The human species’ ability to manipulate the world around us has long been one of the main factors that separates us from other life on this planet.
And as our technological prowess grows, it’s begun encompassing the near limitless potential of solar energy through photovoltaic systems as well as passive heating elements that have been used for centuries.
Today, businesses and residential homes alike have also adopted this renewable energy source to power solar heating cooling systems to help regulate the indoor temperatures of their facilities. Some of these systems are known as “solar space heating and cooling” systems.
This impressive new kind of heating/cooling provides homeowners and business owners the ability to cut down on utility bills while taking advantage of a fully renewable resource. But these systems aren’t one-size-fits-all.
Let’s take a bit more in-depth look at each of these systems below as well as the various pros and cons of each.
Transpired Air Collectors
One of the most common types of solar space heating system involves the use of transpired air collectors.
Transpired air collectors consist of a large wall of perforated sheet metal attached to a southern-facing wall with a gap of space maintained between the two vertical surfaces. As the sheet metal heats up due to exposure to the sun, a ventilation fan sucks the warmed air through the holes, into the gap, and through the ventilation system where the warmed air is then distributed throughout the facility.
These simple systems can actually heat the surrounding air by as much as 40 degrees Fahrenheit.
A transpired air collector is virtually maintenance free, doesn’t require any expensive glazing like other solar heating systems, and even helps prevent heat loss at night by collecting ambient heat from the building as well.
The United States’ main renewable energy laboratory, the National Renewable Energy Laboratory (NREL), claims that these systems will actually pay for themselves in reduced heating costs in just 3 to 12 years.
However, this particular method of heating is not normally suitable for residential homes for a number of reasons. In the first place, they’re generally only effective when covering large south-facing walls. Many homeowners may find the systems to be a bit of an eyesore as such.
What’s more, they also tend to be most effective in facilities with a high ventilation load, making the tightly closed off systems you’ll find in most residential homes unfitting for this type of heating system.
Solar Liquid-Based Heating
Rather than heating the air directly as with transpired air collectors, solar space heating systems can also come in the form of liquid-based heating. These systems focus on using solar energy to increase the temperature of a liquid base and then transferring that heated liquid to a distributor where the heat is transferred throughout the facility.
The energy collectors for these systems can be flat-plate collectors, evacuated tube collectors, or parabolic-trough collectors, just to name a few.
- Flat-Plate Collectors – Solar collectors with water pipes running directly through them. The solar energy captured heats up the plates which then increase the temperature of the pipes and the liquid contained within.
- Evacuated-Tube Collectors – Glass reflectors help intensify the heat absorbed by these tubes. Tubes are separated by a layer of vacuumed space to help control heat loss. Can be heated over 250 degrees Fahrenheit, substantially more than flat-plate collectors.
- Parabolic-Trough Collectors – A parabolic trough helps collect and concentrate reflected light onto a single pipe in order to heat the liquid inside. These systems tend to be more complex and thus, as the EPA notes, more expensive.
Solar Space Cooling Systems
It might sound counterintuitive to think that solar energy can be used to actually decrease the ambient temperature of a facility but researchers have found a way to harness this renewable energy to serve such a purpose. In fact, many cooling systems have been using this technology since the mid to late 20th century.
It helps to think of the energy provided by solar collection not so much as “heat” as with the systems discussed earlier but rather as a source of electricity used to power such cooling systems. This energy source can be provided by photovoltaic systems which convert solar power directly to electricity or through thermal systems where heat energy is chemically converted into power.
Either way, solar space cooling systems are powered directly by the heating power of the sun.
Solar Heating & Cooling: An Exciting New Frontier
Transpired air collectors, liquid-based heating systems, and solar space cooling systems provide modern consumers with a number of options when it comes to renewable interior temperature control and each have their own pros and cons.
Solar heating and cooling systems like these are playing an incredibly significant role in providing renewable and inexpensive energy to businesses and residential homes alike, making solar power an even more viable energy source.