Your Yearly AC Checklist

It’s a slow day in the office and not a one of us here can really focus on our research. The weather is beautiful outside. The sun is shining, there’s a few little clouds drifting lazily in the endless blue sky. The birds are chirping and going after a feeder dangling lazily from a window across the street. I’d drag my computer outside and work from the sidewalk, but Lead Salesman Scott said he’d take my spot by the AC vent. Ah, right, the AC. We should get ready to turn that on. A Long, Harsh Winter Your air conditioner works hard all summer and gets to relax for the winter. Except that it doesn’t. The winter is perhaps the harshest time for your air conditioner, when it’ll have some of the highest risks of taking damage. All summer long, if something’s gone wrong, you’ll notice and get it fixed. In the winter? Not so much. Ice could crack a coil, debris could block up the coils and fans, a seal could fail, a rat could chew through some wires, and more could go wrong. We believe in preventative care as much as possible. Your HVAC Professional should do most of the work of inspecting your air conditioner, BUT there is a little bit you can do. Primarily speaking, you should clear all the dirt, debris, leaves, and other things away from the condenser unit. Keeping this area clear will […]

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Cleaning With Light

If you’ve spent any time under the sun on a long, hot, clear day, you’ve probably gotten a wicked sun burn. I may have overcooked myself a bit during our nice Easter weekend too. This brings up an interesting thought: what happens to airborne pathogens exposed to the same light? A sunburn is the result of millions of skin cells being irradiated by UV Radiation. Sunlight contains UV, Ultra-Violet, which can cause skin cancer in high enough exposures. It’s not dangerous in the same way X-Rays are, those would be lethal with a few hours of exposure. UV is weaker, but it still wreaks havoc on small cells. Messing With Molecules Let’s start out with some basic physics. We’re going to ignore the whole “particles & waves” thing for now and just say that all light is made of particles called Photons. When you turn on a light, it spews out photons, that bounce off the wall, lose some energy, strike your eye, and then you perceive the ‘color’ of that photon. What happens is the photon rams a cell in your eye with a certain amount of force, it’s energy, and that tells you it’s ‘color’. To the 3 physicists reading this, shut up. I know it’s more complicated. The problem happens when we give that photon more speed, more energy. Eventually, the photon moves too fast for our eyes to detect. It’s not visible light any more. It […]

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Don’t Clean Your Coils

With a Pressure Washer We previously mentioned that clean evaporator and condenser coils are happy coils. Dirt and debris builds up, restricts airflow, and prevents the coils from doing their job. Recently we realized, while there is a right way and a wrong way to do everything, there is a really wrong way to clean your air conditioner. High Powered Cleaning Suppose you need to clean something that’s incredibly ground in. You might scrape at it, or find someway to break up its edges and get under the layer of dirt to pry it up. It’s going to take forever, require a lot of work, but eventually gets the job done. What if you could instantly apply all that force to every weak spot in the dirty build up, and just blast it apart? This is in part, how a pressure washer works. On the one hand, we’re applying a massive amount of force in a small area. Any imperfections or weak points are going to make the substance fracture. The water will shoot through the dirt, and then blast outwards and send it to bits. On the other hand, water isn’t exactly abrasive like sand, BUT it will carry away a little more material with every drop that hits. Detergents can be added to the mix to chemically breakdown whatever it is that’s getting sprayed. If there’s an especially solid build up, you can essentially blast and melt it […]

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How To Measure Air Quality

Like all things, we can measure air quality scientifically. We can get a number that says just how gross the air in your facility is. Not only that, but we can figure out what particular type of problem your air has. There’s more to air quality than just saying it’s good or bad. The Troublemakers There are three commonly examined areas for air quality. We have different ways to detect and measure each of them, but these are typically available all in one tool or device. Particulate Matter There are tiny particles in the air, often harmful chemicals we don’t notice individually. Think of things like the exhaust from a car. That exhaust is made of billions of tiny particles of burned fuel and even metal shavings from the engine. These can have negative health effects. Particulates from cars could play a role in Alzheimers Disease. These can detect bacteria, viruses, and mold as well. Sensors for these are rated in their measuring sizes, 2.5 microns and below, 10 microns and below, etc. Your hair is about 40-70 microns thick, for comparison. Volatile Organic Compounds The rule of thumb is that a VOC is something you smell and notice. That’s not always the case, but it’s a good guiding post. These chemicals are highly reactive, dangerously so. Examples of these are things like cleaning chemicals, gasoline, and paint. They’re things you should try not to breathe in. Carbon Dioxide This […]

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Indoor Air Quality

Heating your facility is important. It’s probably in the top ten most essential things to keep your workers and customers happy. It’s not the only thing. Warm air is useless if people can’t stand to breathe it in. Over time, air will get stale and become unpleasant to breathe. We need to not only heat the air, but clean it. What Is Stale Air? The air around you isn’t pure (unless you’re in a hyperbaric chamber, but that’s an entirely different can of worms). More accurately, the air we breathe is more like being in the ocean: it’s full of microscopic things floating around. If you’ve seen sea water, you usually see little things carried around in it. The same is true for air, but most of the things floating us are too small to see. Typically the air in a busy facility will be carrying: Skin Flakes and Hair Bacteria Viruses Mold Trace Chemicals (from cleaners, machinery, etc) Vaporized Sweat Chemicals from Oral Bacteria (Bad Breath) Particulates from Fabric, Food, and Product Offgassing Air becomes stale largely as a result of all these things becoming to abundant. The human body is incredibly perceptive to these things. We can smell, taste, and even feel that the air is not clean. There’s no way to just hide the problem either. Some scents can be fought off with aerosols, candles, and other products that alter the air. The only problem is that […]

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NASA’s Water Recycling System

After last week’s Wednesday post, Lead Sales Guy Scott has told me no more sewer blogs. He really values his breakfast. Luckily for me, that’s a request I’m happy to oblige, with a loophole a mile wide: you don’t call it a sewer when it’s in space. In space, we call that Waste Water Reclamation or Recycling. Water In Space Water is a basic human need. If there is no water, there will eventually be no humans there either. Its probably possible to have life without water, but that won’t be us any time soon. We’re giant blobs of water wrapped in a soft, squishy membrane for all intents and purposes. We’re 60% water, which makes us water with some contaminants. Our bodies however, constantly excrete that water. We sweat, exhale water vapor, and lose it in our waste. Consequently, we need to constantly refill ourselves with more water. On Earth, this isn’t much of an issue. We can return the water to the environment and find more. If necessary, we can build an enormous processing plant and turn ocean water into drinkable water. In space however, that’s not an option. In a best-case scenario, it costs about $2500 per POUND to put anything in space. Cost of Water Per Astronaut Without Recycling1/2 Gallon of Water X 8.34 LBs/Gallon X $2500/LB$10,425/Day Per AstronautWater For The Longest Stay on the International Space Station438 Days x $10,425/Day$4.6 Million Per Astronaut It would […]

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Fall AC Maintenance

It’s getting cooler outside. The high today in Philly isn’t even 80 degrees. Just a week or two ago we couldn’t go a day without seeing 90. In another few weeks, we’ll be struggling to see the 70s and we’ll be turning to warmer clothes for the start of fall. As with all things, that means now is about the best time to prepare for winter with some pre-emptive maintenance and cleaning.   We’re Going to Maintain Something… We Won’t Be Using? It’s always best to work on things when you don’t need them and better still to work on them just a little ahead of time. The weather outside is nice and pleasant right now. You can walk outside in a T-shirt and not feel like your arms are going to freeze off. It’s a good time to do any outdoor work before mother nature gives you a nice, awful cold for your troubles. In the case of your air conditioner, there’s a fair bit you can do to get ready ahead of the season. You can clean the area around your condenser, your HVAC contractor can clean out the drainage connections for the drip pan, you can order a protective cover to keep your condenser free of debris throughout the winter, and you can do one last inspection for any worn parts. There is some logic to all of this. Debris is going to trap water from rain […]

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Engine Driven Air Conditioners

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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Freezing a Freezer

It’s the very end of fall, bordering on winter, and we’re going to look at air conditioners and refrigeration. Every year, someone learns the hard way that you both can and cannot run an air conditioner in the middle of winter. Let’s get to it before someone else learns a hard, expensive lesson.   Who Runs the AC in WINTER? Someone out there will ask, so let’s head it off sooner than later. In an ideal world, you could pull in fresh, outside air, particularly when it’s cooler outside to cool your facility. This works in homes and even small businesses, but there’s challenges when you move into specialist industries and larger scale operations. Hospitals can’t just open the windows, as it can expose the patients to bacteria, viruses, and allergens. Restaraunts can’t leave their frozen food up to mother nature’s whims to keep it cold and safe. Large data centers need to be sterile and cool year-round, to the point that the air outside cannot easily keep up against the heat generated inside. Manufacturers in numerous industries need cool areas, for chemical work, storage, freezing food, and so on. In all of these cases, nature is too unpredictable, too unreliable, or just too complicated to fulfill our needs. These places need to run air conditioning and refrigeration even through the coldest and darkest of winters.   The Freezing Problem Regardless of application, all refrigeration systems have one big nemesis […]

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Measuring the Heat

Have you ever wondered how your heating system knows to turn on? Or to turn off? You could say “the furnace controller tells it to” and “the thermostat tells it to,” but that’s not the whole picture, is it? We need a way to measure the temperature inside the furnace and inside our homes. It has to be durable, reliable, and affordable. It doesn’t have to be precise, but it must be right every time it’s measured.   A Complex Web of Technology There are a staggering number of ways to control a furnace through temperature input. A brief and nowhere near all-inclusive list of techniques include: Gas Expansion Tubes, Bi-Metal Switches, Bi-Metal Coils, Thermocouples Driven by a Pilot-Light, Thermistors, and of course modern IR Temperature Sensors found in your enthusiast-chef’s kitchen. These devices are all in some way sensitive to the heat. Bi-Metal systems expand as temperatures change. Measuring the expansion reads the approximate temperature. Gas Expansion Tubes have an internal change in pressure as temperature changes. The pressure can be used to calculate temperature. Thermocouples generate an electrical current when they’re heated. Measuring the current allows you to determine the temperature. Inside a furnace, they’re often heated directly by the pilot light or burner to read flame temperatures. Infrared Thermometers measure “Blackbody (Wikipedia Link)” radiation, but aren’t all that effective around metals or the air. And lastly, we have the humble Thermistor, which varies it’s resistance based on […]

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