The Certified GeoExchange Designer (CGD) Plus course material offered by IGSHPA and accredited by the Association of Energy Engineers (AEE) has been available in Imperial units for several years. With IGSHPA Chapters outside of the U.S. there is a demand for the course material to be delivered using metric units. The first metric version of the course has been delivered (online) to several participants in the United Kingdom.
The translation from Imperial to metric units takes into account the differences in how HDPE pipe is referred to in North America (based on the inside diameter of the pipe) to the metric sizes (based on the outside diameter. (refer to the blog article describing the differences in pipe sizing in North America compared to European sizes).
Both the Imperial and metric versions of the course are built on the process needed to optimize the design of a building and building systems to work well with a ground coupled heat pump (GCHP) system. The design process is different than that needed to design a conventional heating ventilation and air conditioning (HVAC) system. The critical difference is the fact that a ground heat exchanger (GHX) touches a finite mass of earth...the amount of energy that can be transferred in and out of it is limited by the thermal properties of the soil / rock, the configuration of the heat exchanger and the balance between the heating and cooling loads of the building they are connected to.
Most conventional HVAC systems are connected to an infinite energy supply (a gas line or electric grid). Only peak heating and cooling loads are needed, and as long as someone pays the utility bills, the building will be heated. Heat is dissipated to the atmosphere, and the cooling tower or air cooled equipment simply dissipates heat to the outside air and the wind dissipates the heat.
The course material helps provide the answer to 2 questions:
The material progresses from the use of an energy model as an important design tool used throughout the design process, to testing the soil and/or rock the GHX will be built in, to detailed GHX and mechanical system designs and specifications, to construction, commissioning and operation of the system.
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.