How Does Cool Down Work?
Why are basements cool?
If you’ve ever been in a home with a basement you know that in the very hot summer months, the basement is the best place to escape the heat. Why? The answer is actually pretty simple. The temperature of the earth at a depth below 4 feet is typically around 50 degrees fahrenheit all year long, even in the cold winter months when air temperatures can be negative, or in the summer months when air temperatures can be 90 degrees fahrenheit or higher. Given that the temperature of the earth is approximately 50 degrees below 4 feet, and a typical basement has a depth of approximately 8 feet, that means that the walls and floor of the basement, otherwise known as the foundation, exchange heat energy with the ground creating a cooling effect in the basement.
If a home has an average 850 square foot basement, that means that 850 square foot of basement floor space plus several hundred square feet of the basement walls are in direct contact with the ground – creating a natural heat sink, meaning that the warm temperatures from the home move into cool ground under and to the sides of the basement walls and floor.
With this principle in mind, we at Cool Down wondered why don’t people use this naturally cool temperature in the basement to cool the rest of their home in the summer? And so, Cool Down was born.
Now, how does Cool Down work?
A Cool Down system works by combining 4 key elements:
A heat exchanger
Two dampers that fit into the home’s existing ductwork
Temperature controls to measure living space and basement temperatures
A return duct from your living space
Cool Down cycles between two modes of operation:
Whenever the basement is >5° cooler than the conditioned space the system is in active cooling mode.
This means the AC condenser deactivates (if there is one), the in-line damper closes, the heat exchanger supply and return dampers open, and the heat exchanger activates. During this phase the cold temperatures from the basement are used to cool the house and at the same time heat from the conditioned space is directed into the basement where it is dispersed into the ground via the floor and walls of the basement.
If at any time the temperature in the basement is <5° cooler than the conditioned space the Cool Down system enters an inactive recharging mode.
During this phase the AC condenser activates (if there is one), the in-line damper opens, the heat exchanger supply and return dampers close, and the heat exchanger deactivates. This means the cold temperatures are able to build up in the basement again as heat continues to disperse into the ground until the basement is once again >5° cooler than the conditioned space. At that time the system cycles back into active cooling mode.
System Performance on Moderate and High Temperature Days
Average system performance in Upstate New York.
High Temperature Day
Above you’ll notice the Cool Down Air Conditioning System performance on a high temperature day. In this example, when the outdoor temperature was 85° and the indoor temperature was 80.1° the Cool Down Air Conditioning System was able to lower the living space temperature to 70.9°.
Moderate Temperature Day
Above you’ll notice the Cool Down Air Conditioning System performance on a moderate temperature day. In this example, when the outdoor temperature was 75° and the indoor temperature was 73° the Cool Down Air Conditioning System was able to lower the living space temperature to 67.8°.
What are the benefits of a Cool Down system?
I Already Have Central AC
If your home already has a central cooling system, with an outside condenser, a Cool Down system can significantly reduce your cooling bills by offsetting the need of your condenser to turn on, saving you an estimated 67% a year on your cooling bills.
I Don’t Have Central AC
If your home doesn’t already have a cooling system, a Cool Down system can be a great way to get low-cost cooling at a fraction of the cost of a traditional central cooling system.
If you have any additional questions about Cool Down, please don’t hesitate to schedule a consultation with our team, or simply call us at 845-419-3361.
