If you look for it, you'll find a lot of "waste" heat in some buildings...and owners or tenants are paying a lot of money to get rid of it. At the same time they are paying a lot of money to purchase energy from a utility to heat their building. What a waste! Buildings are used for many different kinds of activities. Many of these activities and the equipment...
associated with them generate heat. In other articles I've talked about recovering waste heat from obvious examples such as ice rink refrigeration plants. (district heating, and free heat), and waste heat from combined heat and power systems, but there are many other waste heat sources that can be captured and used to either heat the building directly, produce domestic hot water, or rejected into the GHX if it can't be used. Heat stored in the GHX can be extracted later in the day, or even several months later.
Grocery stores require a lot of refrigeration to keep meat, dairy and produce cool or frozen. Computer server rooms in office buildings require cooling year round. Elevator motors and pumps require cooling whenever the building is in use. Office equipment, lighting, etc. produces a lot of internal heat gain. Less obvious examples are found in medical office buildings. Equipment such as magnetic resonance imaging (MRI) equipment needs cooling round the clock...cooling liquid cannot be shut down to an MRI unit without damaging it. Linear accelerator equipment used for treating cancer produces heat even when it's in standby mode. Much of the specialized medical equipment is liquid cooled and is easily adapted to be cooled by liquid directly from the GHX or by water to water heat pumps that can provide accurately controlled chilled water.
Heat from the equipment can be used to balance energy loads to the GHX, allowing the designer in many cases to reduce the size of the GHX. In colder climates, using waste heat to provide space heating, domestic hot water, or even to melt snow at the entrance to the building or in the parking lot area provides significant benefits for the owner...both in capital cost and/or in energy cost savings.
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.