Should I Buy Dehumidifier Add-on for HVAC System? Is That Worth the Money?

Dehumidifiers and humidifiers are two separate accessories that can be installed as part of your central HVAC system.

Both components are effective:

• Dehumidifiers remove six to 12 gallons of water from the air in your home each day
• Humidifiers can make the air comfortable even in arid climates or when the furnace threatens to dry out your home in winter

This guide is mainly talking about whole-house dehumidifier add-on for HVAC system. For HVAC humidifier buying guide, you can read here: best whole house humidifier on the market

What is a Whole House Dehumidifier?

A dehumidifier removes moisture from the air in the same way an AC does with one difference.

First, here’s how they’re the same. Refrigerant cycles through a coil in the dehumidifier, pulling heat from the air and making the coil very cold. Water from humid air condenses on the coil, like water on the outside of a cold glass of iced tea. That water is drained away, so the air in your home gradually becomes drier and more comfortable.

The difference between a dehumidifier and AC is that the air is dehumidified but not cooled. Removed heat is returned to the air circulating through your HVAC system, not pumped to an outside unit where it is dispersed.

Whole-house vs Stand-alone Dehumidifier

A stand-alone humidifier is a lot cheaper, but it tends to remove moisture best from the air immediately surrounding it. That’s usually a basement, so has little impact on the air in the first floor and above. It’s possible to locate a dehumidifier on the first floor or above, but then you’ll have to empty the condensate tank frequently or run a hose to a drain, possibly in the basement.

A stand-alone unit costs a fraction of the price of a whole-house unit with installation, but the downside is hassle or trip potential on stairs that a hose is on. And stand-alone units are noisy when placed in living areas.

Whole-house dehumidifiers live up to their name – they do a better job lowering the humidity level throughout the home.

Why Install a Dehumidifier If You Have Central Air?

If you have an AC, and ACs remove moisture too, do you need a dehumidifier?

There are two possible answers to that question – No and Yes!

No: If you live in a climate without excessive humidity, then drying it further doesn’t make sense. Climates that don’t need extra dehumidification include not just desert areas of the US but most of the Northern Plains, Great Lakes and New England. Of course, if you have central AC and your home is comfy from spring through fall, you probably wouldn’t be reading this.

Yes: There are a couple of reasons you might answer “yes” to the question. The first is if your climate is muggy – warm and humid starting in spring and stretching into fall. In those climates, many central air conditioners cannot keep up with the need for dehumidification.

A second and related reason to say “yes” is that your central air conditioner is too big. Does that seem counter-intuitive?

When the AC is too big, it cools the house too quickly, and shuts off before it has removed much humidity from the air. A properly sized central air conditioner runs for longer cycles, so has the opportunity to remove more moisture.

The Cost Bonus of Dry Air

Dry air is more comfortable than muggy air. In fact, most people feel as comfortable in 78-degree air that has been properly dehumidified as in 70-degree air that is too humid. That means you can turn up your thermostat when the air is drier and cut your energy cost for the air conditioning. However, the dehumidifier also uses electricity, so your total energy bill will likely rise by 6% to 10% when running the dehumidifier.

Whole House Dehumidifier Costs

Dehumidifiers for the entire house are available in several sizes, so there is a range of prices. Installation varies by the type and difficulty of the work.

A stand-alone dehumidifier costs about $300. However, they are not as efficient, so the monthly cost to run them can be $30 or more. If the dehumidifier runs six months each year, then you would recover the higher cost of a whole-house unit in about 11 years through lower energy bills.

Is a Whole House Dehumidifier Worth the Cost?

If your climate doesn’t have high-humidity issues, then no, it is not worth the cost.

In humid muggy climates, the answer depends on whether you’re comfortable in spring, summer or fall. If you’re not, then talk with your HVAC technician about what a whole-house unit could do for indoor climate control and how much it would cost.

If you’d like answers to your questions and receive written estimates, consider our Free Local Quotes offer. The estimates are given by licensed and insured pros in your area that has been pre-screened for the experience. There is no cost or obligation to you.

The bottom line really is about comfort. If your home feels humid even when the AC is set to 72 or below, the air isn’t properly dehumidified. The two most effective solutions are:

1. Replace your current AC or heat pump with one that is properly sized. In very humid climates and weather, that still might not be enough.
2. Install a whole-house dehumidifier to complement your central AC.
3. If your AC is getting old, replace the entire system with one that includes a dehumidifier.

It makes sense to talk to a pro about the right solution for your home.

Written by Rene Langer

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.