MAY 05

Since this 'geothermal' system simply works on the difference between air and subsurface ground temperatures, the system will strive to reach entropy at which time it will no longer work to heat (or cool). The thermal conductivity of the ground is quite low so it will happen.

True geothermal systems use heat which is generated in the ground by natural processes (like radioactive decay, magma body proximity etc). They cannot reach entropy.

Come on people it is just a heat pump that uses the ground instead of the air. This is not rocket science, you can get one for you home easy as pie.
- It works better than a air heat pump because the ground temp is closer to where you want to be than the air temp.
- The backup system is not a extra cost of geothermal, a air heat pump uses electric or gas as back up heat. For those really cold days that it can't extract enough heat for the outside air. Note the backup system is used much less in a geothermal system than air heat pump because when the air is -10 degrees the air heat pump has already stopped working and gone to backup; while the ground is below 20 feet is still warm.
- Yes heat moves slower through the ground than air, that is why they underground pipes are so long. The amount of pipe you need is based on the type of ground (dirt type and amount of water). In fact if the water table is high enough the heat transfer is much faster than in air.

The big drawback is that you have to install the pipes, so up front cost is higher. So you have to look at the cost of the whole life of the system.

The new airport heating system will save 500 tons of GHG a year. A single 747 flight across the USA and back will pump out more GHG than that!

From a climate standpoint it is trivial to the point of denial for an airport to be focusing on anything other than reducing jet GHGs. It is like a morbidly obese person trying to lose weight by trimming their fingernails.

But from a dollar savings maybe it makes sense. Hard to see why it is a EcoGeek story through.

If one company saves 50,000 gallons of heating oil a year, they have my vote! Good on them.

True, it may not be a huge GHG saving compared to flights but hopefully other people and businesses will read about this system. It's all about education, and I see that as an important way to reduce flight numbers and improve aircraft efficiency and so on ....

I agree that it is a good thing that a company does something to reduce their climate footprint.

What I don't understand is why it is "news" when a company does so much less than what is needed. The climate science is clear that we need to cut climate pollution about 2% per year for the next 40 years. And the project highlighted here doesn't seem to get anywhere close to even a single year 2% cut in GHG for an airport.

It is a "dog bites man" story in which yet another company does less than is required to cut climate pollution. If it is going to be covered it would at least be helpful to readers to highlight this "geeky" but base level point.

A parking lot seems like a bad place to put a cooling system. They should consider covering the pavement with solar panels, which also could shade and keep snow off the cars.