How One Technology Keeps Your Food Cold and Your House Warm
Imagine having to drink tepid milk with your morning cereal bowl everyday, or having to go without milk in your icebox for a few days thanks to a missed delivery. In the past, preserving food by keeping it cool was an everyday concern for households that hoped to avoid food poisoning and food waste. Thankfully, most of us haven’t had to worry about that ever since the 1920s.
Now imagine having to go without heating fuel for a few days thanks to a missed delivery. Sound familiar? In the infamously cold winters of the American northeast, a convenient, reliable, and affordable source of heat for your home should be normal, as normal as a refrigerator in every home. Unfortunately, it isn’t.
Staying warm through the winter is still an everyday concern for American households even though the technology is well-researched and well-proven, and even though the technology is widely used in household refrigerators.
In this blog post, we’ll discuss how both refrigerators and geothermal heat pumps rely upon the same technology to provide modern comforts for you and your loved ones.
How Refrigerators Works
Chances are, you’ve noticed that standing next to your fridge on a hot day is less than ideal. If you stick your hand behind your fridge, you can actually feel the heat being released from the condenser as a fan blows air from your home over it! This is because a fridge works by transferring heat from the inside of your fridge to the outside, making your food cold and your house warm.
The refrigerant mixture that runs through your fridge absorbs heat from your food as it passes through the evaporator loops inside your fridge. This component is called the evaporator because the additional heat causes the refrigerant to turn into vapor.
Next, the fridge’s compressor compresses the refrigerant vapor by forcibly squeezing it into a small space. As you may have learned in your high school chemistry class, you can increase a gas’ temperature and pressure just by compressing it, so now the refrigerant becomes very hot.
Finally, it passes through the more spacious condenser loops outside your fridge, where the very hot refrigerant expands and comes into contact with the relatively cool air of your home. The refrigerant cools down by transferring the heat that it carried out of the food in your fridge into your home, and then the cycle can begin again.
How Geothermal Heat Pumps Works
Believe it or not, heat pumps function almost exactly the same way as fridges do. Simply put, Dandelion heat pumps pull heat from the ground to heat your home in the winter, and dump heat from your home into the ground to cool it in the summer.
The ground loops buried in your yard contain a water-based solution that absorbs the ground’s heat. This warm solution is circulated to the heat pump, which converts the solution from a liquid to a gaseous state. The compressor compresses the water vapor, causing it to heat up.
Meanwhile, the heat pump inside your home contains refrigerant mixture inside a loop, much like the loops of your fridge. The heat exchanger helps transfer heat from the hot, compressed vapor from the ground loops to the relatively cool refrigerant mixture at room temperature.
Now heated, the refrigerant mixture cycles heat back up into your home by transferring heat to the air. The newly heated air heats up your home by traveling through your air ducts, and the cycle continues.
The Science of Closed Loop Systems
In a “closed loop” system, nothing comes in, and nothing comes out – the mixture inside the loops simply circulates up and down to transfer heat. Meanwhile, “open loop” systems require a constant supply of water.
Your fridge operates on a closed loop system because it is easy to maintain – you never have to worry about refilling your mixture because it will never run out! Similarly, you never have to worry about refilling your Dandelion heat pump’s ground loops with more water because everything stays contained within the closed loop system.
Not only is it much easier, but it’s also much safer to use closed loop systems. The refrigerant mixture inside your fridge never contaminates your food, and the water mixture inside the heat pump’s ground loops never contaminates the groundwater below your home.
Closed loop systems also have an additional benefit. The Ideal Gas Law tells us that the pressure, volume, and temperature of gases are related, and since the volume of mixture inside a closed loop system never changes, then the temperature and pressure become indirectly proportionally related. In other words, this makes it easy to manipulate the mixture inside your fridge’s evaporator loops or inside your heat pump’s ground loops: we simply compress the mixture to heat it up or expand it to cool it down! So, as the mixture within the loop heats up, it also absorbs heat from and cools its surroundings.
Same Technology, New Approach
Regardless of climate or weather, the temperature underground remains the same and the science of heat transfer remains the same. Just as refrigerators work well in warm and cold climates, heat pumps work well too.
A common misconception around geothermal heat pumps is that they don’t stand a chance through the dead-cold winter of northern climates. Interestingly, people don’t usually wonder how refrigerators keep food cool in hot, southern climates. After reading this blog post, you hopefully understand how refrigerators work in Florida and geothermal works in New York.
Is geothermal a good option for your home?