SERVING 
If you’re suffering from high summertime humidity, you may be considering a dehumidifier for your home. But is a whole-house dehumidifier worth it, or should you just stick it out with your existing AC?
Let’s take a look at how a whole-house dehumidifier works, how much it costs, and some situations where it makes sense to invest in one. Afterward, you should be able to determine whether it makes sense to purchase a whole-house dehumidifier for your home.
How does a whole-house dehumidifier work?
A whole-house dehumidifier is a type of mechanical equipment that removes humidity from your home. It can operate between or during AC cooling cycles to remove the moisture that your air conditioner couldn’t. It essentially picks up the slack for an AC that doesn’t do a great job of managing humidity.
Inside a whole-house dehumidifier, there is a coil where the moisture condenses and drains to the outdoors. In this sense, the whole-house dehumidifier is kind of like an air conditioner except that it doesn’t lower temperature – it only lowers humidity.
- Between your HVAC system’s air return and the air handler: Air enters the dehumidifier via the HVAC system return where the unit removes humidity from the air stream. This dryer air then passes through your HVAC unit as it normally would.
- With a dedicated return for the dehumidifier: Here, the dehumidifier uses its own air return, dehumidifies the incoming air, and sends the dry air into your HVAC system’s supply plenum.
In our experience, the second method is the best way to install a whole-house dehumidifier because it doesn’t send the dry air back over the AC’s we evaporator coil. Either type of installation is valid, but we prefer the dedicated return method.
Here in Atlanta, where we have a very hot and humid climate, whole-house dehumidifiers can really help a lot of homeowners enjoy better indoor comfort during warmer times of year. After all, drier air just feels cooler!
Here in Atlanta, where we have a very hot and humid climate, whole-house dehumidifiers can really help a lot of homeowners enjoy better indoor comfort during warmer times of year. After all, drier air just feels cooler!
How much is a whole-house dehumidifier?
So, how much do these bad boys cost? The thing about whole-house dehumidifiers is that there isn’t a one-size-fits all type or installation. You have to buy a certain size dehumidifier depending on the size of your home. Also, the installation specifics will depend on how your ductwork is set up and where your air handler is located.
With those factors in mind, a whole-house dehumidifier usually costs about half as much as buying a new HVAC system for your home. In some cases, it will cost a little more than half of what you paid for your HVAC system.
So if it would cost $9,000 to install a new HVAC system today, buying a whole-house dehumidifier and having a pro install it will probably cost about $4,500 to $6,500. That’s not exactly cheap, but do the benefits make it worth the cost?
When a whole-house dehumidifier is definitely worth it
Now that we understand how these units work and how much they cost, let’s look at some situations where it absolutely makes sense to own one.
1. You already use one or more portable dehumidifiers
And you use them throughout your house. If you only use one in, say, the basement for short periods of time and not every day, then that’s fine. Keep it up. We’re talking about situations where you run the little portable ones upstairs and downstairs. You’re dealing with the noise they make, not to mention having to manually dump out the water they extract from the air.
Compared to portable dehumidifiers, whole-house dehumidifiers:
- Require less maintenance
- Last much longer
- Make virtually no audible noise
- Drain themselves, so you don’t have to do it
- Remove moisture from your entire house
- Operate more efficiently than most portable units
If you’re running little portable dehumidifiers all the time, then a whole-house dehumidifier will be a fantastic upgrade for your home. You will get all of the benefits you currently enjoy with practically none of the downsides.
2. Your air conditioner is too large for your home
Here in Atlanta, many residential air conditioning units are oversized. Contractors have a bad tendency to select system sizes based on insufficient information or just a single metric like square footage. As a result, they pick one that’s larger than it needs to be.
This causes problems, one of which is that the AC will satisfy the thermostat setting really quickly. Since all of your AC cycles are relatively short, there will be long stretches of time where the system doesn’t run at all.
That’s not good because you want your AC to run for longer cycles to remove humidity. In fact, the AC can’t remove much humidity from your home when it’s short-cycling. It’s why so many people feel hot even while the AC is set to “on” and they’ve got the thermostat at 73 degrees.
Enter the whole-house dehumidifier! With one of these units in your home, you can keep the relative humidity (RH) percentage down to a very comfortable 55% no matter how short your AC’s cycles are.
3. You can’t get your AC to remove enough humidity, even after making some adjustments.
If your air conditioner wasn’t properly commissioned by the installer or your evaporator coil is really dirty, it might not be removing as much humidity as it could.
There are several ways to make your AC remove more humidity, including:
- Keep the coil clean; regular AC maintenance will help you achieve this
- Lowering the fan speed to around 350 CFM; this is usually the right fan speed for an AC in our climate zone, but many systems are set up to run at higher speeds
- Installing thermal expansion valve, or TXV; the TXV is a bulb that attaches to your refrigerant line and allows your system to use more of the evaporator coil. The result is better removal of heat and humidity, but it only works if your system wasn’t using all of the coil in the first place.
- Properly charging your refrigerant; if the charge is off, the system won’t remove as much humidity as it could. Have an HVAC pro check your refrigerant charge.
If you do all of these things and you’re still suffering from high humidity, a whole-house dehumidifier is a sure-fire way to solve the problem.
4. You’re uncomfortable during the shoulder seasons
During the spring and fall, it’s often neither warm nor cold enough to run your HVAC system. As such, your AC isn’t there to remove humidity from the air. But while these seasons tend to have mild temperatures, they can still be uncomfortably humid.
A whole-house dehumidifier can help here. Since you configure it to remove moisture to a certain RH percentage, it will always keep your home dry and comfortable. The dehumidifier doesn’t care what the temperature is – it will just work!
While modern, variable speed air conditioning systems do a better job of dehumidifying your home, they can only do so while the AC is running. Since it’s still humid here in Georgia before and after summer, a dehumidifier can be a real godsend for keeping uncomfortable humidity at bay even when the AC is off.
5. You want a fresh air ventilation system for your home
In our climate zone, there are two types of mechanical ventilation systems that work well. One is an energy recovery ventilator, or ERV, a handy-dandy piece of equipment that we’ve written a lot about in the past.
The other is a whole-house dehumidifier with a connected fresh air duct. Some people call these systems ventilating dehumidifiers because, well, that’s what they do!
To install fresh air ventilation with your whole-house dehumidifier, we add a duct that connects to the outdoors before the return side of the dehumidifier. There will be a damper inside this duct, so you can control when you supply your home with fresh air. The outdoor air mixes with the home’s return air and passes through the dehumidifier, which removes the moisture.
As a result, you get dehumidification and fresh air ventilation. It’s a great ventilation solution for our warm, humid climate.
So, is a whole-house dehumidifier worth it for you?
It might be! If any of the above scenarios apply, then a whole-house dehumidifier is probably a worthwhile investment for your home.
Here in Atlanta, PV Heating, Cooling & Plumbing provides the most thorough, effective whole-house dehumidifier installations. To set up an appointment to discuss installing one of these units in your home, just call us at (404) 798-9672 or complete the form below!
