Direct Exchange Geothermal Heat Pump Essay Example

Direct Exchange Geothermal Heat Pump Essay Example Direct Exchange Geothermal Heat Pump Essay Direct Exchange Geothermal Heat Pump Essay Direct exchange Direct exchange geothermal heat pump The Direct exchange geothermal heat pump is the oldest type of geothermal heat pump technology. It is also the simplest and easiest to understand. The ground-coupling is achieved through a single loop circulating refrigerant in direct thermal contact with the ground (as opposed to a combination of a refrigerant loop and a water loop). The refrigerant leaves the heat pump appliance cabinet, circulates through a loop of copper tube buried underground, and exchanges heat with the ground before returning to the pump. The name direct exchange refers to heat transfer between the refrigerant and the ground without the use of an intermediate fluid. There is no direct interaction between the fluid and the earth; only heat transfer through the pipe wall. Direct exchange heat pumps are not to be confused with water-source heat pumps or water loop heat pumps since there is no water in the ground loop. ASHRAE defines the term ground-coupled heat pump to encompass closed loop and direct exchange systems, while excluding open loops. Direct exchange systems are significantly more efficient and have potentially lower installation costs than closed loop water systems. Coppers high thermal conductivity contributes to the higher efficiency of the system, but heat flow is predominantly limited by the thermal conductivity of the ground, not the pipe. The main reasons for the higher efficiency are the elimination of the water pump (which uses electricity), the elimination of the water heat exchanger (which is a source of heat losses), and most importantly, the latent heat phase change of the refrigerant in the ground itself. While they require much more refrigerant and their tubing is more expensive per foot, a direct exchange loop is shorter than a closed water loop for a given capacity. A direct exchange system requires only 15 to 30% of the length of tubing and half the diameter of drilled holes, and the drilling or excavation costs are therefore lower. Refrigerant loops are less tolerant of leaks than water loops because gas can leak out through smaller imperfections. This dictates the use of brazed copper tubing, even though the pressures are similar to water loops. The copper loop must be protected from corrosion in acidic soil through the use of a sacrificial anode or cathodic protection.

Are You One of These 4 Toxic Workplace Personalities

Are You One of These 4 Toxic Workplace Personalities There are a million ways to screw up at work, and we like to think we avoid most of the obvious pitfalls. But here are a few work types you might not realize you resemble from time to time. 1. The MinimalistYou know who you are. Someone asks you for a status update on a project and you answer, â€Å"I did my part,† without following through. How much longer would it take you to trace that project through the chain and give a more comprehensive answer? To take responsibility for the task, not just your fraction of a task? You won’t be able to do this every time you’re asked, so why not take the initiative when you can and go the extra mile?2. The Negative NellyYou might think you’re an upbeat, positive person. But it’s possible you’re the workplace downer. Do you groan at each new daunting project? Weigh the cons before the pros? Complain about the extra work and hours, rather than get psyched about that new high-profile project? Make sure you keep the glass half full and distinguish yourself as a leader among your colleagues.3. The DisappointmentYou think you’re a hero because you take on so much more than everybody else- but that’s also more than can be reasonably expected. Overcommitting can sometimes lead to underperforming, missed deadlines, monster to-do lists, and disappointment. You certainly don’t want to be guilty of the opposite (never taking extra work on), but if you do step in to pinch hit, remember to make sure you have your stance in order.4. The ShockerYou’ve taken on a bit more than you can chew, and things have been going in a disastrous direction. But you haven’t let your boss in on the details, and as the big presentation rolls around, you have to drop a bomb. If only you’d shared the difficulties as they popped up along the way- your colleagues could have helped out before the situation deteriorated. But you didn’t. And now†¦ disaster.These workp lace traits turn up in every office. There’s always someone guilty of these office faux pas, and- if you aren’t careful- it could be you!Are You a Boss Botherer? Be Sure to Avoid This Workplace Behavior