Frequently-Asked Questions

What are mechanical HVAC systems?

Mechanical HVAC systems heat, ventilate, and air-condition a building. Ventilation supplies outside air to improve indoor air quality. Heating and cooling controls the comfort of a space by adjusting temperature and humidity. What is comfortable will depend on the use of the building. Different temperature and humidity levels are required if you are playing hockey at an indoor ice rink versus standing on the deck of an indoor swimming pool or relaxing on a couch in a residential dwelling. A poorly functioning HVAC system can contribute to indoor air quality concerns, higher energy consumption, and potentially uncomfortable surroundings.

What size of building requires a professional engineer for HVAC and geothermal systems?

In general, a professional engineer is needed when designing an HVAC system for buildings exceeding 600 m2 (6,458 ft2) or densely occupied structures that are taller than three storeys (such as residential, business, and retail establishments). Medium and low hazard industrial (Division 2 & 3) buildings also require engineering consulting.

For geothermal systems, the design of the ground heat exchanger (vertical, horizontal, pond, or open loop using groundwater) requires a professional engineer if the conditioned floor space is greater than 1,400 m2 (15,070 ft2).

How long will my HVAC system last?

HVAC equipment (like boilers, furnaces, and air conditioners) typically lasts for about 20 years. If well maintained, the equipment can function longer. But if exposed to outside conditions and/or if poorly maintained, it will need replacing significantly sooner. The accompanying system that connects the equipment – HVAC ductwork, distribution piping, and radiant PEX piping – will generally stand up much longer than 20 years. Geothermal piping is guaranteed for 50 years, but can last for generations.

What is Energy Modelling or Building Modelling?

Using sophisticated modelling software, such as Trane Trace 700, a simulation of your building’s hourly energy consumption and loads over a year is generated to test the implications of design decisions before your building is constructed. Variables such as the orientation of the building (relative to the sun), window and door choices, R-value of insulation, air tightness, lighting, occupancy, electrical equipment, HVAC system type, as well as the local climate are taken into account.

The art to this science is in processing the right information in the model and correctly interpreting the data provided by the simulation to ensure its reliability. As a specialist in geothermal and other renewable technologies with more than ten years’ experience in the field, Roger Taliotis can help you make solid decisions on a long-lasting, energy efficient HVAC system for your building.

Are larger heating and cooling systems more efficient?

The old way of thinking was that “bigger is better.” To ensure heating and cooling demands were met, huge mechanical systems were installed to cover imprecise load calculations performed by rules of thumb or using simple spreadsheets. In the age of cheap energy, consequences were minimal in terms of energy costs, but those days are gone.

Do I need a Central Mechanical System or a Unitary (Distributed) Equipment System?

The choice between a Central Mechanical System or a Unitary (distributed) Equipment System depends on building type, how the building will be used, ventilation requirements, zoning, energy metering, and other factors. Central plants usually house all of the mechanical systems for something like a large retail building or office tower. Unitary systems are often used in multi-residential buildings, schools, and hotels. With this type of distributed system, each room has its own heat pump or heating/air conditioning unit. Taliotis Engineering can help you decide on the system that would be most efficient and cost effective for your situation.

What is geothermal?

Geothermal is a combination of solar energy from the sun and heat from the core of the earth. Solar energy is absorbed at the earth’s surface, while about two to three percent of the stored thermal energy comes from the earth’s hot core. As a result, the ground temperature below nine metres (30 feet) is fairly constant. Its value can be estimated fairly well by the average air temperature over the course of a year.

Geothermal heat pump systems take advantage of the earth’s mass in transferring thermal energy to and from the earth. Heat pumps extract energy and reject energy from the earth through a ground heat exchanger. Thus, in the winter, the ground heat exchanger extracts energy from the earth to heat a building. During the summer, to cool the building, heat is removed and rejected into the ground heat exchanger.

Geothermal systems are also known as GeoExchange systems, ground-source heat pumps, ground-coupled heat pumps, earth energy systems, groundwater heat pumps, surface water heat pumps and others.

Learn more about how geothermal systems work (illustrated) on the Ontario Geothermal Association website.

Why geothermal?

Geothermal systems typically reduce energy costs by 25% to 60%. As fossil fuel prices rise and the need to cut carbon emissions intensifies, geothermal systems make more and more sense.

Geothermal systems can completely eliminate the need for fossil fuels for winter heating, or at least significantly reduce it. Natural gas, propane, or other fossils fuels (or electricity) may only be needed to boost domestic hot water temperature.

Other benefits of a geothermal system:

For more information on geothermal systems, visit the GEO website at www.geoexchange.org

When does it make sense to use geothermal?

After assessing your building site, Taliotis Engineering can help you decide if a geothermal system makes sense for your commercial, institutional, or industrial building. Geothermal can be considered for most buildings that require a combination of heating and cooling. The suitability of your location will depend on the land area available, the geology of the site, and the proximity to a lake or pond (where appropriate).

In general, a building that requires almost all heating or almost all cooling is not a good candidate for geothermal. In this case, a dedicated heating or cooling system makes more sense economically. There are exceptions. For example, if a building requires constant cooling and is located beside a lake, geothermal cooling is a viable option. Sometimes an integrated system using geothermal as the base, with a boiler or cooling tower for peak demands, is a cost-effective solution (also known as a hybrid geothermal system). In other situations, a hybrid system that incorporates geothermal with other renewable technologies, such as solar thermal, can be considered.

Taliotis Engineering can conduct a feasibility analysis to develop a holistic view of your projected building loads and energy usage. With this information, we can help you assess your alternatives. If geothermal is not the right option, we will work with you to find the most energy and cost-efficient solution for your situation.

Are there any government grants for geothermal systems, renewable energy, and energy efficiency?

The Government of Canada encourages businesses to invest in geothermal energy systems through beneficial tax measures. The CCA Class 43.2 includes geothermal heat pump equipment and district energy equipment that distributes thermal energy from geothermal heat pumps. According to the June 6th, 2011 budget, Class 43.2 “allows the cost of the assets to be deducted for tax purposes at a rate of 50% per year on a declining balance basis” – which is faster than would be implied by the useful life of the assets.

Currently, the Canadian Government offers the ecoENERGY Retrofit - Homes program. The grant is up to $5,000 for replacing your heating system with a more efficient system. This grant program runs from June 6, 2011 to March 31, 2012. See http://oee.nrcan.gc.ca/residential/personal/retrofit-homes/retrofit-qualify-grant.cfm?attr=4 for details.

For Ontario residents, the Save ON Energy program offers an incentive of $250 toward the purchase and installation of an Energy Star qualified central air-conditioning system. This incentive is for installations completed between Jan. 1, 2011 and Dec. 31, 2011.

There are also a variety of U.S. federal and state grants for renewable energy and geothermal systems. Visit the Database of State Incentives for Renewables and Efficiency (DSIRE).

What is a Geothermal District Energy System?

A district energy system transports steam, hot water, chilled water, or geothermal fluid from a central plant to many buildings through pipelines. District cooling has a dedicated central plant for making chilled water. District heating has a central plant for making hot water or steam, but can use a co-generation plant to create electricity in the process. A district energy system will transport fluid that geothermal heat pumps can use in each particular building.

Roger Taliotis has experience designing community based district energy systems using geothermal. In essence, the concept of an integrated system with geothermal normally done on one building is done on a macro scale, with thermal energy being transported from building to building. Thermal energy can be extracted and rejected through a common ground heat exchanger when necessary. Geothermal district energy systems are ideal when synergies between different building types are available, such as ice hockey rinks and shopping malls near a residential subdivision.

These systems, like the one Roger Taliotis helped design for the town of Gibsons, BC, provide an excellent solution to energy conservation, cost reduction, and emissions challenges for city and regional planners.

How does a Thermal Energy Storage (TES) system work?

A TES system freezes water in an insulated tank during periods of low cooling demand in a building (e.g. at night). Later, instead of cooling on demand, the stored cooling is used to air condition a space or to meet process cooling loads by gradually melting the ice. Using reserve cooling capacity lowers electrical capacity requirements and energy costs. It also takes advantage of load shifting or demand shifting, which is ideal where time-of-use billing is in place.

For handling cooling loads, the size of the heat rejection apparatus (cooling tower, fluid cooler, condenser, geothermal ground heat exchanger, etc.), must be able to handle the peak cooling requirement. With TES, the cooling load is distributed throughout the day, which means the size of the heat rejection equipment can be reduced.

In buildings with high peak cooling loads utilizing geothermal technology, a TES system can significantly reduce the size of the ground heat exchanger required compared to buildings with only a geothermal system. With TES, the energy rejection is spread throughout the day, thus the ground heat exchanger does not have to dissipate a large quantity of heat during periods of high demand.

Taliotis Engineering can examine your building project to see if thermal energy storage makes sense.

What is a Solar Assisted Geothermal Heat Pump (SAGHP) system?

SAGHP systems are also known as geo-solar systems. This type of system can be considered for buildings that are heating dominant for energy. The solar thermal modules provide additional thermal energy that can supplement the geothermal system. One possible setup is having solar thermal modules provide domestic hot water heating, with any excess thermal energy put into the geothermal system.

Other FAQ’s for geothermal

Other common questions specifically about geothermal heat pump systems for residential and small commercial applications can be found here: