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Category: Commentary (Page 10 of 27)

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Understanding Portable Electric Heaters

It irritates me when I see manufacturers attempt to trick consumers. The majority of makers do not play this game. They present the facts, and that’s it. But, some makers do. They know that most consumers have little  understanding of engineering or physics and they try to trick people into spending $140 for something a $25 product can do exactly as well.

I’m talking about portable electric heaters. I’m talking about the makers who take out half-page full color ads that leave the impression that their heater works better than any other. Apparently, this deception must work fairly well because they can afford all those expensive ads and still make money.

A Little Background

Electric heaters are extremely simple. You don’t need a degree in engineering to understand them. In short, an electric heater uses a resistive element (a big resistor) to directly convert electrical energy into heat energy. It’s the simplest electrical product possible.

Ignoring the small losses in wiring, which are always present with any electrical product, electric heaters are 100 percent efficient. This makes them even easier to understand. All of the electricity they use is converted to heat and all of the heat goes into the space you’re trying to warm. No math required.

Conversion of Units

The next two paragraphs involve multiplication. You can skip them if you want.

We convert pints to gallons by multiplying by 8. We convert liters to quarts by multiplying by 1.057. Liters, quarts, pints, ounces, milliliters, are all measures of volume. They can be converted by one multiplication. When we can convert units by simple multiplication, scientists say they are “of the same dimension.” Inches and centimeters are of the same dimension. Tons, pounds, and grams are of the same dimension.

Electric heaters are rated in terms of their electric power consumption in watts. In the USA, we traditionally measure heating power in BTU (British Thermal Units). If we want to discuss how much actual heating results and how much the electricity will cost you for that heat, we need to talk in terms of energy, not power. To do that, we add the element of time, customarily “per hour”. So we’ll use watt-hours (Wh) and BTU per hour, or BTU/h. Watt-hours and BTU/h are both units of energy, both of the same dimension. We can convert Wh to BTU/h by multiplying by 3.412. It’s that simple. A 1000 watt heater running for one hour will produce 3412 BTU of heat energy. There’s no way to change this, no way to “improve it”, it’s hard physics.

It Makes You Say “Hmm”

Imagine two identical rooms with the same thermal characteristics (insulation) and the same starting temperatures. We put a simple, reliable 1500 watt milk house heater and a 1500 watt $140 snazzy wood-grained heater with fake fireplace in the other room. Turn them both on full power. Two hours later we measure, and both rooms will have risen to exactly the same temperature. Hmm.

Why 1500 Watts?

Electric heaters have been essentially the same since the 1920s. Nothing has changed because there is nothing to change.

In the USA, domestic portable electric heaters come in power ratings that range from 200 to 1,500 watts. 750W, 1000W, 1200W, and 1500W are the most common. Why not more than 1500? The limitation is set by typical household wiring in the USA. Standard electrical outlets in the USA are protected or “fused” (with circuit breakers) at 15 or 20 amps. Voltage is 120 volts. So, the maximum power a 15 amp circuit can deliver is 1800 watts. Maximum for a 20 amp circuit is 2400W. Heater makers standardized on 1500W maximum long ago so their heaters would operate on a 15 amp circuit, with a little bit of safely margin. The bottom line here is that 1500 watts is the maximum, which sets the maximum heat output, as described above. Fancy advertising, a simulated wood grain cabinet, or simulated fireplace flames cannot get around this limit.

Don’t fall for the scam ads that claim their electric heater heats better than others. It cannot be true without violating the laws of physics.

A Common Flaw to Be Aware Of

Many electric heaters are equipped with thermostats. If you use portable electric heaters, you’ve probably noticed that those thermostats don’t work very well. They certainly don’t work well for regulating the temperature in a room. There’s a reason for that.

For a thermostat to regulate the temperature in the room, it needs to measure the temperature of the air in the room. The thermostat is located inside the heater housing, which is warmed by the heater. This is the problem. The heater runs, the heater’s enclosure/housing warms up, the room warms up, and the thermostat turns the heater off. The room cools down but the heater itself and the thermostat inside remain warm. Even worse, many heaters have the controls and thermostat located at the top of the heater for user convenience. The top portion of the heater remains warm the longest. The room may cool down to 55 degrees Fahrenheit and the top of the heater housing is still at 70 degrees from the residual heat. You’re freezing but the heater doesn’t turn on. This problem can’t be fixed without locating the thermostat away from the heater. Locating the thermostat sensor at the bottom of the heater can help, but even the bottom of the heater is warmed by radiant heat.

What’s more, in winter, there is often the problem of “stratification”. Even though the room is warm, there can be a layer of cold air near the floor. The room might even become too warm for comfort because the thermostat sensor is in that cold layer at the floor.

The only way to fix these problems and make a portable heater work like conventional heating is to use an external thermostat.  Ideally, the thermostat sensor should be located about five feet from the floor.

Two Kinds of Electric Heaters

This difference is real. This difference has nothing to do with heat output in BTUs. It has to do with how living things like you perceive the warmth and how quickly it makes you comfortable.

The two kinds of heater are convective and radiant. When it comes to heating the air in a room, it doesn’t matter which one you use. When it comes to comfort, if you’re trying to feel warm, and warm in a hurry, there’s a big difference.

Convective heaters work by heating the air in the room directly, by contact with the air. They nearly always have fans to blow air across the heating element. They give off no light because the heating element is at a temperature of 400 to 600 degrees Fahrenheit. You turn it on and the air in the room gradually warms according to laws of physics. You can calculate what will happen and measure it. All “ceramic” heaters are of this type.

Radiant heaters emit most of their heat as infrared radiation, which warms objects in the room, including you, which then warm the air by convection. Radiant heating elements operate at temperatures from 1,000 to 2,000 degrees, Fahrenheit, so they give off light as well as heat.

If you walk into an ice-cold room and turn on a 1500 watt convective heater, it might take 20 minutes or longer to perceive warmth, and even longer to become comfortable. If you do the same with a radiant heater, it takes about 30 seconds for the heating element to warm up, and you immediately feel warm, regardless of the temperature of the air in the room. You’ve likely experienced this in front of a roaring fireplace or an outdoor campfire. In both cases, the warmth you perceive is all infrared radiation. The air might be below freezing, but if you stand by the fire, you feel good.

It would seem that radiant heat is much better. So, why are most heaters sold convection heaters? The answer is cost, ruggedness, size, and safety. Convection heaters are cheap to make, rugged, smaller, and arguably safer because they operate at lower internal temperatures. Convection heaters are more “idiot-proof” or “child-proof”.

Radiant heaters have to be physically larger in order to keep the temperatures involved at a reasonable level. Modern radiant heaters have quartz elements that are somewhat delicate. Rough handling can break them. The user has to be conscious of where the heater is located and what it’s aimed at because a radiant heater heats the objects in front of it. A radiant heater must be kept in the clear. If you place a 1,500 watt radiant heater facing a wall 12-inches away, it will blister the paint on the wall and could start a fire. Pay attention to what the heater is aimed at. On the other hand, radiant heaters are wonderful things if you use them responsibly.

In the past, radiant heaters were considerably more expensive than convection, but this has been changing recently. My favorite heater is one of these:

 

This heater is produced by a maker in China and for years was sold mostly under the Holmes brand. Years ago it sold for $190. When I bought my first one, I paid $139. Later, I bought second at $79. Today, you can get these same heaters for around $40 to $50. Chinese mass production has driven down the cost of those quartz elements. Of course, the cheaper units don’t have the Holmes name on them.

The bottom line, in my opinion, is that today there’s no reason for a thoughtful adult in a home setting to use anything other than a radiant quartz heater. Since they make you feel warmer for a given amount of electricity consumption they are more energy efficient. Cost of the heater itself is no longer an argument.

If you’re in a setting with irresponsible people, children, the elderly, animals, dirty, wet, or rugged environments, your considerations may be different. A quartz heater may not be the best choice unless it’s an industrial type, permanently mounted up high, out of reach.

The Mythical Dogma of Climate Change Denial


Some actual numbers. (Engineers like things quantified.)

Atmospheric CO2 was identified as a greenhouse gas over 100 years ago. We’ve been measuring it ever since. Technology has allowed us to measure atmospheric CO2 over ever longer time scales. Polar ice cores contain tiny air bubbles that allow us to measure atmospheric CO2 over much longer time periods. We have a clear picture of what the atmosphere has been like over the past several hundred thousand years, and longer. It’s been over 40 years since Hansen made his forecasts before Congress on what would happen in the future with respect to CO2 and climate change, and it’s all come true, and it continues to get worse. Atmospheric CO2 is now at the highest level it’s been for over a million years.

Yet, there are many people who believe that climate change is a hoax. A favorite meme that I see is that volcanoes put more CO2 into the atmosphere than humans. I was listening live when that rumor began.

In the early 90s, I enjoyed listening to Rush Limbaugh. I enjoyed his style of pretending to be highly educated and ridiculing politicians and social movements. I was listening on the day he began his long stretch of daily comments about the eruption of Mt. Pinatubo, in the Philippines. He claimed that it put more greenhouse gases into the atmosphere than humans ever have. I hadn’t considered the numbers involved carefully before so this seemed possible to me. It didn’t occur to me that a famous personality with millions of listeners would just make something up and present it as fact.

Mt. Etna, Paroxysmal Eruption

Silly me. As an engineer, I decided to look into this Mt. Pinatubo thing and see what the numbers really were. If what Rush said was true, there’s nothing we can do about global warming. It’s a natural process and we have to deal with it.

What I found shocked me. Rush’s claim was so far beyond false, so ridiculous, there are no words for it. Not only do humans utterly overwhelm the output of Mt. Pinatubo, but we overwhelm all volcanic activity on the planet combined.

The problem here is comprehending the magnitudes of numbers. There are 8 BILLION people on the planet. Most people have trouble visualizing a thousand. Then imagine a thousand thousands. Most are completely lost at this point, and we’ve only reached one million. Now take the million and imagine a thousand of those, to get to one billion. Then times seven. The Bible said to be fruitful and multiply. Well, we did that. There are 480 million tons of human flesh walking around right now.

If we gave each person on Earth a 10 by 10 foot square of land, we’d occupy 25,200 square miles. Of course, I’ve lost everyone again because few can imagine a space that big. And, we need vastly more space than that in order to grow the food we eat, process our waste, obtain fresh water, and so forth.

Our impact on the planet is far greater than anything I had imagined. We are already using nearly all of the arable land on the planet to grow our food. Yes, we fly in planes and look out over vast spaces. There’s plenty of room. Actually, there isn’t because the majority of that space is not arable land. You can’t grow food in the Rocky Mountains, or Himalayas, or in the desert, Northern Canada, or Siberia.

There are vast regions of the Pacific Ocean that are fished out, stripped down to the bare seafloor, to satisfy our need for protein. Fishing fleets scrape the seafloor itself, leaving nothing but bare sand. When astronauts look down at night, whole regions of the Pacific Ocean are lit up by vast fishing fleets.

So, eight billion people, and half of them cook over open fires. Wood averages 50 percent carbon, by weight. So a pound of wood contains 1/2 pound of carbon. When you burn that pound of wood, each carbon atom combines with two oxygen atoms to form 1.7 pounds of CO2. Burning a pound of wood results in 1.7 pounds of CO2. With 3-1/2 billion people doing this, it adds up fast.

There are more than a billion cars (a thousand millions) driving around every day, burning gasoline. Everyone must eat. We humans slaughter 800 million chickens every day. Imagine the feed and farming required just to raise 800 million chickens every day. Farming burns fuel. Fishing fleets, and a billion cars, and trucks, trains, airplanes, ships, and power generation all burn fuel. Everyone living in northern climates must heat their homes in winter by burning large amounts of some kind of fuel.

Here are the numbers. Total volcanic activity, including undersea volcanoes produces 200 million tons of CO2, annually. Human activity produces 24 billion tons of CO2, annually. It’s not even close. We humans generate 120 times as much CO2 as all the volcanic activity in the world combined. In just two weeks, we generate, as much CO2 from burning wood for cooking, as the sum of all volcanic activity in a year.

To say that one volcano in the Philippines generated more CO2 than humans have ever produced?? Wow. In one fell swoop, I saw Rush Limbaugh for what he was.

Yet Rush’s little prank caught on. Ridiculous as it is, Rush’s Pinatubo Meme is still quoted 25 years on.

Physical Security and Walls


Obvious, but not obvious.

There’s an important concept in the security field that everyone should understand. I’m writing this now because of all the discussion about building a wall at the USA/Mexico border. Some of you will find what I have to say obvious. Most will find it to be a new way of thinking that they hadn’t consciously thought about before.

Back in the last century, I spent 15 years building a company in the security business — physical security, access control, tracking of personnel within a secure facility, and asset tracking. Focus was on facilities needing the highest level of security, mostly government, so our systems supported man-traps, two-man-rule (required for access to nuclear warheads), surreptitiously weighing personnel as they entered and exited to detect systematic theft, collecting data that could indicate impaired performance of personnel, on and on. Back in the 1980s, if you visited the headquarters of the three letter agencies you passed through systems designed by me. In the 80s and 90s, Reagan, Bush, and Clinton controlled zone security the Whitehouse with my systems. FBI evidence rooms and all federal court facilities are secured by my systems today. If technicians need to work on a nuclear warhead at facilities where they are stored, their access is controlled by systems I designed. When the Soviet Union fell, the USA stepped in, and I and others worked on systems to physically secure the Russian nuclear arsenal until they put a stable government together.

When I began in this field, I was just an electronics engineer and software guy, who had done a lot of things. In the course of working in security, I was fortunate and privileged to work with the roughly half dozen guys in the USA, who are the most skilled and knowledgeable in this field. They all worked for various agencies in the government and I can’t describe how brilliant, experienced, and amazing they were. I learned a great number of fascinating and useful things. Over the years, it became clear that there are a number of basic principles that govern the field of security, like the laws of physics. One partner and I repeatedly discussed writing a book on these principles, but we never got around to it.

One of the principles or realities of physical security, the most important one to have clearly in mind, is that there’s no such thing as foolproof physical security. We constantly hear promotional phrases like “bulletproof security”, built like Fort Knox, impenetrable as a bank vault, uncrackable codes, unpickable locks, etc. There is no such thing. Any security scheme devised by Man can be defeated by Man. The only thing that security schemes do is buy you time. In the case of physical security, it buys time for humans to respond with force to an intrusion attempt. Hopefully, it raises the time cost/risk high enough that an intruder isn’t willing to try. That’s all it does. It’s a delaying mechanism and nothing more.

If there is no human to respond to an intrusion attempt, then there is no security. Security depends on human intervention and how long it takes for the response to arrive. This is obvious once you think about it. It’s just something most people don’t consciously think about. It’s not pleasant to think about because it makes you feel naked to realize that all the fancy security systems you have are worthless if an armed response doesn’t arrive in time.

Now you’re thinking about it. I hope this informs your thinking about the security measures in your home and business.

It also means that a border wall is useless without intrusion detection and armed response. Adding that to a wall costs more than the wall because it’s a perpetual ongoing expense involving lots of people. This is the drawback of all walls, including the Great Wall of China. Walls are not standalone solutions. They must be defended.  In its day, the Great Wall did its job because it was defended. Yes, the Great Wall of China was manned 24/7 from one end to the other.

There are other considerations, but there’s no need to get into them here. All arguments say that undefended walls do not work. History proves it.

$1.5 Trillion Tax Cut Fails to Deliver What Congress Promised

Time: December 2017
Place: Washington, DC

Congress: We’re going to restructure the tax code and give you corporations an enormous $1.5 trillion tax break.
Corporations: Great. Thanks.
Congress: We believe this money will cause big corporations like you to increase your capital expenditures, which will stimulate the economy.
Corporations: Why would we do that? We’ll use the money for stock buybacks that drive up the price of our stock and we’ll pocket the rest of it.
Congress: Wait. What? Well, we’re going to do it anyway because our big donors want it and Trump wants it.

Reuters: $1.5 Trillion US Tax Cut has No Major Impact on Business CAPEX.

Please comment below.

IRS Building, Washington DC

IRS Building, Washington DC

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