September 03, 2010
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Air Heating / Ventilation

Technology Name:

Solar Air Heating

Date Introduced in the market:

1990s

Maturity of the technology:

Commercially available. Growing industry with commercial applications installed in Canada and around the world.

Type of energy that can be produced (i.e. thermal, electrical):

Thermal

Typical applications:

To heat air for space heating of homes, barns, workshops, commercial and industrial facilities.
To reduce the use and dependency on gas and electricity for air heating systems.
To provide heated fresh air intake for building and heat processes.
To assist with destratification of air
As combined air heating and wall cladding

Expected Pay-Back:

Analysis of solar air heating systems have demonstrated IRRs of 10-30% is possible with a simple pay back of 2- 5 years.

Range of possible dimensions and sizing considerations for the system:

Solar air heating systems range from very small, a few square metres, to thousands of square meters.

Range of performance of the technology per unit installed:

Solar air heating systems collect 1-3GJ/year per m2 of collector.

Range of costs per unit of energy and per system (installed, and maintenance costs):
Installation costs:

Collector $100 to $250/m2
Ventilation system $0 to $100/m2
Where solar air collectors are installed on new building or when wall cladding is in need of replacement, the cost of conventional cladding is offset.

Design, Installation, Maintenance & Operation of Solar Air Heating System:
Design of a Solar Air Heating System:

Expertise/knowledge required can include: metal siding contracting, solar air heating system design, HVACR contracting, electrical, mechanical, general construction.

Installation of a Solar Air Heating System:

Expertise/knowledge required can include: metal siding contracting, solar air heating system design, HVACR contracting, electrical, mechanical, general construction.

Maintenance of a Solar Air Heating System:

Solar Air heating systems are low to maintenance free. Does this comment encompass the maintenance that the fan/ventilation system might require or should we add a sentence on the maintenance requirement for the fan/ventilation system?

Operation of a Solar Air Heating System:

Solar air heating systems require minimal ongoing operation. Solar air collectors have no moving parts and the ventilation systems can be designed to automatically bypass the hot air on warm days. The fan/ventilation system has moving parts, maintenance must be required. Could you add a sentence on the level of maintenance to expect for the fan/ventilation system. Ex: Ventilation systems require typical operation and maintenance.

Training for designers and installers:

Solar air heating systems are fairly simple systems that installers with good construction and HVACR skills can install. A wide variety of opportunities exist for general solar training, from online courses and free information to hands on workshops and college courses. See www.cansia.ca for more information. For information about training in ventilation systems, see www.hrai.ca, the heating, refrigeration and air conditioning industry association of Canada.

Range of Operational & Maintenance requirements (ex: how much labour time per week for how many people):

Requires virtually no maintenance or operating time. Ventilation systems require typical operation and maintenance. Ventilation systems may be automated.

Potential problems or challenges:

Solar Air heating systems, while commercially available in Canada are not often considered at the time of construction planning when implementation is most cost effective.

Other considerations:

Investigate Maintenance contracts or warrantees.
Ensure system is designed for climate and air heating and ventilation needs.
Ensure southern exposure clear of obstructions between the hours of 10 AM and 3 PM or longer.

Permitting:

Generally, no special permit is required for solar air heating installations. The same permits for wall cladding will likely apply. Do check with your local permitting department before beginning any project.

Range of warranties and life expectancy of the systems:

Warranties: 1-20 years
Life Expectancy: over 20 years

Solar Resources Assessment:

Site specific solar resources can be measured by visual techniques and inspection or through commercially available solar site analysis tools. The U.S. National Renewable Energy Laboratory has extensive solar radiation resource information at http://rredc.nrel.gov/solar/. Links to Canadian solar radiation data can be found at http://www.canren.gc.ca/resou_asse/index.asp?CaId=55&PgId=452

Canadian Solar Resource maps are available at: http://atlas.nrcan.gc.ca/ and https://glfc.cfsnet.nfis.org/

Inputs and outputs for the technology:
Outputs:

Solar air heating systems directly heat ambient air and use convection or fans to direct the hot air through a ventilation duct system.

Inputs:
Sun:

A southern or south western wall relatively unobstructed from the hours of 10 AM to 3 PM is preferred.

Electricity:

The ventilation system that the solar air collectors feed into may use fans and thermostatically or electrically powered bypass baffles. The amount of electricity used is based on the type of ventilation system and the amount of air flow required.

Potential combination with other energy systems (hybrids and combination systems):

Photovoltaic (solar electric): solar electricity can be used to power any electric loads, such as fans, to allow off grid operation of the air heating system. A relatively new product combines the technology of perforated-plate solar collectors with PV panels to improve the efficiency of PV systems and utilize the waste heat generated by roof mounted PV panels. Need an hyperlink or an illustration or more information on this new product - people will want to know what is this new product.

Links to other sources of information:
  • Monitoring system pressure.
  • Replacement of anti-freeze solution after approx 7-10 years (for closed loop pressurized systems).
  • Repair or replacement of circulation pumps.

Operation of Solar Hot Water Space Heating System:
Can be monitored and operated by homeowner with instruction from contractor/installer. Operator of a commercial hot water system should be knowledgeable of the system's flow rates, pressure drop and other technical specifications.

Training for designers and installers:
CanSIA is working with colleges to implement training programs for designers and installers of SHW systems, based on the North American Board of Certified Energy Professionals SHW certification. A wide variety of training opportunities exist from online courses and free information to hands on workshops and college courses. See www.cansia.ca for more information. For heating training see www.hrai.org, the Heating, Refrigeration and Air Conditioning Institute of Canada.

Range of Operational & Maintenance requirements (ex: how much labour time per week for how many people):
A solar heating system requires only periodic monitoring and maintenance to ensure proper functioning.
Pumps and valves of radiant heating system require routine maintenance.
Monitoring and Operation: ?.? hr/month - ? hr/year, ? person
Maintenance: ?-? hr/year, ?-? person

Potential problems or challenges:
To ensure system performance:
Investigate certification of collectors or evacuative tubes. Two rating and certification systems are: The Solar Rating and Certification committee (SRCC) and Florida solar Energy center collector approval (FSEC)
A new program is in place to provide Canadian Standards Association certification (CSA F379-5) for solar hot water systems and systems in Canada are now able to apply for CSA certification.
Other considerations:
Investigate Maintenance contracts or warrantees.
Ensure system is designed for climate and heating loads.
Ensure southern exposure clear of obstructions between the hours of 10 AM and 3 PM or longer.

Permitting:
Permitting is inconsistent across Canada. Local permitting offices and decision makers may not be familiar with solar hot water applications and their requirements and may need to be informed. Be sure to investigate potential permitting requirements before beginning any project.

Range of warranties and life expectancy of the systems:
Warranties: 10 years
Life Expectancy: 20 - 30 years
Solar Resources Assessment:
Site specific solar resources can be measured by visual techniques and inspection or through commercially available solar site analysis tools. The U.S. National Renewable Energy Laboratory has extensive solar radiation resource information at http://rredc.nrel.gov/solar/. Links to Canadian solar radiation data can be found at http://www.canren.gc.ca/resou_asse/index.asp?CaId=55&PgId=452

Canadian Solar Resource maps are available at: http://atlas.nrcan.gc.ca/ and https://glfc.cfsnet.nfis.org

Inputs and outputs for the technology:
Outputs:
Solar Thermal collectors directly convert energy from the sun to useable heat energy. Heat produced by the SDHW is used for space heating in a radiant system, usually in addition to hot water use (See SDHW)

Inputs:
Sun:
A southern exposure unobstructed from the hours of 10 AM to 3 PM is preferred.

Anti-freeze solution and heat exchanger:
Many systems use an Anti-Freeze liquid (usually propylene glycol) and a heat exchanger to convert energy from the sun to useable heat energy. The anti-freeze solution usually lasts many years before having to be replaced.

Electricity:
Most systems have electric pumps that circulate propylene glycol through a pressurized closed loop. The amount of electricity required is minimal. It could be provided by the grid or by other sources such as a PV panel (see under "Potential combination …" for more detail).
The radiant heating floor or baseboard will have circulation pumps to control the flow of heat exchange liquid through the pipes.

Potential combination with other energy systems (hybrids and combination systems):
Water Heating and Space Heating:
Solar radiant space heating systems are usually most efficient when designed to meet both a space heating and a year round hot water load.

Photovoltaic (solar electric):
Most systems have electric pumps that circulate propylene glycol through a pressurized closed loop. The amount of electricity required is minimal. These electric pumps can be DC and run by a PV panel ensuring hot water production when there is no electrical grid.

Roofing Material and PV:
Some Solar Hot Water collectors are specifically designed to double as roofing material. If you need a new roof, this is a good time to consider solar hot water roofing collectors (or any solar roof mounted system). Some roofing solar hot water collectors integrate with Photovoltaic (solar electric) roofing materials and can be installed together to perform the function of shingles or other roofing materials. Offsetting the cost of roofing materials helps improve the cost effectiveness of the solar system.

Links to other sources of information:


Sources of supply (in Canada):

Check CanSIA's website for contact information for suppliers and installers in your area. www.cansia.ca

Énergie Solaire Québec sells for a small fee (free with membership) a list of renewable energy suppliers and businesses in Quebec. http://www.esq.qc.ca/

Recommendations on how to proceed with a project development:
Contact CanSIA: check their database for a local installer.
Finding a contractor: As when hiring any contractor, ask for references from other clients or examples of their work and past experience.
Contact your local building inspector and municipal permitting office.
Ensure you have the necessary permits and the inspector is familiar with your plans before construction.
Check the links above for more information.
Investigate possible government incentives or tax rebates. Contact CanSIA or NRCan for more information.

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Created: 02-13-2008
Modified: 03-31-2008