How Hot is Too Hot?

Mother Nature is not yet done roasting us with the summer sun. We’ve had a good week or two of cool weather but now Philly is roasting hot. Factoring in humidity, it feels a little over 100 Degrees Fahrenheit outside. Put another way, if we cracked an egg on the hood of lead salesman Scott’s Jeep, it’d probably turn to dust in about a minute. The US National Weather Service has issued heat advisories and warnings to stay inside. Where do we put that boundary, between mere comfort and necessity to live?   Beyond Uncomfortable When we start to see these excessive temperatures proper cooling becomes not a matter of comfort, but of health, life, and death. When the Heat Index breaks past 100 degrees, we start to have issues cooling ourselves. The core of your body wants to be at about 98 degrees. If the air outside of you is above 98 degrees, it can be physically impossible to remain cool. In these situations, any movement or activity outside can make you hotter. The hotter you are, the more you sweat. The more you sweat, the more dehydrated you are. At the same time, excessive humidity will make sweating less and less effective at cooling your body. At some point, it just becomes impossible to remain healthy. You’ll either become too dehydrated or start to suffer heat-stroke and exhaustion from your body becoming too hot. These situations are more […]

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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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Why Do Fans Make Us Cooler?

Good Monday Morning everyone. We’re going to kick off this week with SCIENCE! Specifically we’re going to look at fans and the reason they can cool us down (but not always). Fan In a Box Let’s start with simple science. Can a fan physically cool a room? We can’t rely on our senses for this, we need actual, concrete numbers. As we covered last week, we can trick the senses into feeling cooler with well designed environments. People make for very poor thermometers. For our experiment, we’ll put a fan in a plastic box with a temperature sensor. We’ll also monitor the room for any changes in temperature. We’re going to discover something very important, very quickly: the temperature inside the fan box steadily increases when the fan is on, and the room temperature remains constant. We can discern two important facts from this: Fans do not create cool air or change the temperature of the air on their own. Fans contribute heat to the environment. The heat is easy enough to explain. The fan contains copper windings for a motor and there are spinning parts. Whenever something moves, it experiences friction. Whenever we pump electricity into something, there’s a certain amount of it lost to the environment. The fan creates heat as a matter of functioning. Let’s try something else. We’ll take a computer fan, and put it through a little home-made duct to blow over the tip of […]

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Why Can’t We Crank the Heat AND the AC?

We’re entering the awful, awful season where mother nature will swing between very warm and very cold. Just last week we had a good four inches of snow, a high of forty degrees, and a low below freezing, only for a high of over fifty the very next day. This weather calls for both heating and cooling in some circumstances, but we can’t always give you both.   Fond, Freezing Memories The schools I went to growing up had a very annoying problem: they could heat or they could cool, but they could not do both. This was always problematic and stupid to kid-me sitting at his desk contemplating a textbook bonfire for warmth. Of course, it’s wasteful to run the heating and cooling at the same time, but surely we can just turn off the furnace and crank up the AC? We’ve done it in the car all the time, you just twist a knob and you go from freezing to roasting and vice versa. At small scales, climate control is pretty easy to accomodate. You use air ducts and mix hot and cold air to get the net desired temperature. Facilities with forced air heating and cooling can pretty readily fling themselves from one temperature to another like your car. Other facilities have completely separate systems for heating and cooling. There might be a little split AC unit in every room and a master hot water heating system. […]

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Why is it Snowing in April?

We work in an industry all about controlling our indoor climates, but we’ve never really talked about our actual, natural climate. Why is it snowing in APRIL. We’re a few days into April, many days into Spring, and there’s snow in the ground. A few days ago it was sixty degrees outside and I was tempted to cook up some burgers on the grill and getting ready to dust off the lawn mower. What is with this weather?   Global Weather The first thing to understand about the weather is that it’s not a local thing. The air all over the world is constantly moving, constantly carrying moisture, changing pressure, and changing the air temperature. Our local climate is controlled by our local geography and exposure to heat from the sun AND by events occurring thousands of miles away. On the one hand, we have the sun warming the ground around us, but on the other hand, air can move at hundreds of miles per hour in the jet stream. We’re experiencing this battle between energy entering our environment and just as quickly being effected by air from cooler environments. What do we expect for our local environment (Philadephia/the US Northeast)? Highs in the 50s and 60s, lows in the 40s. We expect a good bit of rain fall, per the old saying “April Showers bring May Flowers.” That is, it’s a wetter season for us as part of Spring. We’re […]

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Why is my Building Grounded to the Water?

In the US, we commonly have three prongs for our electrical devices. Two of these deliver the AC Current, being both positive and negative over time and a third which goes to Ground. This is a safety thing. Whenever there is an electrical short, a static build up,  or even a lightning strike, we want to divert that somewhere safe. The safest place for these excess charges is straight to the Earth, the ground below us. As big as the Earth is, it basically has an absurdly powerful negative charge. You can disperse power into the ground and it’ll dissipate safely. Getting to Ground It is essential for every electrical and metal component of a building to be grounded. This can be a real nightmare to actually implement. You need something that is going everywhere in the building. On the one hand, you could run additional conductors, miles and miles of additional conductors, or you use the one conductor that’s already there: the water pipes. That’s right, older buildings ran their electrical grounds straight to the plumbing. On the one hand, this does kind of work. The copper pipes in most buildings are excellent conductors. These pipes are going to make contact with the ground at some point. If there’s a well, the pipes are going deep underground. If there’s municpal water, they’re still going to be several feet below the surface before long. For the early days of electrified […]

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The Science Behind Insulation

Insulation is essential to a comfortable and efficient environment. The essential point of insulation is to isolate your indoor environment from the outdoor environment. We want to control the flow of heat, energy, into and out of our workspaces as much as possible. To pull this off, we need to find the worst conductors and most obstructive blockers in history. We need to make the opposite of a radiator, a blocker.   Blocking the Heat Insulation works against three basic ideas: Conduction Heat which is passed through a surface. Consider the copper pipes used to heat a home. The heat spreads through them. If you hold a torch to one end, the pipe will be hot even feet away from the heat source. It conducts the heat. Convection Heat which moves with the air. A typical gas or electric oven uses convection. The air is heated and circulated around the thing that is being heated. Radiation Put down the hazmat suit. We mean heat caused by intense light. This is the sort of heat used in laser cutters. This is the heat of the sun and all its powerful infrared and ultraviolet rays. This is the kind of heat that turns a sitting car into an oven. The most comment type of insulation is going to work against conductive heat flow. This is that fluffy material behind your walls. These insulations are rated with an R-Value, their Thermal Resistance to […]

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Blizzard Testing Your HVAC System

Can you tell it’s winter yet? Is it safe to come out yet? Here in the North East, Mother Nature has just finished her first major storm of the season. We can confirm that no one at Procure is interested in living in the far, Arctic North after experiencing days-straight of subzero temperatures. We were within spitting distance of water being able to freeze before it hits the ground. Along the way, we also got to push our heating systems to their edges and see where we really should’ve built things differently. Edge Case Testing During normal operation, it’s doubtful you’ll ever see something out of place in a well designed heating system. If you engineered a system for an average winter, then chances are you can turn your home or office any temperature you like during average weather. It can be ten degrees outside, but a sweltering 92 inside. When nature throws you a curve ball you get to see where the weaknesses are in your heating system. More extreme weather, is more stress on the system. More stress is going to show you what parts can’t keep up. This breaks down to a problem of numbers. The sum-total of heat you can put in the air is XX. Your building loses heat to the air at a rate of YY. Severe winds increase this rate by ZZ. In order to stay warm XX needs to be greater than […]

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Unfreezing a Freezer

How do you run your refrigeration hardware through the winter? How far does our industry go to keep a fridge running in the winter or a hospital chilled in a blizzard? There are a number of technologies at play, all working to manipulate the hardware to do their bidding. These are collectively called Defrost Controls.   Let Nature Take Its Course The simplest defrost system is little more than a few switches and a timer. In many systems, the greatest concern is that the evaporator coil may freeze over. This is especially common with industrial freezers. This is a year-round problem and it can be caused by staff frequently entering and leaving a freezer. The freezer temperature increases and many refrigeration systems end up running for entirely too long. The evaporator coil builds up ice from being chilled too much. In configurations like this, the simple solution is a time delay. The compressor shuts down, but the evaporator fan is run for an extended period, forcing relatively warm air over the coil. Whatever ice was there melts and the system can return to it’s regular cycling after the defrost cycle finishes. This can be set to run on timers or in more advanced systems, as necessary using temperature readings. In some installations, it can even be boiled down to a timer which triggers the cycle once every 24 hours and just turns off the refrigeration system for an hour to […]

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Oil Burner Ignition

Gas systems need either a hot surface or a pilot light to get started, but not oil systems. Why the difference? It boils down to the fuel being fundementally different. Fuels like propane and natural gas enter the combustion chamber in a gaseous state. Once part of that material is lit on fire, it will conduct the heat and light the entire fuel stream. This doesn’t work for oil.   The Major Difference Oil enters the combustion chamber as a liquid and it requires extreme heat to light. This makes a pilot light nearly pointless, as it would be just as easy to light the main burner as the pilot. A hot surface igniter would be a viable option except it needs to be in the path of the fuel stream, where it would endure the direct-heat of the flame throughout operation. Oil as a fuel source is a completely different beast, unrelated to gas heating. These problems all stem from heating oil’s chemical make up. It’s a cousin of diesel fuel used in over the road trucking, but thicker. It shares some of diesel’s inherent safety. Heating oil and diesel require either extreme heat or extreme pressure. This is why diesel trucks don’t have sparkplugs. At least for an engine’s needs, a spark wouldn’t work well in the long run. They generally remain in a liquid state as well, rather than readily becoming gasses.   A Really Big Spark […]

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