Archive for the ‘News’ Category

Muskoka Geothermal groundsource or watersource Performance Questions

Friday, February 3rd, 2012

Performance Questions

Details How efficient is a geoexchange system?

The performance of the heat pump unit is rated by its ‘Coefficient of Performance’, which calculates how much energy is required to transfer heat into a building. Units are tested under the CSA C446, ARI 320, ARI 325 or ISO 13126 standards. In Canada, units cannot be sold if they rate below 2.8 CoP and many units achieve 3.5 or above. If the CoP is 3.5, a system requires 1 kW of electrical energy to transfer and deliver 3,500 W of space heat; this is equivalent to a combustion furnace with an efficiency of 380 percent.

Details How long will the loop pipe last?

The pipe is high-density polyethylene. Most suppliers provide a warranty of 25 years or more, and the pipe will usually last longer.

Details What factors will affect the performance of a geoexchange system?

Common problems for degradation of output in a well-designed system include dirty air filters (fixed by cleaning), air trapped in the ground loop (requiring purging) and declining anti-freeze level (fixed by adding more to the loop). Human error includes mis-setting the thermostat while natural problems include dropping water table or increasing mineral content in the water.

Details Is a geoexchange system more comfortable than a conventional furnace?

A heat pump moves a large volume of warm air throughout a building, but it is at a lower temperature than a combustion furnace, resulting in an even and steady delivery with no draughts. The lack of combustion and higher air circulation of a geoexchange system results in less indoor air contamination and lower pollution levels, as well as reduced humidity build-up.

Details What happens when the outdoor temperature becomes very cold?

Although the outdoor ambient temperature can drop significantly and quickly, the temperature of the ground below the frost line remains constant and it is from this level that a geoexchange system extracts heat. In the worst case scenario where the outdoor temperature drops for a prolonged period and there is an extraordinarily high demand for heat, the supplemental heating unit on the geoexchange heat pump will provide the difference in heat.

Details Does the quality or quantity of water have any bearing on performance?

Water that comes directly from a lake or a well must meet certain levels for temperature and flow rate, and must contain few minerals. The CSA standard requires an official water well log to ensure that the yield is sustainable, and an analysis should be done to determine if the water contains any chemicals or metals that could damage the heat exchanger or other component.

Details Can a geoexchange system be diagnosed by long distance?

Some manufacturers have incorporated electronic measurements to provide diagnostic capability over the telephone. In some cases, this allows the system to be re-set without a service call.

Details How safe is a geoexchange system?

A geoexchange system is considered to be one of the safest heating/cooling systems available. No combustible fuels are used, which eliminates any chance of explosion, and it also reduces concerns over indoor air quality (IAQ). There are no outside components that can be tampered with or vandalized.

Details What are the options for water heating?

A geoexchange system heats domestic water with a demand unit or a de-superheater. The former gives priority to water heating over space heating, while a de-superheater will heat water only after space heating has been accomplished. The difference depends on the lifestyle of the occupants.

Details How durable is the pipe in the ground loop?

The CSA standard allows only high-density polyethylene pipe, with the three most common diameters being 0.75″, 1.0″ and 1.25″. Sections of pipe are heat fused and many suppliers offer a warranty of 25 years. The resin in this pipe is the same used in the pipe used to transport natural gas. This plastic does not degrade under sunlight and is warranteed not to fail.

Details Does a geoexchange system come complete with all components?

Most units include all pumps and controls, but it may be the responsibility of the contractor to obtain some individual components. All non-packaged components must be compatible with the heat pump unit, and written documents should demonstrate that the manufacturer allows the components to be used and that their use will not interfere with warranty coverage.

Details Are geoexchange contractors certified?

A number of manufacturers offer training for their authorized contractors that is specific to that brand but, as of 2002, there is no certification program in Canada. A programme was offered by the Canadian Earth Energy Association (the predecessor of the Earth Energy Society) until 1993. There is a program offered by the International Ground Source Heat Pump Association and the Geothermal Heat Pump Consortium in the United States. There are a number of related certifications (for heat loss analysis, ductwork installation, etc) offered by the Heating, Refrigeration & Air-conditioning Institute of Canada, among others.

Details Where does water from an open-loop system go?

There are environmental regulations, which govern how the water used in an open-loop system can be returned to the ground. A return well is acceptable, as long as the water is returned to the same aquifer or level of water table. A discharge pit is also acceptable, as long as local regulations and conditions are considered in the design.

Details Are all GeoExchange pipes straight?

There are two coiled loops on the market, called the Slinkey and the Svec Spiral, which require less trenching and reduce installation costs. The installation of coiled pipe is more demanding than straight pipe, and back-filling must be done properly.

Details How is the CoP efficiency rating determined?

Units are tested under laboratory conditions, with a set temperature for the entering water. The total heat output and the electricity required to operate the entire system are the two variables used to determine the CoP rating for each unit.

Details What are the environmental benefits of geoexchange?

Due to the use of solar energy and the high efficiency of the transfer technology (the heat pump), a geoexchange system can greatly reduce emissions of CO2 and other greenhouse gas emission compared with combustion furnaces. The lack of combustion naturally means a chimney is not needed.

Details Is there a lot of noise from a geoexchange system?

The compressor, pump and blower are all sound-insulated. The CSA standard requires a heat pump to be placed on top of an acoustical air pad to eliminate vibration noise and there must be sound dampeners where the heat pump connects to the ductwork. The system is one of the quietest options on the market.

Details Can a large number of geoexchange systems create ecological problems?

Each system is designed to ensure sufficient heat from the property in which it operates, and there is no potential to “freeze the globe” or to disturb natural habitats or ecosystems. Systems use renewable energy to heat a building, and benefits to the environment increase with the number of units added to a geoexchange system, when compared with conventional fuel-based heating unit

Posted in Choosing a Contractor, News | No Comments »

David Suzuki on Geothermal heating and cooling your Muskoka home or cottage: Geothermal WaterFurnace Heatpumps are the way to go.

Wednesday, February 1st, 2012

Geothermal heat pumps are one of the cheapest and most reliable ways to heat

and cool most buildings today.

Geothermal pumps draw energy from the earth, using a series of underground

pipes. In winter, these systems bring the earth’s warmth up into a building, concentrate

it, and distribute it using heat pumps and ventilation systems. In summer, they

work in reverse, extracting heat from inside to be discharged into the cooler earth.

The earth itself supplies the renewable thermal energy, and the systems run with

almost no pollution or greenhouse gas emissions.

Smart Generation shows geothermal pumps can be widely used to provide heating

and cooling for all new residential and commercial buildings in Ontario. By 2010,

Ontario can install 125,000 residential geothermal pumps, saving the equivalent of

7.7 petajoules per year. By 2020, the province can install 341,000 geothermal systems

in new homes, saving the equivalent of 21 petajoules per year (the equivalent of about

750,000 tonnes of coal, or 3.7 million barrels of oil).

Ontario can follow the example set by Manitoba Hydro, which has become a

Canadian leader in geothermal heat pumps. Manitoba Hydro currently offers

homeowners a loan up to $15,000 to install a geothermal heat pump when building

a new home or replacing an old heating system. According to Manitoba Hydro,

installing 1,000 geothermal heat pumps in homes generates $15 million in construction-

related activity.

The City of Winnipeg is developing plans for a 100 per cent geothermal new

subdivision. If built, it would be the largest geothermal housing development in

Canada.

In Ontario, about 8,500 homes and 500 institutional and commercial buildings

are currently using geothermal systems. These systems offset the need for

electricity-hogging air conditioners and heating systems based on electricity

or natural gas.

Geothermal

heat pumps

Manitoba Hydro is leading Canada

in supporting geothermal heat

pumps for a variety of applications,

including homes and other buildings

such as recreation centres.

According to Manitoba Hydro,

the installation of 1,000 geothermal

heat pumps in homes generates

$15 million in construction-related

activity.

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

SMART GENERATION: POWERING ONTARIO WITH RENEWABLE ENERGY 11

Economic benefits

The cost to install a geothermal system that can provide 100 per cent of heating and

cooling is about $20,000 for a new 2,000 square foot home in a Toronto subdivision.

The energy savings achieved by installing a geothermal heat pump are considerable.

Annual heating costs are $400, markedly lower compared to $1,000 for electric

furnace or electric baseboards, $1,250 for a gas furnace or $1,600 for a conventional

oil furnace.

Installing 125,000 home geothermal systems could result in 18,750 jobs by 2007.

By 2020, the installation of 341,000 geothermal pumps could create up to

51,150 jobs.

Fast facts

Ontario can use geothermal

energy for 20 per cent of the air

conditioning and water heating

load in all provincial and municipal

buildings by 2010. This level

should rise to 50 per cent by 2020.

Geothermal energy can be widely

used to provide heating and

cooling for all new residential and

commercial buildings in Ontario.

By 2010, Ontario could install

125,000 residential geothermal

systems that would provide

heating and cooling, saving

the equivalent of 2.1 million MWh

per year.

Posted in Choosing a Contractor, Equipment & Supplies, Heating and Cooling, News | 1 Comment »

Carbon Monoxide: How do I keep it out of my home?

Tuesday, January 31st, 2012

Keep Carbon Monoxide Out of Your Home

Carbon monoxide (CO) is a harmful gas that has no colour, smell or taste.

CO forms whenever you burn fuel such as propane, natural gas, gasoline, oil, coal and wood. It is also contained in second-hand smoke. If furnaces, fireplaces, gas stoves or water heaters are improperly installed, or if they malfunction, they can release CO into your home.

What Are the Health Effects?

CO can cause health problems before people even notice that it is present.

When you breathe in CO, it reduces your body’s ability to carry oxygen in the blood.

Even at low levels of exposure, CO can cause headaches and make you feel tired. The health effects at higher levels can be much more serious and can even lead to death.

How do I know if I Have a Problem?

CO can be detected only with a carbon monoxide detector.

What Can I Do?

Maintenance is the key!
- There is no substitute for good maintenance of fuel-burning appliances because CO detectors may not detect low levels of CO that can, over time, have effects on your health.
- Make sure appliances such as furnaces, fireplaces, gas stoves and water heaters are well maintained and inspected by a professional at least once a year.
Get a CO detector!
- Put at least one carbon monoxide (CO) detector in your home. A smoke alarm helps protect against fires, but will not warn you of potentially harmful carbon monoxide in your home. It is important that you have a carbon monoxide detector in your home as well as a smoke alarm.
- Install a Canadian Standards Association (CSA) certified CO detector with an audible alarm to warn you of high CO concentrations in your home. The most important place to install a detector is in hallways, outside of sleeping areas. Make sure to follow the manufacturer’s suggestions on how to install and use the detector, and when it needs to be replaced. You can use a marker to remind yourself when it was installed and when it should be replaced.
Leave it outside!
- Never use a barbecue indoors.
- Don’t use kerosene or oil space heaters or lamps in enclosed areas unless they’re specifically designed for indoor use.
No idling indoors!
- Don’t let vehicles idle in the garage, even when the garage door is open.
- Never run gas-powered lawnmowers, trimmers, snow blowers or other machines in the garage.
- Keep the door between your house and the garage closed.

INSTALL A HEAT RECOVERY VENTILATOR

Posted in Equipment & Supplies, Heating and Cooling, News, Uncategorized | No Comments »

What qustions should I be asking about my Muskoka geothermal ground source or water source design and installation?

Monday, January 30th, 2012

Installation Questions

Details How to size a geothermal heatpump for residential building?

Have a qualified CGC and HRAI contractor takes responsibility for the size. Such as www.gravenhurstplumbing.com

Details How deep should a loop be?

The Canadian Standards Association (CSA) C448 standard requires that horizontal loops be buried at least 4 feet below surface. The deeper the depth the better, as thermal stability increases with depth. Many provinces demand the use of trench scaffolding if depths exceed 6 feet, which imposes a cost. Vertical boreholes have no limits on depth, although an average depth is 100-200 feet.

Details Is there a national / local standard to govern the installation of a geoexchange system?

As of March 2002, both residential and commercial installations are covered under the Canada Standards Association (CSA) C448. We are not aware of any provincial regulations affecting Geoexchange installation, though some municipalities or other regulatory agencies may have guidelines or rules pertaining to the installation of systems. CGC members should be informed and current on all relevant standards and regulations, though as always, the burden of information falls on the consumer. We therefore recommend consumers raise the question with your local installer and local government officials, until you are satisfied that all necessary standards and regulations have been met.

Details How far apart should trenches and vertical boreholes be spaced?

Trenches are usually spaced 8-10 feet apart, while boreholes are spaced 10-15 feet apart.

Details Can someone other than the contractor install the ground loop?

Most contractors prefer to retain control over the entire job to ensure compatibility of all sections, but the digging of the horizontal trench (and backfilling) is one area that could reduce costs if done under the guidance and direction of the installing contractor.

Details Can a homeowner install a geoexchange system?

It is recommended that a qualified and certified contractor be used to design and install the system. If a homeowner wants to save money and has access to a backhoe, the contractor may provide details on where to trench on the property, and when to backfill after the loop is installed.

Details How deep should the vertical borehole be drilled?

Deeper is generally better, but there can be technical constraints. Most residential boreholes are 75-100 feet, but some can be as deep as 1000 feet depending on soil properties, heating requirements, and other factors.

Details How deep should the ground loop be installed?

The CSA C448 standard directs that the minimum depth is 4 feet; the former 445 standard required 2 feet. The objective is to install the loop as far below the frost line as possible. Many provinces require safety measures when a trench is more than six feet deep, so most contractors do not exceed that depth in order to reduce costs.

Details Are there any concerns with joining sections of underground pipe?

The high-density polyethylene pipe is socket fused (basically, melted together with a high temperature tool), which makes the joined plastic section more solid than the original resin. If done by a certified fusion contractor, there is virtually no chance of breakage or separation under normal conditions.

Details How many pipes should be installed in a trench?

From one to six, depending on design considerations and the thermal characteristics of the soil.

Details What spacing is required for the ground loop?

Each pipe extracts heat from the nearby soil, so separation should be as wide as possible. The CSA standard demands at least 10 feet between sections of loop, which can be reduced under certain conditions.

Details Does a geoexchange system use a setback thermostat?

A geoexchange system relies on a constant, low level of temperature for the building, and any sudden increase in heat demand will cause the supplemental backup heating unit to activate. Setback thermostats are not recommended for use with a geoexchange system.

Details Is it possible to make a mistake when installing the ground loop?

It is unlikely that a certified loop installer would make any mistake since he/she is trained to fuse sections of loop. The CSA standard requires that a system be tested to a pressure above normal operating levels, to determine if there are any leaks or problems which can be corrected immediately.

Details Is there a concern with poor-quality water in an open-loop system?

In a closed-loop system, the water must be of good quality and meet the specifications of the heat pump manufacturer and the supplier of the anti-freeze solution with which it is mixed. In an open-loop system, some chemicals and minerals in the water may not be compatible with the heat exchanger. An analysis of the water should be performed before purchase to determine which model of exchanger is required. If the water content changes over time, this may have a detrimental impact on the system.

Details Can a geoexchange system be added to a fossil fuel furnace?

A dual system can be added to an existing furnace to provide a dual-fuel heating system, where the heat pump is the main source of heating and the combustion furnace provides the supplemental heat.

Details Is a geoexchange system difficult to install?

The ground loop can be difficult to install, depending on rocks, physical obstructions and topography. The interior heat pump is easy to install, and can be located in areas without proper ventilation (there is no combustion, so no need for exhaust). Most units are easy to install, especially when they are replacing another forced-air system. The air distribution may be difficult in a retrofit installation.

Details Will a geoexchange loop affect a lawn or landscape?

The only impact will be a period of settling for soil that is placed back in the trench. This visual evidence takes one year to settle.

Details Can a geoexchange system be located in a septic bed to take advantage of the heat?

The CSA standard specifically bans locating a ground loop near septic systems to avoid retarding the microbial action to decompose sewage. Grey water from the building can be used in some situations, if that collection unit is separate from the septic system.

Details What heat transfer fluids are permitted?

The anti-freeze that is used in a closed-loop system must be approved by provincial authorities and acceptable to the heat pump manufacturer. Methanol and denatured ethanol are the most common fluids used (methanol is not approved for use in Ontario). The fluid must be mixed with water in accordance with instructions, usually on a 4:1 ratio of water-to-chemical.

Details Can I install a ground heat exchanger myself?

It is not recommended. In addition to thermal fusion of the pipe, drilling and trenching are procedures best handled by licensed professionals. Non-professional installations may result in less than optimum performance, which could cancel out anticipated savings. Also, warranties are usually void if a non-authorized dealer installs the system.

Details Will trees or plants affect ground temperature or the efficiency of a geoexchange system, of vice-versa?

No. Systems are installed away from trees to avoid damage to root systems when digging the trench.

Details How long does an installation take?

Depending on soil conditions and the length and depth of pipe, a typical residential system can be installed in two days. Commercial systems depend greatly on geography and system size for accurate estimation.

Details What laws apply to open-loop installations?

The CSA C448 standard contains a number of requirements to ensure that an open-loop unit does not abuse the increasingly valuable water resource.

Details Does the capacity of electrical service need to be increased with the addition of a heat pump?

A contractor can advise if an upgrade is required to accommodate the additional electricity required.

Posted in Choosing a Contractor, Heating and Cooling, News | No Comments »

Why every home should have a Heat Recovery Ventilator

Thursday, January 26th, 2012

Feds look into Canada’s killer homes

Every year, 2,000 die from radon exposure. Is it in your home?

by Michael Friscolanti on Monday, February 9, 2009 12:49pm - 9 Comments

Your life savings are vanishing, your job is in jeopardy, and the repo man has already visited some of your friends and relatives. Now here’s the really bad news: your beloved home—the one you’re desperately trying to save from foreclosure—may actually be killing you (and not because of the mortgage payments).

The culprit? Radon: a tasteless, odourless, invisible gas that lurks in cellars and crawl spaces and is the second-leading cause of lung cancer, next to smoking. Every year, up to 2,000 Canadians die a premature death because their homes—unbeknownst to them —are loaded with tiny radioactive particles.

This nasty little gas is hardly new (scientists have been studying its fatal side-effects for more than a century), but the federal government is suddenly anxious to find out which neighbourhoods are most at risk. Over the next two years, Health Canada plans to spend almost $1 million testing 18,000 randomly chosen homes, with the end result being an online “radon potential map” that pinpoints possible danger zones. “Radon is the largest source of radiation exposure for most Canadians,” says Jack Cornett, a ministry spokesman. “But we are concerned that there is a real lack of awareness about it.”

Here’s what Health Canada wants you to know: first, don’t panic. Radon is a naturally occurring gas released by uranium decay in the soil, and the experts believe that only 2.5 per cent of all homes contain “unsafe” levels (more than 200 becquerels per cubic metre). Second, if you’re still nervous, conduct your own test. Do-it-yourself radon kits cost as little as $50 at the local hardware store. Third, seal all the cracks in your basement floor. Radon loves to seep through those crevices.

Oh, and don’t smoke cigarettes. Apparently that causes lung cancer, too. MOST IMPORTANT: INSTALL A HRV!! SEE:http://www.lifebreath.com/en/consumer/products/residential/hrv/

Posted in Choosing a Contractor, Heating and Cooling, News | No Comments »

What is a hybrid system and how can it help heat my Muskoka home?

Wednesday, January 25th, 2012

Hybrid System Logo Most consumers are familiar with the term “hybrid” in reference to cars that combine electric and gas fuel for better performance. Long before dual-fuel cars were on the market, a consumer could get a dual-fuel heating and cooling system. A central hybrid comfort system uses gas and electric heat to reduce heating expenses in the winter while also keeping your home comfortable. It is one of the most economical type of system that does not compromise comfort.

Posted in Choosing a Contractor, Equipment & Supplies, Heating and Cooling, News, Uncategorized | No Comments »

What makes a hybrid system different?

Tuesday, January 24th, 2012

Hybrid system logo What makes a

hybrid system different?

Since it is a rare task to replace your central heating and cooling system, let’s start with some basic knowledge about a typical set-up. The most common heating and cooling system set-up is a gas furnace with a coil and an electric air conditioner. This is a ‘split system’, which means the coil is located inside the home with the furnace and the rest of the cooling component (the AC) is outside…hence the system is split between locations, giving its name. The air conditioner uses the furnace’s blower to distribute cool air when it’s hot outside. The furnace heats the home with a fossil fuel (i.e. natural gas, propane or oil) when it’s cold outside. The hybrid is different from a typical system because it provides two heat sources: electric heat and a fossil fuel. In many locations, it is more economical to heat the home with the electric heat pump, at least until the outdoor temperature falls below a specific temperature point. Below that temperature point, the furnace heats the home more economically.

Posted in Choosing a Contractor, Equipment & Supplies, Heating and Cooling, News | No Comments »

What are the main design criteria to design my Muskoka geothermal system

Monday, January 23rd, 2012

GeoExchange Systems Design

Details What size of heat pump is required for a given building?

A heat loss – heat load assessment will determine how much heat the building requires. The installed heat pump and supplementary backup unit must meet this load, subject to the conditions in the CSA standard. The quantity of loop must be consistent with the size of the heat pump. On average, a 4-ton unit will be sufficient for a 1,700-ft² home.

Details Is the geoexchange system designed to provide 100 percent of building heat and water heating?

A heat loss calculation will determine how much heat is required for both applications, but most systems are sized to meet less than the full design load and rely on an electric backup heater to provide supplemental heat on very cold mornings during the winter. In all cases, full cooling load can be met by a system.

Is there a national or local standard for the design of a geoexchange system?
Proper design is covered under national CSA standards C445 (residential) and C447 (commercial). As of March 2002, both applications will be covered under CSA C448. We are not aware of any provincial regulations, while some municipalities or other regulatory agencies may have guidelines or rules pertaining to the professional installation of systems.

Details Is there a national or local standard for the design of a geoexchange system?

Proper design is covered under national CSA standards C445 (residential) and C447 (commercial). As of March 2002, both applications will be covered under CSA C448. We are not aware of any provincial regulations, while some municipalities or other regulatory agencies may have guidelines or rules pertaining to the professional installation of systems.

Details What is an open loop?

One pipe is used to take water directly from a lake or river, or an underground well or aquifer. The water is circulated through the heat pump to extract the heat, and a second pipe is used to return the water to the same source. Standards dictate that the amount of water extracted cannot impact negatively on the ecosystem, and consideration must be given to discharge areas to avoid impacts (e.g.: if slightly warmer water is discharged into a lake during summer, the discharge should not be located near sensitive aquatic life).

Details What is a lake loop or river loop?

The pipe is anchored to the bottom of a water body of sufficient depth, and extracts heat directly from the water. The pipe must be weighted to avoid shifting, and must be protected at the point of entry into the lake to avoid being severed by ice movement in the spring. The position is determined to avoid damage from boat anchors. The amount of heat extracted from the water is so low and diffuse that there is no ecological damage to marine life or aquatic systems, even in the immediate vicinity of the loop.

Details What is a vertical closed loop?

A drill is used to bore a cavity, into which a section of looped pipe is inserted and sealed according to provincial regulation. This configuration is the most efficient, since it extracts both solar heat from near-surface soil, as well as magmatic heat from deeper areas. This option is used when surface property is limited.

Details What is a horizontal closed loop?

A trench of at least 4 feet depth is dug. At the bottom, the high-density polyethylene pipe is placed and the trench is carefully back-filled to avoid air pockets or damage from sharp rocks. There can be from one to six pipes placed in each section of trench, subject to appropriate spacing to allow for thermal separation. The pipe does not have to be perfectly level.

Details Why is there lack of consensus over the issue of system sizing?

Most consumers will receive excellent performance and savings with a geoexchange unit that is designed to provide 70-75% of the total heat loss for the building. When ambient temperatures are above the design balance point, the geoexchange unit will provide all heating required; only when outdoor temperatures drop below that point does the geoexchange unit require supplemental heat from an electric resistance-heating element inside the unit. Most outdoor winter temperatures are above the balance point, and the geoexchange system can provide 95% of the load if the unit is sized to 70%. Some dealers prefer to install a system that meets 100% of heat loss; this eliminates the need for supplemental heating but increases the cost of installation (more pipe is required).

Details What is the difference between a closed loop and an open loop?

A closed loop is a continuous pipe that circulates a fluid (often with an antifreeze mixture) to extract heat from the surrounding soil or water. An open loop is, essentially, two pipes: one to suck in water that is moved through the heat pump to transfer heat, the other to take the cooled water and discharge it to the appropriate location, usually downstream from the first pipe.

Details Is ductwork for air required?

A geoexchange system can heat either air or water. If air, ductwork is required to circulate the warmed air throughout the building. Due to the low temperature rise of a geoexchange system, the volume of circulated air is higher than a combustion furnace and, therefore, the ductwork must have a higher capacity in cubic feet per minute.

Details Is there any difference between a ground loop and a water loop?

Both loops extract heat from the surrounding earth (soil or water) for transfer into the heat pump. Temperature changes in water temperature can be more dramatic than changes in soil temperature (e.g.: if your water loop were located near a glacial stream) and water levels are more prone to change (e.g.: drought conditions).

Details What are the options if there is insufficient room for a horizontal loop?

The loop can be installed in a vertical borehole(s). An open-loop system may be possible if there is sufficient water. The use of coiled loop pipe or numerous pipes in the same trench may be a feasible option.

Details What are the components of a geoexchange system?

There are three basic sections: energy supply comes from the ground loop (or vertical or lake loop); the conversion of heat occurs in the heat pump and compressor; and the warmed energy is delivered through the circulation system (ductwork or in-floor radiant heating).

Details Can a geoexchange system heat a building without supplemental heat?

A system can be designed to provide 100% of heating needs on the coldest days in northern Canada, but the cost to install such a system would be excessive. A system designed to provide 70% of a calculated heat load is the optimal sizing if there is a supplemental heating element, but the history of earth energy systems includes past errors in heat loss calculating and, consequently, some systems have been installed under-sized. The new CSA standard for installation (C448) has been revised to overcome this deficiency.

Details How long should the buried ground loop be?

The length of pipe depends on two factors: the amount of heat required in the building (the more heat required, the larger the heat pump and the longer the loop must be) and the thermal transfer characteristics of the soil (dry light soil with entrained air can require three times the amount of loop to provide the same heat as wet, packed soil). Design software will calculate the amount of pipe for a specific site. An industry rule of thumb is that an average home requires a four-ton unit, which requires 400-500 feet of horizontal loop or 300-350 feet of vertical borehole for each ton (up to six pipes can be installed in a horizontal trench if spaced properly).

Details Are there advantages of an open-loop system over a closed-loop system?

Open-loop units usually are less expensive to install (no need for trenching or drilling) and are more efficient (the heat in the supply water is transferred without the need for antifreeze). Closed-loop units offer more security of supply (less chance of constriction of the water supply) and have no environmental impact. Often, closed loops operate at a lower cost than open systems due to lower pumping power required.

Details What is the link between size of heat pump and length of loop?

The higher the heat load (demand for heat), the larger the heat pumps. The larger the heat pump, the longer the loop required.

Details How much power does a geoexchange system consume?

The system requires electricity to operate the loop pump, the compressor and the circulating fan (in forced air distribution). It also uses electricity in the backup mode to deliver sufficient heat on very cold days, and requires power throughout the year to operate the water-heating component. The amount of power used will depend on the size of the unit, operating times and sizing considerations, but an average residential unit would require 11,000 kWh per year, which represents an annual cost of $935 (based on 2001 retail prices).

Details Can any pond be used as the heat source?

The body of water must be large enough to contain sufficient latent heat to meet the demand of the building. The larger and deeper the better; stagnant or glacier-fed bodies are not feasible.

Details Can a geoexchange system be used for radiant floors or hydronic heat?

The heat pump can produce water that is hot enough for use in these applications. In most cases, it is not warm enough to be used in old-style under-the-window radiator systems.

Details Where can the ground loop be located?

The CSA standard does not allow pipe to be placed near septic tanks or hydro lines, and must be a minimum distance from neighbouring property lines.

Details How does heat circulate if the building has no ductwork?

Without ducts, the only option is to circulate heated water through a radiant in-floor configuration, or small fan coil units.

Details How much groundwater does an open-loop system require to operate?

Depending on the heat load of the building, most units require 8 to 12 gallons per minute of water; more if the unit is heating potable / service water at the same time.

Details If the entering water temperature drops, what is the impact on the geoexchange system?

Lower water temperature (either direct from a lake/well or cooler fluid returning in a closed loop) reduces the available heat that can be transferred to the building; i.e.: the building gets colder. If the entering water temperature drops below a set temperature, the geoexchange system will shut down.

Details What should be done with discharge water from an open-loop system?

The CSA standard and provincial / local regulations require that the water be returned to source after passing through the heat pump. The system removes only a small amount of heat, so the water discharged is not classified as sewage. Care must be exercised to ensure that open-loop systems protect the environment to the greatest degree possible and comply with all laws, standards and regulations.

Details Will my existing ductwork function with this system?

Your contractor can determine the ductwork requirements for your system and identify if modifications are needed.

Details Will baseboards work to circulate heat?

Baseboards usually can only conduct electricity. A geoexchange system requires either ductwork to circulate warm air or radiant in-floor coils to circulate warm water.

Details Does a geoexchange system require additional insulation in the building?

The lower the demand for heat, the smaller the heat pump and the lower the installed cost. Insulation, along with any energy management or conservation technique, is always the best first step in any heating system.

Details What will cause a geoexchange system to fail?

The main reason for system failure is under-sizing in design, which means that the building requires more heat than the geoexchange system can reasonably provide, and the resulting strain causes a component to fail.

Details Why is there supplemental heating?

To reduce installation costs and provide better performance, an electric resistance heating element is included in unit to boost the heat during extremely cold temperatures. A fossil fuel furnace can also be integrated

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What is Geothermal Energy?

Friday, January 20th, 2012

What is Geothermal Energy?

The sun has always provided heat for the earth. Its energy warms the earth directly, but also indirectly. Its heat evaporates water from the lakes and streams, which eventually falls back to earth and filters into the ground. A few metres of surface soil insulate the earth and ground water below. The warm earth and ground water below the surface provide a free, renewable source of energy for as long as the sun continues to shine. The earth under an average residential lot can easily provide enough free energy to heat and cool the home built on it.

The free energy has only to be moved from the ground into your home. This is done either by pumping water from a well (open loop) or by pumping a heat transfer fluid through a horizontal or vertical circuit of underground piping (closed loop). The fluid, called the heat transfer fluid, absorbs the heat in the ground water or soil and transfers it to the heat pump. The heat absorbed by the fluid from the solar-heated ground is extracted from it by the heat pump, and the now-chilled fluid is circulated through a heat exchanger over and over again to extract more heat from the earth.

If your home is located near a suitable pond or lake, you can use a Geo- Exchange System (GXS) to draw on this excellent source of free energy.

Burying a loop in the ground around your home is like owning your own oil well, but instead of pumping oil from an underground pool and burning it to create heat (and greenhouse gases), you tap into clean energy that will be there for as long as there is a sun

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