For the last 10 years, I have successfully used a solar powered heater and the free sun''s energy for space heating.
I''ll explain how in a minute.
First, let''s see how and where you can use solar space heaters, so-called "solar thermal air heaters".
By simply heating the air, you can accomplish the following:
For example, you can use solar powered space heater to heat air blown directly into the house''s living spaces. This is called direct solar air heating.
The solar air heater will send heat into the house whenever the solar-heated air is warmer than the house.
You can also use solar air heaters to heat your house indirectly. For example, suppose you have an unheated basement or crawl space beneath your house. In that case, you can blow solar-heated air directly into the crawlspace or basement. The warm solar-heated air will rise up to the heat the underside of the first floor. This is the simplest form of radiant floor heating and is one of the most comfortable and productive solar heat methods.
Another indirect use of solar heat is to use solar air heaters to provide solar-heated air to the outside unit of a heat pump. Using this approach causes the heat pump to work more efficiently and produce more heat with less electricity.
Suppose you operate bathroom fans, clothes dryers, kitchen exhaust fans, fireplaces, gas, propane, or oil water heaters. In that case, you can use your solar air heaters to preheat outside air that enters the house to feed these fans and fuel-burning appliances.
The solar air heater can blow warm solar-heated air directly into the living spaces to individual rooms or heat larger spaces. The solar air heaters are set up to pull fresh outside air in at one end and discharge warm solar-heated air at the other end.
The solar air heater is designed to deliver air about 40 degrees F warmer than the outside air. For example, on a 45 degree sunny day, the solar air heater will deliver air at 85 degrees. solar air heaters will deliver warm air suitable for Direct space heating during much of the heating season for many climates.
However, there will be days when the outdoor temperatures are colder than 35 degrees, there is a strong cold wind, or the skies are partly cloudy when the solar air heater outlet temperature is below 75 degrees. In these conditions, most people will find that the solar-heated air is not adequate for direct space heating and will rely solely on their conventional heating system. Fortunately, solar heated air from the solar air heaters is still useful for many Indirect Space heating applications, producing significant savings on heating bills.
The indirect space heating applications include:
Direct Space Heating is useful where the solar air heater air temperature is more than 10 degrees F warmer than the indoor room temperature. For example 85 F solar air to a 75F room. In this case, the solar-heated air can be blown directly into the occupied space. Even at this temperature, the air stream moving at high speed directly from the fan will feel cool. (Try blowing your 85F breath across your hand 6" from your face, it will feel cool due to the moving air). However, a room full of 85 F still air will feel warm.
Most solar air heater installations are designed to deliver outside fresh air, on sunny days, at about 35-50 degrees F above outdoor temperatures. So, the solar air heaters can be used for direct space heating whenever the outside air is above about 40 degrees F (above 75-90F delivered solar air temperature). The solar air heater air temperatures will obviously drop off if it is cloudy or early morning or late afternoon.
There are three ways to control the operation of the solar air heater fan to ensure that the fan runs when solar heat is available and stops when solar heat is not available. First, you can manually turn the solar fan OFF and ON to match the solar heat available. You can also control the solar air heater with a thermostat that turns it on whenever the temperature of the solar air heater is above a certain temperature, say 75 F. You can also control the solar fan with a Differential Temperature Controller that will turn the fan ON whenever the solar air heater air temperature is warmer than the indoor temperature or any other temperature you set.
To bring the solar heated air into the house, you have two options:
Heat pumps can provide efficient heating when the outdoor temperature is above 50 degrees F. However, the heat pump doesn''t work very efficiently when the temperatures drop into the 40s and 30s and below. As a result, it becomes one of the most inefficient heating systems, not much better than electric resistance heat in an electric furnace or baseboard heater.
However, suppose solar air heaters are used to preheat the air flowing across the outdoor coil of the heat pump. In that case, you can dramatically improve the performance of the heat pump. The warmer air moving across the coil means that the heat pump can operate without electric resistance heat, saving electricity and money. The most significant benefit of this approach is that you can use the solar heated air from the solar air heaters to heat the heat pump, even when it is colder than comfort temperatures. So you get more hours of use and energy savings from your solar air heaters than if you just used them when they were delivering air at 85 F and above. They will save energy at the heat pump even if they deliver 50 F air on a 10 F degree day.
To preheat outdoor air for a heat pump, you need to send the warm air stream across the outdoor coil of the heat pump. This is done by bringing the outdoor solar duct up to the heat pump and flooding the air around the heat pump with warm solar air. A section of outdoor duct that is perforated to allow solar air to be released is installed on the ground around the base of the heat pump. This section is installed about 8 inches away from the unit''s base to allow unimpeded airflow across all coil areas during summer and winter.
The fan inside the outdoor unit will draw air across the heat pump coil. As it pulls air across the coil it will move both the solar heated air and any additional cold outside air it needs across the coil. The more solar-heated air you can provide, the better the heat pump performance will be.
There is no need to solar heat this entire volume of air. Instead, preheating up to a maximum of about ¼ of this air is a better strategy. The preheated air will blend with the outside air to boost the temperature seen by the heat pump. This elevated temperature will result in higher efficiency.
During the spring and fall when the weather is cool, in the 40s and 50s, the solar heated air will bring the blended air temperature up to about 60 F. Most heat pump manufacturers set a maximum operating temperature for their heat pumps of about 60 degrees F. That is why you must use a thermostat that shuts down the solar airflow when the blended air temperature reaches above 60 F. If you know the manufacturer''s maximum operating value, you can adjust the thermostat to shut down when the blended air temperature reaches about 5 F below the maximum. A few heat pumps, e.g., many pool heating heat pumps, have higher operating temperatures. In those cases, you can set the solar airflow cut-off thermostat to higher temperatures according to the manufacturer''s stated values.
The strategy that delivers the most solar heating benefit is to use the solar-heated air directly for space heating, whenever it is warmer than the indoor air, and to run an exhaust fan that exhausts the excess household air across the heat pump coil. Whenever the solar air temperature is below comfort temperatures for direct space heating, the solar air can be sent across the outdoor coil. This approach is more complicated and requires the coordination of two fans. Still, it will deliver more hours of heat at higher efficiency than just heat pump preheating alone.
People who have radiant floor heat know how comfortable it can be. The reasons are simple:
Without radiant floor heating, the floor temperature drops to low 60s. It can be colder if it is over an uninsulated crawlspace. The chart below shows one example of actual crawlspace temperatures in a modular building in North Carolina during three winter days. During those days, the skies were clear and sunny. A solar air heater system would have produced solar-heated air at about 40 degrees warmer than the outside air and filled the crawlspace with warm air. The chart shows the estimated temperature at the top of the crawlspace, just under the floor. The solar air heater system floods the crawlspace with warm air.
Usually, a radiant floor heating system requires a boiler and miles of continuous plastic tubing buried in concrete poured on top of the floors or tubing wound tightly against the bottom of a plywood subfloor, wrapped in shaped aluminum plates, and stapled against the plywood. Hot water is pumped through the water tubing to heat the subfloor below the finished flooring. The maximum temperature of the finished flooring only needs to be 80 degrees F to influence comfort significantly.
However, there is a much simpler way to achieve the benefits of a radiant floor: air as the radiant heating fluid. solar air heaters have been used to heat crawlspaces below first floor rooms to deliver Air-Radiant Floor heating. No complicated plumbing is required because the warm air does all the work of transferring heat to the floor.
About Solar electric heater
As the photovoltaic (PV) industry continues to evolve, advancements in Solar electric heater have become critical to optimizing the utilization of renewable energy sources. From innovative battery technologies to intelligent energy management systems, these solutions are transforming the way we store and distribute solar-generated electricity.
When you're looking for the latest and most efficient Solar electric heater for your PV project, our website offers a comprehensive selection of cutting-edge products designed to meet your specific requirements. Whether you're a renewable energy developer, utility company, or commercial enterprise looking to reduce your carbon footprint, we have the solutions to help you harness the full potential of solar energy.
By interacting with our online customer service, you'll gain a deep understanding of the various Solar electric heater featured in our extensive catalog, such as high-efficiency storage batteries and intelligent energy management systems, and how they work together to provide a stable and reliable power supply for your PV projects.
Related Contents
