Whether it’s sky-high energy bills or a desire to cut down on your carbon footprint, there are many reasons you could want to make the switch to greener options for your home heating and cooling. We have gathered the 10 coolest green HVAC technologies around to give you an idea of what the future of indoor heating and cooling holds for you. If you want to improve your HVAC unit’s energy efficiency, call Integrity AC and Heating today! Our HVAC gurus are very professional and courteous; they want to help your home be as comfortable as can be.


The Earth is truly amazing. All it takes is one look just beneath the surface, and you’ll find a living organism on a scale you can barely comprehend. Deep in the heart of the planet, you’ll find a great deal of hot water and steam. As you go deeper, the temperature continues to rise. This is called geothermal energy, which literally means the internal heat of the Earth. Surprisingly, you don’t have to go that deep to tap into this limitless source of energy. Just a few feet below the surface, water remains a consistent temperature year round, somewhere around 42 to 80 degrees Fahrenheit, depending on where you live. With a geo-exchange system, you can utilize this energy to heat and cool just about any type of building.

The way a geothermal system works is through using heat pumps to capitalize on the constant temperature of the geothermal wells under the ground. These heat pumps can cool a house in the summer and warm it during the winter. That is thanks to the fluid contained within the heat pumps, which can be either water or a refrigerant. During cold weather, the fluid absorbs the geothermal heat and brings it inside to warm the air. In hot weather, it does the opposite to cool the house. 

-Passive Solar

Here’s one that might surprise you, simply because you can take advantage of this with little change to your current set up. The sun is the most consistent provider of green energy. Essentially, you are utilizing your home’s natural design to take advantage of solar heat that is brought in through your windows to handle most of the heating in your home. When the sun raises the temperature in your home naturally, your heating system will have to work less to maintain the heat, which means you’re using less energy. You can supplement passive solar energy with a forced-air system or radiant flooring to keep temperatures cool in the summer and warm in the winter.

What is likely the easiest way to utilize passive solar energy is through the use of a system called “direct gain”. With a direct gain system, sunlight passes through windows where light is converted into thermal energy. The floors and walls then directly absorb and store that thermal energy. While the temperature of the home stays high, the heat will be retained. Once the temperature drops at night, that stored heat radiates through your home. You can also have a builder install plastic or metal water pipes inside a wall. When sunlight hits those walls, the water within the pipes heats up, which can then be pumped throughout the house as a heating source.

-Active Solar

For a more comprehensive green energy system, you can utilize active solar energy with solar panels on your home. Through the use of solar cells, sunlight is converted directly into electricity thanks to photovoltaic materials contained within the cells. That electricity can be used to heat, cool, and light your home. While there are tax rebates and other incentives available to people looking to switch to solar energy, the initial cost of installation can be quite steep, averaging anywhere between $27,000 to $36,000, depending on the size of the solar panels. That high price point would mean it could take around 12 to 15 years to recoup the money you spent with savings on your energy bills. While there are consistent strides to improving solar energy systems, changing the way they work and how they work, the efficiency of their energy conversion is only about 10 percent right now. Solar energy is something to keep an eye on for the future of green energy as it continues to evolve and develop.


Biomass can be defined as energy that is derived from living things, like trees and plants. Because biomass energy is renewable, it is a great option when you’re looking to make the switch to a more sustainable energy source. As it is natural, it is also better for both the environment and your health. Biomass heating systems take the energy that plants or other organisms absorb from the sun, and convert it into heat energy.

Not only is biomass more sustainable than traditional fuel oil, propane, and natural gas, it’s also cheaper. When you use a modern, large-scale biomass system, you’re burning cleaner than other systems that use fossil fuels, with a big reduction in the amount of carbon dioxide that is produced. A system that operates using wood chips will emit fewer pollutants than a wood stove. As biomass is burned, the only carbon it releases is what the plant would have released at its death. In contrast, when fossil fuels are burned, they release carbon that was once trapped inside the earth out into the atmosphere, increasing the overall carbon footprint you produce. Reports show that changing from natural gas to wood biomass, heating bills can be reduced by 29 to 57 percent, which can be considerable savings.

-Hydronic Heating

Although you may not be familiar with the term hydronic heating, it has actually been around for decades. The old radiator in your grandma’s house utilized hydronic heating. Modern hydronic heating systems are more sophisticated and operate with hot water that is piped through tubes that run under floorboards, through radiators, and along baseboards.

Hydronic systems utilize boilers which heat liquids with solar and geothermal energy. While most boilers heat water, other systems warm other liquids like antifreeze. No matter what the liquid is, it is pumped through plastic tubing into a heat exchanger, such as a radiator, where it is heated up for use through the house. Hydronic systems transfer heat in three ways: conduction, convection, and radiation. Conduction moves heat energy from object to object. Radiation transfers the heat energy through electromagnetic waves, which can be felt in the heat radiation you feel from a heat lamp. Convection, like what happens when you boil water, is when warm water rises while cold water sinks.


Unlike some of the systems listed above, absorption heating and cooling systems work in conjunction with solar power, geothermal power, or natural gas, with natural gas being the most commonly used fuel source. While absorption heat pumps work nearly identically to other heat pumps, there are two main differences. The first difference is an absorption heat pump is driven by a natural gas burner as opposed to electricity. The second, and possibly most distinct, is that an absorption pump utilizes a water-ammonia solution instead of a standard refrigerant. In the winter, that solution absorbs heat from the Earth, while the pump moves the heated liquid into the house to warm the air. The opposite happens in the summer.

Contact Integrity AC and Heating PhoenixThere are many more green heating and cooling technologies that we will be taking a closer look at in the future, but for now, we hope this gets your mind thinking about sustainable energy and what innovations we may see in the years to come. If you are interested in making a change to a more energy efficient HVAC system, call the Phoenix HVAC gurus at Integrity AC and Heating. We’ve got the experience and knowledge to help your home be as comfortable as you’ve always wanted. We hope to hear from you soon!