How Geothermal Heat Pumps Works Learn how and why a WaterFurnace saves you money

Geothermal heat pumps are not only the most comfortable way to heat and cool, they’re also the most cost effective. They’re versatile enough to excel in almost any home or any environment, and you’ll find geothermal in more than 1 million households across Canada and all 50 U.S. states. They can be scaled for single-family homes to entire college campuses. In fact, WaterFurnace heats and cools their entire 110,000 square-foot headquarters with WaterFurnace equipment. Here are a few reasons why geothermal is one of the fastest growing technologies available for your home.

An Introduction

Geothermal heating and cooling is in step with the times – and with the future. “Green” technologies – which work with the environment instead of against it – continue to gain momentum amid concerns over the skyrocketing cost of fossil fuels and energy conservation. Geothermal technology is proven, reliable and safe. It significantly reduces energy usage and utility bills for homeowners and business owners. Millions of geothermal systems are currently saving money and protecting the environment in all 50 states and around the world. We’ve prepared this booklet to answer questions about how geothermal systems work and how you can benefit from going geothermal.

Geothermal Basics

How does a geothermal heating and cooling system work? Outdoor temperatures fluctuate with the changing seasons but underground temperatures don’t. Four to six feet below the earth’s surface, temperatures remain relatively constant year-round. A geothermal system capitalizes on these constant temperatures to provide “free” energy. In winter, a series of fluid-filled underground pipes called a “loop” absorbs stored heat and carries it indoors. The indoor unit compresses the heat to a higher temperature and distributes it throughout the building. In summer, the system reverses, pulling heat from the building, carrying it through the earth loop and depositing it in the cooler earth.

What makes a Geothermal system different from ordinary systems?

Unlike ordinary systems, geothermal systems don’t burn fossil fuel to generate heat; they simply transfer heat to and from the earth to provide a more efficient, affordable and environmentally friendly method of heating and cooling. Typically, only a small amount of electricity is used to operate the unit’s fan, compressor and pump.

Does a Geothermal system heat and cool?

One thing that makes a geothermal heat pump so versatile is its ability to be a heating and cooling system in one. With a simple flip of a switch on your indoor thermostat, you can change from one mode to another. In the cooling mode, a geothermal heat pump takes heat from indoors and transfers it to the cooler earth through either groundwater or an underground earth loop system. In the heating mode, the process is reversed.

What types of loops are available?

There are two main types: open and closed. he buried pipe, or earth loop, was an important technical advancement in heat pump technology. The idea of burying pipe in the ground to gather heat energy originated in the 1940’s. New heat pump designs and more durable pipe materials have been combined to make geothermal heat pumps the most efficient heating and cooling systems available.

An open loop system uses groundwater from an ordinary well as a heat source. The groundwater is pumped into the heat pump unit where heat is extracted and the water is disposed of in an environmentally safe manner. Because groundwater is a relatively constant temperature year-round, wells are an excellent heat source.

A closed loop system uses a continuous loop of buried polyethylene pipe. The pipe is connected to the indoor heat pump to form a sealed, underground loop through which an environmentally friendly antifreezeand- water solution is circulated. A closed loop system constantly recirculates its heat-transferring solution in pressurized pipe, unlike an open loop system that consumes water from a well. Most closed loops are trenched horizontally in areas adjacent to the building. However, where adequate land is not available, loops are vertically bored. Any area near a home or business with appropriate soil conditions and adequate square footage will work.

Closed loop systems should be installed using only high-density polyethylene pipe. Properly installed, these pipes can outlast the house. They are inert to chemicals normally found in soil and have good heat conducting properties. PVC pipe should never be used.

Closed loop systems also can be vertical. Holes are bored up to 250 feet per ton of heat pump capacity, depending on where you live. U-shaped loops of pipe are inserted in the holes. The holes are then grouted from bottom to top to ensure consistent ground contact with the earth.

Loops can also be installed in ponds if they are deep enough. A minimum of six feet in depth at its lowest level during the year is needed for a pond to be considered. The amount of surface area required depends on the heating and cooling load of the structure. You should opt against using water from a spring, pond, lake or river as a source for an open loop system unless it’s proven to be free of excessive particles and organic matter. They can clog a heat pump system and make it inoperable in a short time.