Active solar heating refers to collecting heat from the sun and storing and using it primarily for domestic hot water heating or space heating.
It is called active because the captured heat transfers to a place where it can be stored or used with mechanical and electrical equipment, such as pumps and fans.
Difference Between Active and Passive Solar Heating
Active Solar Heating
Electrical and mechanical equipment are used in active solar heating, such as solar panels and air collectors.
It is a refined form of solar energy and does not require a specific orientation to your house. It uses solar collectors to collect sunlight and convert it into heat for future uses.
Passive Solar Heating
Using direct sunlight to generate heat or electricity makes it passive solar heating.
It does not require the use of mechanical or other energy systems, which is why it becomes a more natural form of solar energy.
However, your house must have the proper orientation if you want to use passive solar heating compared to active solar heating.
How Do Active Solar Heating Systems Work?
Active solar heating systems use several devices to collect and store heat from the sun. One good example is solar thermal energy using solar collectors, which capture solar radiation and transform it into thermal energy.
Flat-Plate Collectors
A flat-plate collector is a type of solar thermal collector used to collect and store heat from the sun.
It is usually made up of a dark-colored absorber plate placed in an insulated box. The absorber plate absorbs sunlight, which then heats the fluid running through it.
Radiant Panels
Radiant panels are another type of solar thermal collector.
They work by absorbing sunlight and converting it into heat, which then transfers to the environment through radiation.
It is often used in radiant heating systems where the heat warms the floors or walls of a room. Radiant panels have three types: floor, wall, and ceiling.
Active Solar Heating Economics and Other Benefits
The economics of active solar heating systems are attractive.
In many cases, the payback period is less than five years, and the systems have a lifespan of 20 years or more. But solar heating system costs may vary.
Your fuel bills may reduce in the winter upon heating your home with an active solar energy system.
Additionally, the amount of air pollution and greenhouse gases that result from your use of fossil fuels for heating or generating electricity will reduce.
Selecting and Sizing a Solar Heating System
Selecting an effective solar energy system requires consideration of various factors.
These are the design, site, and heating needs of your house. The options may be restricted by local covenants. For instance, installing solar collectors on certain parts of your home may be declined by homeowners associations.
How much heat a solar system can provide is determined by the local climate, collector area, and the collectors’ efficiency.
Designing an active system to provide between 40% and 80% of the home's heating needs is typically economical.
Aside from using solar air heater collectors that require no heat storage and heat one or two rooms, systems providing less than 40% of a home's heat are hardly cost-effective.
On top of that, an insulated and well-designed home that includes passive solar heating techniques may barely need supplemental heat other than solar and require a smaller and less costly heating system.
Most mortgage lenders and building codes require a backup heating system because designing an active system to supply enough heat is often not practical or cost-effective.
When the solar system cannot meet the heating requirements, extra or backup systems supply heat.
Controls for Solar Heating Systems
Usually, controls for solar heating systems are more complicated since more signals require analysis, and there are more devices to control.
Solar controls use switches, sensors, and motors for the system to operate. The system uses other controls to avoid extraordinarily high and freezing temperatures.
The performance, operation, and cost of these controls vary. Other control systems monitor the temperature in different parts of the system to help determine its operation levels.
The most sophisticated systems use microprocessors to optimize and control heat transfer and delivery to storage and different zones of the house.
A differential thermostat is the heart of the control system, which measures the difference in temperature between the storage unit and collectors.
When collectors become warmer than the storage unit, from 10° to 20°F, the thermostat turns on a fan or pump to circulate air or water through the collector to heat the house or the storage medium.
Separate controls may not be necessary when used with a room air collector to ensure that the system will operate in case of a utility power outage.
Installing and Maintaining Your Solar Heating System
Current controls and collectors are high quality, but it can prove challenging to look for a competent contractor who can properly install and design the system.
The performance levels of an active energy system depend on system design, installation, and effective location, along with the components' quality and durability.
It must be appropriately maintained to optimize the performance and avoid breakdown after a system is put in place.
Keep in mind that different systems require different kinds of maintenance. Most solar water heaters are covered automatically under your homeowner's insurance policy. But the damage from freezing does not.
Final Thoughts
Active solar heating systems are a great way to supplement your home's heating needs, especially if you live in a sunny climate.
They are also more environmentally friendly than traditional heating systems and can save you money on your energy bill.
If you are thinking about installing a solar heating system in your home, do your research and hire a qualified contractor.
With proper installation and maintenance, your solar heating system will provide you with years of trouble-free operation.
FAQs
1. What is active solar heating?
Active solar heating refers to a system where solar panels collect heat and circulate it through the home.
2. What is the difference between active and passive solar heating?
The main difference between active and passive solar heating is that passive solar heating relies on direct sunlight and active solar heating uses solar collectors to collect sunlight and convert it into heat for future usage.
3. How do active solar heating systems work?
Active solar heating systems use flat-plate collectors or radiant panels to collect heat from the sun.
4. What are the economics and other benefits of active solar heating?
The main economic benefit of active solar heating is that it can save you money on your energy bill. Other benefits include being more environmentally friendly than traditional heating systems and providing a backup source of heat in case of a power outage.
5. How do I select and size a solar heating system?
When selecting and sizing a solar heating system, you will need to consider the design, site, and heating needs of your house.
