Ground Source Heat Pumps (GSHP) are the most efficient types of heat pumps, but they can also be the most expensive to install.  Still, for homeowners who can obtain a home equity loan, or who just have the money, investing in a ground source heat pump is a much more sound investment than a new kitchen or living room.  For homes with existing ductwork, not only will this sort of system pay itself off in under 10 years, but it will increase the value of your home as well.  What's more, this increased value to your home is usually exempt from property tax increase.  For information on the approximate cost of installing a geothermal / ground source heat pump, click here.

 

If you're a homeowner living in Westchester County, we can help you determine if your home is right for a GSHP, and then even install it for you if it is.  Please note: in order for us to prepare an accurate quote, we must first determine the heating and cooling loads of your home in order to determine the equipment sizing and loop-field lengths.  We do this through one of our home energy audits .  Our barebones audit will usually allow us to find approximate ranges for these figures, and will usually suffice for the purposes of an estimate; however if you choose to move forward with the installation, our advanced audit will be required for accurate equipment sizing.  Typically, we find it is most cost effective to first reduce the heating and cooling loads of your home via focused air sealing and insulation upgrades prior to the installation of the heat pump.  This not only decreases the installation cost substantially, but also increases the efficiency.  We work with you to bring you not just a heat pump, but a whole house solution. 

 

Types of Configurations

 

One of the trickiest things about installing a ground source heat pump is deciding which configuration will work best with your home.  These systems can extract heat from a series of vertical pipes laid in bore holes drilled by a standard well-drilling rig, or from pipes laid in horizontal trenches laid in the ground.  They can also extract heat directly from your well water, and then disperse it back into the ground.  Each of these configurations can be the cheapest, best solution for one homeowner, while at the same time being completely impractical or too expensive for somebody else.

 

In order to determine whether you might be a viable candidate for a heat pump, and what configuration would be right for you, simply fill out the following form:

 

See below for an explanation of what this means:

Open-Loop	These are most commonly used in Long Island due to the shallow depth of acceptable ground water.  They work by pumping ground water directly through the heat exchanger, and then returning the water to the ground via one or two diffuser wells. Of all the systems listed, these are the cheapest to install and operate at the highest efficiencies.  However, impurities in the water can cause premature system failure, so groundwater tests must first be conducted to determine whether or not your home is compatible. Another important consideration is that aquifers with acceptable quantities of water may not be as readily accessible as you might think.  While the water used to heat your home is returned to the ground after use, the diffusion well may not be connected to the supply well.  Therefore, the system may need to reverse flow in order to maintain adequate levels of water in both reservoirs. A number of installers steer clear of open loop systems because of the complications associated with them.  Still, for homeowners with easy access to clean water, such as residents throughout Long Island, these systems are an easy choice.
Vertical Closed Loop	Vertical Closed Loop systems are the most commonly installed systems in Westchester County.  Here, we have fairly rocky soil with scattered aquifers, many of which are filled with hard water.  This means that both open-loop and horizontal closed loop systems can present challenges.  A closed loop system is therefore a much safer choice for most homeowners, and while it may be more expensive due to drilling costs, complications are far less likely to affect the quoted price.
Horizontal Closed Loop (Slinky)	Horizontal Closed Loop Systems are installed in a number of different ways.  The first, and most common for larger commercial jobs, is by excavating out a large rectangular plot of land and laying down a layer of coiled high density polyethylene pipe (known as "slinkies") which is in turn connected to the heat exchanger, and then backfilling.   These systems may also be installed by digging a series of very narrow trenches (only a few inches wide) using a miniature chain excavator, a machine similar to a chain saw, but with buckets instead of teeth.  Loops of pipe are then dropped into the trench and the trench is backfilled.  This sort of system cannot work in Westchester because excavators of this type have extreme difficulty with rocks. The third approach for installing horizontal closed loop systems is to dig trenches using a standard excavator.  Loops of pipe are laid flat on the bottom of the trench, and it is backfilled.  Systems of this sort can be installed for residences in Westchester, but a substantial amount of open land is required to that the trenches can be bent around large subterranean rock formations.  Due to the colder climate of the area, the trenches should also be deeper than they would be in other parts of the county, which means that a larger excavator should be used.
Pond (or water body)	A number of approaches may be used to extract heat from bodies of water such as ponds, lakes, rivers, and streams.  These sorts of systems are far and away the cheapest to install, and their efficiencies are only slightly lower than traditional heat pumps.
Direct Expansion (DX)	Direct Expansion (DX) systems (also sometimes given the misnomer "Direct Exchange") work differently than traditional Ground Source Heat Pumps (GSHPs).  In a traditional GSHP, heat is extracted either directly from the ground water (open loop) or from a glycol solution that pumps through closed loops of high density polyethylene pipe (HDPE) that is heated and cooled by the ground.  The extraction process utilizes an intermediate compressor loop to "pump" the heat from either the water or the glycol into the air that will then circulate throughout the home.  There are therefore three separate "loops" involved in the process; the ground loop, the refrigerant / compressor loop, and the loop that delivers the heat to the home, usually via air or hydronic (water) circulation. A DX system, on the other hand, only has two loops.  This increases its efficiency, but it comes at a cost.  In these systems, the ground loop and the compressor loop are the same.  They work by pumping refrigerant through the ground loop which is directly connected to the compressor.  They use copper pipe for the ground loops instead of polyethylene.  Copper pipe is a better conductor of heat than polyethylene, and it's somewhat cheaper to install because less excavation is required.  However, the same concepts that give these systems their economic advantages can also make them environmentally hazardous, and potentially much more expensive in the long run.  They're a much newer technology and so they lack the time proven track record of traditional heat pumps.  For these reasons, we at Varna Energy Solutions do not install DX systems.  Other companies in the area do, and we have yet to hear about any problems with their installations, but currently do not feel comfortable with the theoretical long term risks.  For a longer explanation, click here.
Standing Water Column	A standing water column heat pump is sort of mix between an open loop system and a closed loop vertical system.  A single deep hole is drilled into the rock beneath the building.  The hole leading down to the rock is cased to the rock, but a central pipe is installed that leads all the way to the bottom.  Water is then pumped through the outer section of the pipe down into the ground where it comes in contact and is warmed by the bedrock and then returned via the central pipe.  Rock is slightly porous, so some of the water (about 20%) is lost during this cycle.  This water is replaced by new water further down the well.  For this reason, when installing a standing column system, not only must there be sufficient natural water flow into the well to replace that which is lost during the cycle, but the ground water must also be pure (i.e. not hard) so it won't destroy the pump over time.  It therefore can be a bit of a gamble installing one of these unless there are sufficient drill logs for the area to confirm both water quality and quantity at the site.