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Heat transfer fluid is used to move energy to and from the ground to a heat pump in any ground coupled heat pump system. In a hot climate energy is transferred from the building to the ground by heating water to a temperature higher than the ground temperature. Fluid temperatures from the heat pump can reach temperatures as high as 90° to 100°F (32° to 38°C), In a cold climate, however... Heat pumps will run under a fairly wide set of operating parameters. They will work with a wide range of entering water and air temperatures and flow rates. But just because a heat pump will run under a wide range of conditions doesn't mean they will operate efficiently. To maximize the efficiency and capacity of a heat pump, a designer should become familiar with the specification catalog supplied by the manufacturer.   The land area and amount of pipe needed in a horizontal GHX is directly related to the thermal properties of the soil it is buried in. This in turn relates directly to the cost of installing a GCHP system...and if your customer feels it's too expensive to install they typically resort to installing a conventional system and forget about the heat pump system. To make it worse, that potential customer will often tell his or her friends they considered it for their home, but it was too expensive...they'd never get their money back. Is there any way of avoiding that? The International Ground Source Heat Pump Association (IGSHPA) recently adopted a new syllabus for the CGD commercial geothermal design course. On Dec 2 and Jan 6, at 11:00 am till noon CST, I will be providing a free, 1 hour webinar as an introduction to the new course syllabus. You must register to get a password for the intro (we are limited to 25 participants). The CGD course focuses on... The Assiniboine Park Zoo in Winnipeg, MB is building an International Polar Bear Conservation Centre and the Journey to Churchill Polar Bear exhibit that will be opened to the public in 2014. The four buildings under construction for the exhibit (the Conservation Centre, Tundra Cafe, the Gateway to the Arctic Exhibit Building, and Aurora Borealis Theatre) are connected to a common GHX. The GHX design is unique in that it... GCHP systems are being employed in a wide range of applications. Many systems have been installed in residential applications, mostly homes outside of urban areas, where there is space to install a GHX or connect to a water well. School boards started installing GCHP systems in the 1980's and '90's. The Lincoln County School Board in Nebraska has converted many of their existing schools and all new schools are designed with geothermal systems. Even a 1.5 million square foot (140,000 m2) retail shopping mall is being built with a GCHP pump system. What about applications for the technology in agricultural applications? Amory Lovins of the Rocky Mountain Institute has long advocated the concept of "negawatts". For some reason many people have difficulty equating reduced energy consumption as having the same value to a utility as generating new energy... especially the people running the utilities. Think about it. If you reduce electricity in your home by religiously turning off lights that don't need to be on and reduce your energy consumption by 1,000 kWh this month, those 1,000 kWh can be sold to another consumer. Is that any different to the utility than building a generator to produce 100 kWh to sell to that other consumer? Actually, it is.... You're almost certainly reading this from your computer. This story is stored on a server somewhere. Servers use electricity...the numbers of servers needed to give you access to all this information you and the rest of the world are using is a significant percentage of the world's electricity consumption. Google is the largest single electricity user in some states . One Austin utility sends 8.5% of its power to server farms. Electricity is not only used to power the computers, but to keep them cool. Connecting the cooling systems to the ground Energy modeling is usually considered time consuming and it's tedious. One of the primary reasons it's done at all in many architectural and mechanical engineering offices is simply to comply with LEED, the building code or various incentives. All too often the person tasked with developing the energy model is the least junior technician or engineer in training in the office...the person with the least experience about buildings and systems, and how they can impact the energy loads. Energy modeling, when used as the design tool... It's been a long time in the making, but the International Ground Source Heat Pump Association (IGSHPA) / Association of Energy Engineers (AEE) course for the design of large scale commercial ground coupled heat pump (GCHP) systems is being delivered for the first time. The Certified GeoExchange Designer (CGD) course material is built around a design process needed to optimize the cost and efficiency of a GCHP system and GHX needed to allow the system to operate. |
Ed Lohrenz
In my blog I'll be expressing my opinions about what I've the learned about ground coupled heat pump (GCHP) systems over the last 30 years. I've been very fortunate to work with many interesting people who are passionate about this technology...engineers, geologists, mechanical contractors, drillers, excavation contractors...in different parts of the world. I've learned a lot from them and will be using this forum to pass on some of the things I've learned and feel are important. Please feel free to use this information if you feel it's worthwhile...hopefully you can avoid some of the same mistakes I've learned from. Archives
November 2016
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