me, or is the building swaying? I think I felt my desk move."

He said, "It's not you."

Yikes.

Hot And Busted

No, it's not the name of a new supermodel reality show-- it's the air conditioning: hot and busted.

Of course these things only break when you use them - which, of course, is precisely when you need them. It's been hot, humid, and generally miserable all week. It is 90-100F during the day and it "cools off" to 80 at night.

To a mechanical ignoramus like me, I know one thing: it's busted. Other more enlightened souls may care about how this magic box called the Air Conditioner (AC) works.

From How Stuff Works:

Air-conditioning Basics

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Most people think that air conditioners lower the temperature in their homes simply by pumping cool air in. What's really happening is the warm air from your house is being removed and cycled back in as cooler air. This cycle continues until your thermostat reaches the desired temperature.

An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant, like Freon, to provide cooling. The mechanics of the Freon evaporation cycle are the same in a refrigerator as in an air conditioner. According to the Merriam-Webster Dictionary Online, the term Freon is generically "used for any of various nonflammable fluorocarbons used as refrigerants and as propellants for aerosols."

Diagram of a typical air conditioner.

This is how the evaporation cycle in an air conditioner works (See How Refrigerators Work for complete details on this cycle):

1. The compressor compresses cool Freon gas, causing it to become hot, high-pressure Freon gas (red in the diagram above).
2. This hot gas runs through a set of coils so it can dissipate its heat, and it condenses into a liquid.
3. The Freon liquid runs through an expansion valve, and in the process it evaporates to become cold, low-pressure Freon gas (light blue in the diagram above).
4. This cold gas runs through a set of coils that allow the gas to absorb heat and cool down the air inside the building.

Mixed in with the Freon is a small amount of lightweight oil. This oil lubricates the compressor.

Air conditioners help clean your home's air as well. Most indoor units have filters that catch dust, pollen, mold spores and other allergens as well as smoke and everyday dirt found in the air. Most air conditioners also function as dehumidifiers. They take excess water from the air and use it to help cool the unit before getting rid of the water through a hose to the outside. Other units use the condensed moisture to improve efficiency by routing the cooled water back into the system to be reused.

So this is the general concept involved in air conditioning. In the next section, we'll take a look at window and split-system units.

Window and Split-system AC Units

A window air conditioner unit implements a complete air conditioner in a small space. The units are made small enough to fit into a standard window frame. You close the window down on the unit, plug it in and turn it on to get cool air. If you take the cover off of an unplugged window unit, you'll find that it contains:

• A compressor
• An expansion valve
• A hot coil (on the outside)
• A chilled coil (on the inside)
• Two fans
• A control unit

The fans blow air over the coils to improve their ability to dissipate heat (to the outside air) and cold (to the room being cooled).

When you get into larger air-conditioning applications, its time to start looking at split-system units. A split-system air conditioner splits the hot side from the cold side of the system, as in the diagram below.

The cold side, consisting of the expansion valve and the cold coil, is generally placed into a furnace or some other air handler. The air handler blows air through the coil and routes the air throughout the building using a series of ducts. The hot side, known as the condensing unit, lives outside the building.

The unit consists of a long, spiral coil shaped like a cylinder. Inside the coil is a fan, to blow air through the coil, along with a weather-resistant compressor and some control logic. This approach has evolved over the years because it's low-cost, and also because it normally results in reduced noise inside the house (at the expense of increased noise outside the house). Other than the fact that the hot and cold sides are split apart and the capacity is higher (making the coils and compressor larger), there's no difference between a split-system and a window air conditioner.

In warehouses, large business offices, malls, big department stores and other sizeable buildings, the condensing unit normally lives on the roof and can be quite massive. Alternatively, there may be many smaller units on the roof, each attached inside to a small air handler that cools a specific zone in the building.

Hail, Hail

Last Friday evening we got nailed by a sudden hail storm. I had just finished saying, "I think I'm going to till the garden before it gets too late", when the skies darkened and 1"-2" hail started coming down in a deluge.

It was so violent, we decided we had better close the drapes in case the windows broke. We looked out onto the lawn and the hail was getting such a good bounce it appeared that hail was jumping upward from the grass by six inches.

Somebody (not me) got some video of the storm.

When it was all over, it looked like someone had opened dozens of bags of party ice all over. The hail melted fairly quickly after all was said and done which created a fog over the streets.



Wild stuff.

Tales From The Cold: Aftershock

The DC region still hasn't really recovered from the blizzard of 2010. We don't get snow measured in feet here normally, and we don't deal with it well regardless of amount.

For whatever reason, the traffic this morning was abysmal and there was nowhere to park at the Metro garage as half the top deck still has ice mounds on it. I parked a mile away at a shopping center and hoofed it back to the train nearly getting myself run over in the process since the sidewalks are unavailable.

The blizzard was a lot like an earthquake for our region. Like most large earthquakes, there are always aftershocks. Now there is more snow in the forecast. (Rumble, rumble) It's only 3 inches this time; normally that would be paralyzing for us, but after the blizzard nobody is panicked over it. It's all what you're accustomed to, I guess.

In Deep

It's still snowing like the Dickens out there. Last time we got plastered was ... well two weeks ago. But before that, we haven't seen this much snow since 2003.


I've done a couple of passes on the driveway at two hour intervals and we had 2-3 inches each time. Mrs. Nod is taking a turn and she's got 3-4 inches to push around. So we've already cleared upwards of 10 inches and we have 10-20 more that will drop overnight. It's really coming down at a good clip. Mrs. Nod just finished and there is already another quarter inch on the driveway.

Wheeee! Snow, snow everywhere!

Salute To The Shopping Cart

You don't know how much you miss it until you can't find one in a snowstorm. By that we mean a shopping cart, of course.

Tonight there was not a spare shopping cart to be found. Every single one was in use and the store was full. Lines all the way to the back of the store.

On the day before we get socked in by 1-2 feet of snow everybody heads to the grocery store to get milk, bread, and toilet paper. Heck, if we were going to get 1-2 inches that would happen.

Now it's bunker mentality: they actually said prepare yourself to be homebound for up to 5 days. Really? Come on! Even the blizzard of '87 wasn't that bad. People just walked to the store. Sure, it was inconvenient, but you didn't need a shopping cart because you couldn't carry that much home.

If I were to stock up for being home for 5 days the way that these people were doing tonight, it would look like I was preparing for Armageddon. Even my "quick trips for a few items" to the grocery store involve a lot of stuff. That's just how it is when you've got 7 mouths to feed. Even in good weather I'd be buying 3-4 gallons of milk at a whack. People always assume I'm buying for a party; in a way it is, if you consider living in a big family a party. Boom. Instant party; just add Nods. Our regular family brunch is bigger than most kids' birthday parties.

The shopping cart is my friend. It lets me know when it's time to stop buying things, because nothing else will fit in my overflowing basket. Ah. Here's one now. Let the games begin.

Weather In Parts Yonder

Since we're about to get blasted with our second two-foot snowfall in as many months, I thought it might be good to check out the weather in other parts ...

Getting Dicey

Here is the weather forecast for the DC Metro area for this weekend: BIG SNOW. People around here don't exactly drive well in any amount of snow, never mind 20 inches. Already there is an inch on the ground, with lots more to come.

Part of the problem as Mrs. Nod pointed out is that the temperature frequently hovers around freezing -- which means sometimes above and sometimes below. This leads to melt and re-freeze (better known as ice) -- and no one drives well in ice: it's a physics thing. Got 4-wheel drive? Great. Got 4-wheel stop? Didn't think so.

In addition to snow, we get varying amounts of sleet, hail, freezing rain, freezing fog (really!), and sundry mixed precipitation. Conditions are constantly changing, roads are not exactly straight and level, and there is a high transient population who have never seen snow.

You might not be afraid of snow driving, but you'd better be afraid of that other idiot on the road.

WINTER STORM WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM EST SUNDAY...

A WINTER STORM WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM EST SUNDAY.

* PRECIPITATION TYPE... SNOW.

* ACCUMULATIONS... HEAVY SNOW WITH ACCUMULATIONS OF 10 TO 20 INCHES THROUGH SATURDAY NIGHT.

* TIMING... SNOW WILL BEGIN BETWEEN 11 PM AND 2 AM TONIGHT AND WILL CONTINUE THROUGH EARLY SUNDAY MORNING. SNOW WILL BE HEAVIEST BETWEEN 8 AM AND 6 PM SATURDAY.

* TEMPERATURES... UPPER 20S TO LOWER 30S THROUGH THE EVENT... LOW TO MID 30S IN COASTAL SOUTHERN MARYLAND.

* WINDS... 10 TO 20 MPH THROUGH THE EVENT... WITH GUSTS OF 25 TO 30 MPH SATURDAY AND SUNDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A WINTER STORM WARNING MEANS SIGNIFICANT AMOUNTS OF SNOW ARE EXPECTED OR OCCURRING. STRONG WINDS ARE ALSO POSSIBLE. CONDITIONS WILL DETERIORATE VERY RAPIDLY SATURDAY MORNING AND WILL MAKE TRAVEL EXTREMELY TREACHEROUS.

Fogged In

First snow, then rain, now freezing fog. The weather outside is "frightful". This picture shows the fog has socked in the American Legion bridge even as late as 9:00am.

Friday's Been Canceled

You just don't know what tomorrow will bring.

According to the BBC, global warming has been canceled and global cooling will take its place. Carbon credit junkies would prefer if you'd just call it by its generic name, climate change.

Banks everywhere are canceling people's credit cards and loans have dried up due to the global recession, even for people with good credit.

Joanie Loves Chachi has been canceled for decades, but nobody really noticed.


But to top it all off, according to the weather channel, Friday's been canceled as well. It doesn't matter -- apparently it was going to rain anyway.

Weather Bound For DC Keeps Kids Homebound

Here comes Snow in Washington, D.C. It's supposed to be the big one for us -- up to 8 inches. While it's no northern blizzard, it's pretty much paralyzing for this former swamp area.

The residents are highly transient, with most people coming from somewhere else, and so snow experience varies accordingly.

Just as it only takes a few "bad seeds" to ruin a neighborhood, it only takes a few "bad drivers" to make driving in the D.C. metro area a nightmare.

Add to this the fact that Virginia never planned its roads for cars, they just paved the cow paths, and it's doubly dangerous.



Finally, every yuppie in an SUV around here thinks they can "drive in the snow because they have 4 wheel drive". Hey, genius, no one has 4 wheel stop!

It may be a good day to stay home.