geothermal installation instructions

There is no one set of finite geothermal installation instructions or standards to which installers work. It's a fairly invoilved and specialised process, so it's not really something for the DIY installer to attempt. However, there are guidelines and good practice which really form the closest things there are to geothermal installation instructions.

Part of the reason there are no definitive geothermal installation instructions is that each installation is different. Due to the nature of how geothermal / ground source heating and cooling systems work (ie in conjunction with mother nature and what she's provided in your available land), the exact specification of a system depends to a large degree on the installation context. Hence geothermal installation guidelines, rather than geothermal installation instructions.

The installation context also has a large part to play in selection of which exact install is most suitable to have done. What surface or ground water is present, what soil and rock topoligies are prevalent locally, physically what footprint of land you have available to place a geothermal installation in should all be factors a geothermal installer takes into account before speccing your system. Similarly, where you are in the world will also play a part. In relatively warm climates, such as those in the United States, there will be a larger heat differential between ground and target building, thus there will tend to be more flexibility in selection of ground loop layout and size.

The two basic approaches are:

Horizontal ground loop either in soil or rock, or in water

Vertical ground loop installation, usually within rock

Both can use straight or 'slinky' piping, and this piping carries a water / antifreeze mix.

Working from those basics then, your rough guide geothermal installation instructions, such as they are, are as follows:

horizontal geothermal installation instructions

Your local climate will affect the exact length of ground loop piping you're going to need, however a decent rule of thumb is to expect something like 70m (about 230 feet) per required kilowatt for straight piping, 10m (about 33 feet) for slinky. Your engineer should have your kilowatt requirement to hand from initial calculations to determine the required capacity of your system.

The exact depth of trench required will, again depend on your local climate and on the rock or soil formation you're installing into. Some rock formations conduct heat better than others. This is something, again, which you should see your installation engineer considering. However, the depth tends to be somewhere around the 2m mark. That's about 6 feet. What you're trying to do is get the best balance between enough depth to tap relaibly constant temepratures with enough heat differential, while at the same time not digging unnecessarily deeply - time (and digging) are money after all.

The heat transfer medium will be a water / anti-freeze mix and, while it shouldn't ever be making contact with the outside environment, it's good if an environmentally-friendly anti-0freeze is selected.

The diameter of pipe used will be in the order of 35mm or so (that's about 1.3 inches). Again, there will be an optimum size somewhere around this value which will produce the best balance between flow capacity and flow velocity, and again, this will depend on the exact spec of your system.

vertical geothermal installation instructions

Pretty much all of the ground work and calculations required for the other closed-loop geothermal / ground source system apply here too. The main difference is that the pipes are, not entirely surprisingly, being laid vertically into deep boreholes instead of being laid out under an extended section of surface. The boreholes themselves are deep - something like 140m (that's 450 feet or so). As with everything else so far, the exact depth will depend on your climate and rock topology. However, the colder your climate, the deeper you should expect to have to go, unless you have some natural ground-heat phenomina going on as found in Scandinavia and such like places. Again, you're looking for a depth which will be sufficiently deep to give you access to a reliably constant heat source of sufficient heat differential, while not boring a lot furhter than required.

You'll be more likely to be using straight pipe as opposed to slinky given the constraints of bore diameter - you may need more than one pipe per bore hole.

open loop geothermal installation instructions

This system differs significantly to the other two in that these systems are open to a suitable water source, whether underground aquifer or well, or surface body of water like a lake. The water is effectively pumped from the source into the target building for heat transfer then discharged back to the outside environment. Similar calculations on required capacities, pipe bore diameters will need to be considered, along with factors like intake and outlet positioning, filtration systems and such like. Obviously, being an open system, it's all the more important that any elements introduced into the system water are non-polluting and environmentally sound.

Thus, while there is no one, definitive set of geothermal installation instructions, there are a number of guidelines and rules of thumb you can employ to ensure your choice of qualified installer is doing a proper job of your installation.

geothermal installation developments

Ground source heating materials boost schools' sustainability - specifinder.com (press release)
28 Jul 2010 at 10:45am
Ground source heating materials boost schools' sustainabilityspecifinder.com (press release)Ynysowen Community Primary School in South Wales has a 14-hole ground source heating system capable of providing 74 kW of heat pump capacity. ...

Grants for Air Source Heat Pumps announced - HeatingandVentilation.net
28 Jul 2010 at 3:08pm
HeatingandVentilation.netGrants for Air Source Heat Pumps announcedHeatingandVentilation.net"As such, we are delighted to extend our successful ground source partnership with Ice Energy into the air source products range and provide further benefit ...

Local firms extend their green expertise - Rochdale Online
28 Jul 2010 at 1:30pm
Local firms extend their green expertiseRochdale OnlineGround source heat pump technology uses heat energy from under the ground to provide heat and/or cooling in a range of building projects. ...

Top of the class for renewable energy performance - Process & Control Today
20 Jul 2010 at 7:32am
Process & Control TodayTop of the class for renewable energy performanceProcess & Control TodayBy exploiting the relatively stable temperatures found under the earth's surface, ground source heat pump systems are able to deliver heating and cooling at ...