Size flat-plate and evacuated tube solar thermal collectors for space heating and domestic hot water. Calculate collector area, tilt angle, and annual solar fraction by location.
Size domestic solar hot water systems for residential and commercial applications. Calculate collector area, storage tank volume, backup energy required, and payback period.
Calculate solar heat gain through windows by orientation, SHGC, and shading factor. Monthly profiles, peak cooling load impact, and equipment sizing recommendations.
Size south-facing glazing and thermal mass for passive solar heating. Calculate solar savings fraction, auxiliary heat required, and overheating risk for any Canadian climate.
Calculate how many solar PV panels offset your HVAC electricity load. Size a PV system from annual heating and cooling energy use. Includes net metering payback analysis.
Calculate peak and monthly average solar irradiance by latitude, tilt, and azimuth. Uses ASHRAE clear-sky model with diffuse and direct components for any Canadian or US location.
Calculate overhang depth to block summer sun while allowing winter solar gain through south-facing windows. Outputs shading fraction by month for any latitude.
Calculate the solar fraction (percentage of heating load met by solar) for domestic hot water and space heating systems. Uses the f-chart method for flat-plate and evacuated tube collectors.
Analyze solar-driven absorption cooling systems. Calculate COP, collector area required, and compare solar cooling economics vs. conventional electric AC for your climate.
Calculate payback period and ROI for solar thermal, solar water heating, and PV systems. Accounts for Canadian Greener Homes incentives, utility rates, and annual degradation.
Calculate solar heat gain through glazing by orientation, SHGC, and external shading. Outputs peak cooling load contribution and monthly solar gain profiles for any Canadian climate zone.
Model net metering credits for grid-tied PV systems across Canadian provinces. Calculates monthly export credits, annual bill offset, and payback period under provincial net metering tariffs.
Size hybrid photovoltaic-thermal (PVT) collectors that produce both electricity and heat simultaneously. Compare combined efficiency vs. separate PV and thermal panels for Canadian installations.
Analyze solar-assisted heat pump systems where solar thermal collectors boost the heat pump source temperature. Calculate COP improvement, collector area, and annual energy savings for cold Canadian winters.
Calculate shading from adjacent buildings, trees, and roof overhangs on solar collectors and windows. Outputs hourly shading fractions by month to refine collector placement and glazing design.
Find the optimal azimuth and tilt angle for solar collectors or glazing at any Canadian latitude. Compare annual energy yield across orientations and quantify the penalty for off-south installations.
Size thermal storage tanks for solar heating systems. Calculate storage volume, heat loss, stratification, and charge/discharge cycles to match supply and demand across day and night periods.
All-in-one sizing tool for complete solar HVAC systems. Input load profile, location, and system type to get collector or panel count, storage size, backup capacity, and estimated annual output.
Solar and HVAC: how they connect
Solar interacts with HVAC in three distinct ways. Solar thermal systems collect heat directly for space heating or domestic hot water. Photovoltaic panels generate electricity that offsets what HVAC systems consume. And passive solar design uses building orientation, glazing, and thermal mass to reduce heating loads without any mechanical system at all.
Solar thermal vs. PV for HVAC
Solar thermal collectors convert 50 to 70% of incident solar energy to useful heat. PV panels convert 18 to 22% to electricity. For heating applications, thermal wins on efficiency. For cooling and year-round flexibility, PV wins because electricity can power anything. In Canada, solar thermal makes the most sense for domestic hot water, where it can meet 50 to 70% of annual demand with a 5 to 8 year payback using the solar water heater calculator and solar fraction calculator.
Passive solar in Canadian climates
Passive solar works well in southern Canada where heating season coincides with clear winter skies. Vancouver is cloudy in winter and less effective. Toronto, Calgary, and Montreal have 60 to 70% winter sunshine and good passive solar potential. The key constraint is overheating in shoulder seasons, so a thermal mass and an operable shading strategy are essential. The overhang sizing calculator handles this geometry precisely, and the solar orientation calculator confirms the best tilt and azimuth before finalizing a design.
Solar gains in cooling load calculations
West-facing windows can contribute 40 to 50% of a room's peak cooling load on a summer afternoon. Quantify this with the solar heat gain calculator, then feed the results into the cooling load calculator for complete system sizing. The solar shading calculator also helps quantify how nearby obstructions reduce that gain.
Related tools you may need
- After sizing a solar thermal system, size the matching thermal storage tank or run the solar system sizer for a complete all-in-one design.
- For grid-tied PV, model provincial credits with the net metering calculator and check overall economics with the solar HVAC payback calculator.
- Check local irradiance and design conditions first with the solar irradiance calculator.
- For cold-climate heat pump performance, review the solar-assisted heat pump calculator and the PVT collector calculator for combined heat and power options.
- Check ventilation compliance with the ASHRAE 62.1 ventilation calculator.
Frequently Asked Questions
Solar thermal collectors convert 50 to 70% of incident solar energy directly into useful heat, while photovoltaic panels convert 18 to 22% of incident energy into electricity. For heating applications, solar thermal wins on efficiency since it skips the electrical conversion step entirely. For cooling and year-round flexibility, PV wins because electricity can power any equipment, not just heating, including heat pumps, fans, and controls. Use the solar thermal calculator and PV to HVAC load calculator to compare both approaches for your specific building.
Passive solar works well in southern Canada where the heating season coincides with clear winter skies. Toronto, Calgary, and Montreal have 60 to 70% winter sunshine and good passive solar potential, while Vancouver's cloudier winters make it less effective. The key design constraint is managing shoulder-season overheating with thermal mass and shading. Use the passive solar design calculator alongside the overhang sizing calculator to design both the glazing and the shading together.
A well-sized solar water heating system can meet 50 to 70% of annual domestic hot water demand in most Canadian climates, with typical payback periods of 5 to 8 years after available incentives. The exact fraction depends on collector area, orientation, storage volume, and household hot water use. Use the solar fraction calculator and solar water heater calculator for a location-specific estimate, then check the solar HVAC payback calculator for the full financial picture including Canada Greener Homes incentives.
Yes, all AskHVAC.ca tools are fully responsive and work on any smartphone or tablet without an app install. They run entirely in your browser, and results can be exported to PDF or CSV directly from your phone. The interface switches between Imperial and Metric with a single tap. Use them freely at the job site, in the truck, or in the office.