Dehumidifiers vs ERV in Florida

Q. What is a whole house dehumidifier?

A. A whole house dehumidifier is a piece of equipment that brings in air from your home, extracts moisture from the air and then disperses this air back into the return ducting of your central air conditioning system, therefore providing dry air to the air conditioning system to distribute throughout the home.

Q. How does a whole house dehumidifier extract the moisture from the incoming air?

A. The device has a built-in fan, compressor, and evaporator coil just as a typical air conditioning unit, they are just miniature versions. As the fan pulls the moist air into the dehumidifier across the cold coil, the moisture is collected on the surface of the cold coil, just as the moisture in the air is drawn to the surface of a cold can. The moisture then goes into a drain line and out of the home. The drier air is now pushed from the dehumidifier to the return of the air conditioning system, where the air conditioning unit cools the air and distributes the dry air throughout the home.

Q. How does a whole home dehumidifier differ from an ERV?

A. An ERV, also known as an energy recovery ventilator, simply allows you to pull fresh air into your home and use the air inside your home to help dry the incoming air without the use of a compressor or cooling coil. As you can imagine, this type of dehumidification is very limited in terms of capacity with what we experience in the coastal Florida climates. The main difference between the two devices is that an ERV uses what is called a desiccant wheel (think of a dehydrated powder) to absorb and transfer moisture, whereas a whole house dehumidifier monitors humidity and removes the humidity by means of a compressor and coil.

Q. I heard someone say I should introduce “fresh air” into my home. What does this mean, and isn’t the air outside very humid?

A. There have been multiple studies on the subject, and about every expert agrees that indoor air contains higher levels of dust, mold, allergens, and overall is just less healthy than outdoor air. In the areas we live in we have no worry of smog or those type of contaminants, therefore introducing outside air is of great benefit. But, we have to remove humidity in order to introduce outside air. The version of dehumidifier we use has a fresh air provision. Therefore we are introducing fresh air and dehumidifying it every time the dehumidifier is in operation.

Q. How much does it typically cost to run the dehumidifier?

A. I have one installed in my home, and frankly, I didn’t even notice the difference in my power usage. From my experience with installing these in many homes, the average cost to operate the machine is $5 to $10 a month, unless you have excessive moisture problems. What I did notice though, is that my house most of the year is 40% humidity inside, which feels great.

Q. What are the benefits of lowering the humidity in my house?

A. There are too many benefits to list, but, the two primary ones are, number one, viruses, bacteria, and mold do not thrive in a lower humidity environment, therefore making your entire home healthier for you and your family. Secondly, it allows you turn your thermostat to a higher setting as you will feel much cooler with the lower humidity, making it easier to sleep at night.

Q. How much moisture can a dehumidifier remove per day?

A. The model we install most and I have in my home can remove approximately 120 pints of water in a 24 hour period, in other words about 15 gallons per day in moisture that is already in your home currently.

Q. What controls the dehumidifier?

A. Much like an air conditioning system, there is a thermostat we install dedicated to the dehumidifier that turns the dehumidifier on or we can install a central controller that engages the air conditioner and the dehumidifier at the same time. It depends upon the type of air conditioning system you may have as to which choice would be optimum.

Q. Lastly, this all sounds great but how much does a typical whole dehumidifier cost installed in my home?

A. That is a difficult question to answer due to various dehumidifier sizes, applications, ducting required, etc. The typical cost range for one installed in an attic is $3000 to $6000 depending upon a list of variables.