Solar Ventilation Fans: Benefits, How to Install & Practical Advice

Team SB
Updated: Jun 4, 2024

Although their specific functions and applications differ, ventilation fans are sometimes used interchangeably with the term exhaust fans, and are devices widely used in residential, commercial and industrial settings.

Solar ventilation fans are one of the latest outcomes of solar energy's penetration into humans' daily production and life, offering several marked benefits over traditional counterparts.

Table of Contents

What Are Solar Ventilation Fans?

Akin to traditional fans, solar ventilation fans are designed to improve the ventilation of indoor spaces, but they harness solar power instead of consuming electricity from connected circuits.

In detail, a solar-powered ventilation fan typically consists of a solar panel, fan motor, fan blades and housing. Some advanced products will incorporate a thermostat, remote control or battery storage module.

According to the design, the solar panel of solar ventilation fans can be either:

Stationary
Adjustable

A stationary panel is fixed on top of the fan, generally flush-mounted inside the top case and level with the surroundings. In contrast, an adjustable design means that the solar panel is installed on a horizontally rotatable and vertically tiltable base.

Regardless of the design, the solar panel captures sunlight and converts it into clean, direct current (DC) electricity to power the fan motor that is connected to fan blades.

The fan blades will spin and create airflow, which pulls air out of the indoor spaces and allows fresh outside air to enter through openings of the structure or intake vents. This process helps lower the inside temperature, or improve air circulation via expelling stale or polluted air to the outside.

Ventilation fans with a thermostat can be set to activate only when the indoor temperature exceeds a certain threshold. When combined with a battery storage module, the fan can operate 24 hours per day without consuming power from the grid.

How to Install a Solar Ventilation Fan?

Solar ventilation fans are generally installed on rooftops. Before installation, prepare all the materials and tools needed beyond the fan, including jigsaw or reciprocating saw, drill with appropriate bits, screwdriver, roofing sealant, ladder, measuring tape, pencil or marker and safety gear.

Step #1: Choose the Right Location

Make sure the spot chosen allows for even airflow when in operation, and ensure maximum sunlight exposure throughout the day for the panel.

Step #2: Measure and Mark

Examine the indoor space and decide on the spot for the fan. Make sure there are no obstacles. Then get to the roof and evaluate the solar irradiation. By weighing up the ideal spot for ventilation and for sunlight absorption, confirm and mark the exact spot for installation.

Step #3: Cut the Opening

Use a measuring tape to mark the dimensions of the fan unit. Drill a starter hole on the marked spot and then use a saw to cut out the marked section.

Step #4: Install the Fan

Place the solar ventilation fan into the opening just cut, and secure the fan with screws provided associated with the product. Make sure to apply sufficient roofing sealant around the edges of the housing to ensure it is watertight.

Products like solar ventilation fans with an adjustable panel have their panel module separated. Hence, you should first complete the installation of the panel on top of the fan as well as the wiring between the panel and the fan.

It is also recommended to give a quick test to check if the connection is fine and the fan can operate with the solar power generated before applying the sealant.

Step #5: Test the Fan

After the sealant is fully dry and set, turn on the switch of the fan during daytime or when there is sufficient sunlight. Test if the fan starts operating.

Step #6: Final Sealing and Inspection

Check all the connections and ensure there are no loose parts. Then switch off the fan and apply additional roofing sealant around any penetrations or attachments to make sure everything is well watertight.

Finally, when all sealant is set, turn on the fan and let it run with solar power.

What Are the Benefits of Solar Ventilation Fans?

By leveraging the free, inexhaustible sunlight, solar ventilation fans offer many benefits for both residential and C&I applications, including garages, warehouses, factories, and agricultural facilities, to name a few.

Hassle-Free Installation: By re-visiting the installation process, you can find that no wiring, coupled with circuit conduit installation, is needed when installing these fans. This contributes to big savings for both materials and labor, as well as minimal retrofit or damage to the structure.
Extended Roof Longevity: By eliminating the need for wiring and conduit installation, fewer drilling holes are required, thereby reducing the risk of roof leaks and preserving the integrity of the roofing materials.
Reduced Energy Costs: Solar ventilation fans, especially those coupled with energy storage modules, can realize autonomous operation 24h/day without consuming other electricity.
Low Maintenance: Most solar panels today come with a lifetime of 25-30 years, meaning that in most cases a replacement is not needed. No wiring also implies that there is no need to replace any degraded or bit electric wires within the fan’s lifetime.
Decarbonization: These fans take advantage of solar energy for ventilation. It is an important means of decarbonization for households and commercial and industrial facilities. Their reliable performance helps to reduce the load on air conditioning systems, if any, leading to further energy savings and lower operating costs.

Things to Consider When Choosing and Using These Fans

When selecting these products, as with traditional ventilation fans, it's essential to determine the appropriate airflow to adequately ventilate the space.

Airflow is measured by the cubic feet per minute (CFM). For example, 1,000 CFM means the fan is capable of moving 1,000 cubic feet of air per minute.

CFM is calculated using this formula below: CFM = Space Volume ÷ Minutes/Change

For a medium-sized attic, let's say its volume is roughly 10,000 cubic feet and it demands an air change rate of 3 times per hour. Then, under an ideal static pressure, the suggested CFM of the solar attic fan may be: 10,000 cubic feet ÷ 20 minutes = 500 CFM.

For larger spaces such as commercial studios, or those with more frequent air change per hour, a large CFM is required. However, the power rate, measured in watts, will increase as the CFM grows. But the maximum power output of either stationary or adjustable design would not exceed 100 watts. Therefore, to maintain a reliable operation, a solar ventilation fan with high capacity would require a larger, separated panel or dual power source design.

In addition, the noise issue should also be considered. Under equal conditions, large CFM generally results in a higher decibel (dB). If the project underscores quiet operation, it would be better to opt for a ventilation fan with brushless DC motor which would produce lower noise.

Though solar ventilation fans are of low maintenance, it is necessary to inspect the cleanliness of the panel regularly since it would impact the performance of energy conversion and, subsequently, the fan.

The Prospect of the Solar Ventilation Fan Market

The market for solar ventilation fans presents a promising growth opportunity. Study reveals that the market will reach a value of $1.44 billion in 2024, and is expected to reach $2.25 billion by 2034.

Firstly, the growth is driven by the surge in demand for energy-efficient ventilation systems. Solar-powered ventilation fans utilize renewable solar energy and offer an eco-friendly solution for house and business owners. Their utilization in commercial and industrial segments aligns with the goal to achieve ‘100% renewable energy’ for many entities.

In the meanwhile, many governments worldwide are promoting renewable energy adoption through incentives and subsidies, directly encouraging the installation of solar ventilation systems.

Additionally, technological advancements in solar panel efficiency, battery storage and smart home integrations have further enhanced the performance and reliability of solar ventilation fans. Coupled with their inherent features of hassle-free installation and low maintenance, solar ventilation fans are an attractive option for property owners, and solar business investors.