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Tag: tutorial

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 1500 watt milk house heater like this one 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 like this one.  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 even start a fire. It’s not idiot-proof. On the other hand, radiant heaters are wonderful things if you use them responsibly.

In the past, radiant heaters have been 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 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.

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.

RSS Simplified For Users

What is RSS and how can it help me? Blogging is on the rise again so this question comes up often today. The easiest way to answer it is to understand why RSS was invented. So here’s a quick overview, skipping lots of details you don’t need to know to use RSS.

Back in the 1990s, I’d begin a session online by visiting the Yahoo news page. Then I’d pull up the Yahoo business page, then Reuters, then the BBC. Then I’d check on the forum I ran and another forum run by a friend. Then I’d check the Usenet groups I followed. All of this was done by manually clicking on bookmarks, waiting for the page to load, and navigating up and down pages. Internet connections were much slower then and page loads were often slow. What’s more, if nothing had changed on that web site, I just wasted my time loading it. During the day, I was busy. I’d check back on some sites, but not all, so I would miss things.

All this clicking and waiting was tedious and annoying, so a better way was invented. There were a couple of false starts, then RSS was born around 1999 or 2000.

The idea behind RSS is for a web server, upon request, to deliver a “hidden” web page that contains a summary of content in a precise format. RSS defines the format. The file is encoded in XML so it’s easily decoded by a computer. This file is called the “RSS feed”.

Web designers decide what information is provided in the feed. It contains, at least, things like article titles, dates, and a snippet of each article’s text. It can include much more as the web designer wishes.

With the RSS standard in place, it became possible to create RSS Reader software. To use a reader, you configure it with the RSS feed addresses of all the web sites, blogs, and forums you want to stay on top of. From then on, the RSS reader updates itself automatically and shows you the latest stuff from all your sites, gathered together in one place. There are many RSS readers to choose from that will display information in a way that pleases you. No more manual surfing to a dozen different sites or wasting your time on sites that haven’t changed. RSS Readers keep track of which articles you’ve read and lots more. For instance, most readers can be programmed to alert you if certain key words are detected. This can be extremely useful.

Any web page that’s equipped to deliver an RSS feed will either have a link that says “RSS” or an icon that looks like this.

RSS Icon

If you click on that link, you’ll get a page of “gibberish”. That’s the gibberish your reader wants to see. If you’re curious, take a look at it. XML is text designed to be readable by machines and humans.

What you actually want to do is right click on the link or icon and select “Copy Link Address”. Then paste the link into your reader software. Your reader will explain how to do it. Usually there’s “add site”, or “add source”, or a plus sign to add another feed. That’s all there is to it. Since blogs have a low rate of change, it’s reasonable to follow hundreds of blogs and not be overwhelmed with information.

I hope this helps. Happy Blogging!


RSS Reader Solutions to Consider

It was suggested to put some recommendations here. I think it’s a good idea. However, to be honest, I haven’t tried lots of readers, so I’ll have to do some research. There’s a wide range of readers out there. Some are very simple and run from a command line. Others are big and loaded with features. There are also web-based readers. All recommendations are welcome. Please comment below about any readers you like or dislike, and why.

Years ago, this would have been easy: use Google Reader. Done. Google Reader was an excellent, very cool product, but they killed it. So, nevermind that.

EDIT: I’ve deleted what was written here before because I still don’t have a solution that I like for myself, and some of the info I presented was false.

Specifically, I was using Liferea on Linux. I like it a lot. I’m fairly picky about how a reader UI is layed out and Liferea was perfect. Liferea also supports podcasts. It’s considered the best reader for Linux by many. Every article that mentions Liferea says it supports various sync protocols like Tiny RSS, The Old Reader, etc. and Inoreader, and has since 2012. So, I beat my head against the wall, trying to get Liferea connected to my Inoreader account. Nothing worked.

Then I found some release notes from September 2018 and buried there was a little note: “Inoreader support removed. API broken.”  !?   Thanks a lot.

So, back to square one.

NOTE: This doesn’t have to be as complicated as I’m making it. There are dozens of readers that work fine and provide easy solutions. For example, you could set up with Feedly on your web browser (feedly.com) and be up and running immediately. For Android there’s a Feedly app. Problem solved. This may be the best way for a beginner to get started. Or, you could use the browser-based Inoreader (inoreader.com) and install the Inoreader app on your phone. Boom, solved.

In my case, I’m very picky. I want to use a native reader on my laptop, not a browser reader, and have it sync with an Android app on my phone. I want a reader with a certain layout that is largely text based, not graphical. I want podcast support. I could even set up my own server to provide the sync service.  This becomes complicated because I’m picky. So, don’t use me as an example. This is easy to set up if you’re not so picky.

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