Air Tech

Clean Your Coils

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Most people think that it’s only the filters that get dirty. That’s almost right. Almost. Your filters are going to be the first thing you notice being incredibly gross, but the entire HVAC system is exposed to the same types of dirt, pollen, and mold. These can sometimes get past the filter, but that’s not where the biggest problems lay. Efficiency The key parts to your HVAC system are often radiators of some sort (depending on the type of system). If you have hot water heat, you probably have baseboards, which are essentially radiators. Your air conditioner has two radiators, a condenser and an evaporator (these usually called Coils). The job of these devices is to move heat from one place to another. In some places we take heat from the air and put it into a refrigerant. in other cases we take it from the refrigerant and put it in the air. When these things are designed, engineers use materials that are known to have incredible thermal conduction capabilities. We know that paper is an awful thermal conductor and that metals tend to be amazing conductors. Beyond that, we know that specific metals are better conductors than others, conduct into the air better, and we know the number of fins and distance between them necessary to get amazing performance. Under ideal circumstances, especially when these products are fresh and new, they will work flawlessly. When the coils are all […]

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Building Controls

Grading Your Steam

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As with all things scientific and industrial, there are ways to quantify just how good steam is and where it can be used. We can think of these as three basic grades of steam: Utility, Culinary, and Pure. These essentially deal with how sterile the steam has to be, how much or how little water vapor it can carry, and what contaminants or additives it can be exposed to. Utility Steam There are numerous applications where the chemical make up of the steam isn’t a terribly big deal. Consider steam used for heating oil pipes. It doesn’t matter if the steam is wet or dry, if it contains any anti-corrosives, or if we put anti-freeze in it to prevent pipe bursts in the return lines. This is steam that’s never going to come into contact with humans, never touch food or clothes, or otherwise be an exposure risk. We put up a nice biohazard sign, some skulls and crossbones on the pipes, a sign that reads “if you drink, touch, or breath this, not only will you die, but it will be slow and painful,” and everything is pretty much set. The same can be said for steam used exclusively used to heat a building or dedicated to other purposes. In these environments, there’s not going to be human exposure, so it’s treated like any other chemical. In these instances, it’s helpful to use additives to extend the life of […]

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Building Controls

Industrial Wet Steam

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Let’s recap quick: wet steam is the steam you usually see around your house and basically everywhere not investing seven to eight figure checks in their steam system. This wet-steam carries water vapor, which is the actual white, puffy cloud you see. Dry steam is essentially invisible, hot as fire, and essential in industrial scale productions. That begs the question though, is there an industry for wet steam too? Surely the dry-stuff is better? Moisturizing the Product It turns out, there are a ton of applications where it’s essential to add moisture to a product without actually soaking it. Consider, if you use dry steam, you’re not going to make the product wet, but you will dry it out. Between the heat and zero-humidity air, anything that can evaporate from the product will do so. Dry products presents a wide range of problems. Dry things are often inflexible and brittle. Consider if you leave a shirt in your clothes drier for  hours upon hours (do not do this, you’ll probably start a fire), if it survives, it’ll be rough, stiff, and uncomfortable. Dry steam works well enough for a quick cleaning of clothes, but it’s not good for prolonged exposure. This same thing is true in other types of production, consider something like a paper pill or a printing press. If the paper becomes too dry, it might tear inside the machinery. Excessively dry paper is prone to cracking, tearing, […]

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Heating Tech

What Is Dry Steam?

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Despite being a centuries old technology, steam is still an essential part of the industrial world. There are a ton of special uses cases for steam in manufacturing, chemical processing, and elsewhere in heavy industry. We use steam for precise temperature control in specialized vacuum systems, for heating oil and fluids over long distances, for electrical turbines, to push fluids through piping such as in distillation towers, to improve burner efficiency, and for drying things. You Do WHAT?! It turns out that steam is actually incredibly useful for drying things, typically clothe things, but it’s been used on paints and other parts of product drying. You mean for WRINKLES in clothes and pants, right? NOPE. Alright, let’s break out the physics. This is actually something weird and incredibly interesting. Starting with the basics. Matter has essentially three states that you’re going to actually experience in day to day life: Solid, Liquid, and Gas. We all know what these look like, right? Solid water is ice. Liquid water is… well tap water, ocean water, lake water, rain. Gas-water is steam, a big, white, puffy, and usually burn-inducing cloud rising up from those noodles I boiled last night (and got the burn on my hand for). It turns out, we’re not entirely right about how we think of steam. That white, puffy cloud steam makes? It’s not a gas. It’s a liquid. If you physically see steam, the thing you’re seeing isn’t […]

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Heating Tech

What is a Steam Trap?

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Steam based heating systems are similar to hot water heating, but they’re not quite the same. In a hot water system, liquid water enters, circulates, and returns to the furnace. This is not the case for a steam system. In steam, hot steam leaves the furnace, and water returns. This may seem like a minor difference, but it has massive implications to system efficiency. The Science of States When steam cools down, it becomes liquid water and falls down to the bottom of the heating system. On the one hand, this means less plumbing needed to capture and reheat the water. On the other hand, it means we have mixed-temperature fluids in the same space. The condensed water will absorb  heat and hinder the operation of the heating system. It’ll cool down the radiators and the steam itself. The big problem is that water takes a lot of energy to move from being liquid to being steam. It’s not a linear graph. When you heat the water, it’ll eventually rise to the boiling point, about 100 C at sea level, and then the temperature won’t actually increase. The molecules in the water will start to absorb the energy until it’s enough to breaks the hydrogen bonds between them and form steam. As you can see in the chart, we continue to add energy into the system, and between states, the temperature rises, then we hit a limit. When its time […]

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Uncategorized

Why Steam Heat?

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There are a lot of ways to heat your building. Forced air and hot water heat are the most common today, but it’s also possible to use steam.  You might think that steam and water based systems would be almost the same, but they’re actually very different. The Cheap Installation In a traditional hot water system, water flows from radiator to radiator, then back to the furnace to be reheated and recirculated. In a steam system, you don’t need that return pipe. When the steam condenses, it’ll collect at the bottom of the pipe and drip its way back to the furnace the same way it came. The hot steam meanwhile will fill the top of the pipe. This sort of system has traditionally been incredibly popular in tall buildings, such as the skyscrapers in New York city. Being able to use just a handful of stand pipes to provide heat to the entire structure was a massive cost savings. You could essentially build a heating system with half the pipes involved. At the same time, steam heating could be incredibly efficient for a zone-like installation. Many radiators featured shut off valves, allowing a room’s occupant to manually manage the heat. Unused room? Shut off the valve. Too hot? Shut off the valve. It was manual work, but in the right setting, it saved on heating needs. Once one of these radiators became heated, they would also provide heat for […]

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Cooling Tech

Engine Driven Air Conditioners

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The world of HVAC is a very strange place to live some days. We commonly think of air conditioners as being electrical devices. Perhaps the only real exception to that is the air conditioner in your car, which is essentially powered by your car’s engine. In the early days of air conditioning and refrigeration however, the opposite was true: cooling systems were mainly mechanically powered.   The World Before Electricity It’s the early 1900s. The telephone is still considered cutting-edge technology and you can go down to the local train station to send a telegram anywhere in the country. Electricity however, was not quite so common. In 1900, 3% of US homes had electricity. It wasn’t entirely feasible to just throw an air conditioner in your back room. Even businesses wouldn’t have had the easy option of just plugging in an air conditioning system, even if it occupied half their building. At this point, most working-power was mechanical. Factories would have massive boilers, which produced steam, that turned enormous turbines or ran crank systems, that ultimately ran everything in the facility. In order for any particular innovation to take off, it almost had to be mechanically driven. If you couldn’t throw some coal and water in a machine to power it, you probably couldn’t have it.   Steam Powered AC How exactly do we run an air conditioner on steam alone? Every motor in an air conditioner is doing just […]

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Heating Tech

What if the Furnace Runs Dry?

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Everything eventually fails. In the name of safety, we try to account for as many failures as we can, because things end in tears when we don’t. One of the scarier scenarios to consider is when a furnace loses it’s water supply. You might think that the furnace would never run without water, but that’s often not the case. You might also thing “how could it possibly run dry? It’s got an automatic feeder and a pressurized water supply.” And we’ll have to answer, “everything fails eventually.”   Cutting Out the Supply As we’ve brainstormed around the office, there’s at least half a dozen ways that a furnace’s water supply could be cut off, that might not prevent the system from operating. It is terrifying how many of these failures can happen in common, every day circumstances. Pump Failure The well pump to the facility shorts out or has it’s power supply cut off. Water Main Failure The city water supply is cut off due to construction, age, you name it. Facility Pipe Failure A technician closes a valve they shouldn’t, a main supply pipe rusts, hard water clogs a pipe. Internal Leak/Failure A leak inside the furnace prevents water from remaining in the boiler. Shorted Pressure Sensor A short causes a sensor to read incorrectly, signalling the automatic feeder to not-run Failed Water Feeder The feeder has seized up or otherwise just doesn’t feed. Internal Blockage Hard water builds […]

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Heating Tech

Catastrophic Furnace Failure

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Furnace manufacturers are fighting day and night to make home, office and industrial heating safer. In large part these efforts are incredibly successful. When you hear of a home burning down, it’s more likely that someone left their stove on than a furnace malfunctioned. This of course, begs a few questions: Do furnaces still explode? What does it take for a furnace to explode? What happens if it does explode? Failure Upon Failure Depending on the furnace design, an explosion is going to need at least half a dozen separate pieces of equipment to fail or a fair number of absurd design flaws in order for anything to happen. The pressure relief valves have to fail and become stuck shut. The furnace’s controller has to ignore or never see excessive temperature and pressure readings. The entire furnace has to run until it’s built up sufficient heat and pressure to actually explode, which it would likely never do under a regular duty cycle. A pressure explosion needs everything to go wrong. These are the sort of odds that make winning the lottery look easy. Even so, with seven billion people in the world and likely just as many heating systems having been built, failures happen. Just, what doe sit look like? Creating a Failure The only way to see a failure is to make it happen. Luckily, the Mythbusters have done this for us. It goes without saying, do not disable […]

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