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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Upgrade Season

It is almost comfortable outside. Mother Nature hasn’t yet committed to the warm 70s, but we have a good few days of 50s and 60s ahead. We’re going to have about two months where our HVAC systems can sit nearly idle, untouched and unneeded. This is your ideal corridor for major maintenance and installing new systems altogether. Depending on the scale of your facility, you may well need it. Perfect Weather From a comfort-perspective, the very beginning of Spring is an ideal time. We’re well acclimated to cool weather and the slow move into the low sixties and seventies means we can be comfortable without any HVAC equipment. We can open the windows for a few days and no one is going to be inconvenienced by it. We can shut down the building’s plumbing and install temporary accommodations outdoors and it won’t be painful or disruptive to your employees for a few days. This rare window is different from the fall. Being cold is inherently uncomfortable and harder to compensate for than being too warm going from winter into spring. In the fall, if you get a very cold day, there’s little you can do to heat the building without buying every space heater in the city. In the spring if you get a warm day, tell your employees it’s Casual Friday all week, shorts and t-shirts approved. Open a window or leave the front doors open. The shifting weather […]

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Clean Your Coils

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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Portable HVAC?

Finally, back to our regularly scheduled programming! There are times when your building has neither heating nor cooling and every day without them is literally costing you hundreds, thousands, or even millions of dollars. This could be for near any reason. Maybe your furnace system is completely shot or your mechanical system was destroyed by a natural disaster (though the remainder of your facility is intact). Luckily, there is an industrial-scale solution.   HVAC On Wheels Your facility needs a heating or cooling source, but the location actually is pretty irrelevant. New York City pipes in hot steam from far off generator plants, essentially providing a heating service to the entire city from a few efficient locations. The heating or cooling set up doesn’t actually need to be in your building, just close enough that we can connect to it with insulated pipes and not lose too much in the transfer distance or have excessive costs for the connection materials. This can be a significant life saver in the right situations. There are service providers which will rent out a near complete HVAC set up built into a few large trailers. They’re designed essentially as portable, packaged systems. Everything is tightly integrated to work with the available space and resources. These systems can be hooked into a building with standard pipes and fittings in a matter of days, providing heating or cooling to keep the business running. The alternative is […]

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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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History of Refrigerants

The concept of mechanical refrigeration starts back in the 1750s. Researchers knew nothing about cooling except that pressure and gasses somehow played a key roll in absorbing and removing heat. In these early days, everything was tried as a refrigerant: ammonia, alcohol, air, carbon dioxide, and more. It was the days of trial and error to create the robust understanding of physics and chemistry we have today.   Low Temperature Boiling The first experiments in refrigeration used Ether and Alcohol, which are readily evaporated. At sea level, Ether boils at 94F and Alcohol can boil as low as 151F, depending on the exact chemical form. Sea level is important here, as pressure changes the boiling point. Lowering the pressure causes a decrease in the boiling point. These gasses with low boiling points were ideal for early experiments. The first experiments used vacuum chambers and potentially some custom hardware. There isn’t a lot needed to build a basic vacuum chamber. A jar with a good seal, a hose, and a pump can create a vacuum. An observable refrigeration can be done with almost no special equipment at all. At this scale, cooling was possible, but not feasible. Alcohol, Ether, and other chemicals were common and easy to acquire, but no one was going to put a chunk of meat in a vacuum chamber, cover it in alcohol, wait for it to freeze, and try to store it somewhere. There had to […]

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Rooftop vs. Roof Mounted Systems

When we say “roof top air conditioner,” your first thought is probably any old machine bolted to the roof and blasting air into your building. This is only partially correct. There are specialist systems designed to be roof mounted and regular systems which simply can be roof mounted. The difference is sort of like a big rig versus a regular pick up. They’re both trucks and both can haul a trailer, but only one of them was built to only haul trailers for it’s entire service life. Roof Top Units The easiest way to think of these is as a packaged system. A roof top unit is a fully self contained air conditioner and heating system, in one mass of hardware, that will blast air of an arbitrary temperature into your ductwork. In some ways this makes things easier. You don’t need to have separate systems, you have a single, bolt in system that does all the work in one place. Units like this take advantage of being pre-assembled at the factory. Everything about them is optimized from the start for the best possible performance. There can be tighter tolerances in assembly because it was all built at the factory. It’s also likely to never be seen by a customer, being tucked away on the roof, it won’t take up indoor space either, except for the duct work. It’s a really attractive idea for a business to consider. There are […]

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Why Are There So Many Fins in a Coil?

If you look really close at your air conditioner’s evaporator or condenser coil, you’ll see a ton of tiny fins sandwiched between two tubes. You might ask yourself, why are we making this so fragile. A screwdriver could puncture these fins with just the smallest bit of force, let alone what some ice could do. Why are we using such tiny parts instead of just a few, massive fins or something more robust?   Old Radiators Let’s start with a trip to the past: the classic heating radiator. A radiator like this is just another type of heat exchanger, almost the same thing as your air conditioner’s coils, but designed to heat the home or office. These were massive, robust pieces of equipment. They weighed hundreds of pounds of cast iron and could break your foot, leg, and back all at once during a botched installation. These work on the same principle as other heat exchangers: we change the temperature of the heat exchanger, and it in turn changes the temperature of the air. With such beefy components though, it requires a lot of water or steam to make any significant changes. Sure, the radiator will get hot enough to fry an egg or reduce just about anything to a piece of charcoal, but it doesn’t have a lot of contact with the air. It ends up being slower as a result.   Surface Area When we radiate or absorb […]

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How to Tame Your Cooling Costs

Air conditioning is expensive, but essential for most of the world except perhaps the arctic circle. It improves employee productivity and attracts customers on the hottest of days. Unfortunately,  it also makes an electric meter look more like a helicopter, buzzing along as we suck down ever more watts in search of comfort.   The Little Things Use light-colored windows blinds and curtains. Every place that light gets into your building is some place it’s going to raise the temperature. Light ultimately creates heat, the sun is giant, nuclear, laser ball. If we can make sure its light falls on reflective things, like lighter colors, curtains and blinds, we can reduce the amount of heat generated inside the room. It would be impractical to close off grand entry ways with curtains, but everywhere else is probably fair game. Even some window blinds in the office can reduce the heat coming in by half, while still keeping the room fairly bright for your staff. Dial back the temperature The greater the temperature difference, the harder the air conditioner has to work to maintain that difference. Remember that you need to only create apparent comfort. If it’s 100 degrees out, your employees and customers will probably be grateful for anything less than 85 degrees. You don’t need to make the office 60 degrees. Close the doors Ensure you’re not venting cool air wastefully. Keep the doors closed or install a closing mechanism […]

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