Mini-split systems have been widely used in HVAC for many years now. But they are just one solution available, so many people who are unfamiliar with them may wonder, why were split systems developed?
Shortly after traditional HVAC units were introduced in Japan around the 1950s, it was realized that the bulky and loud systems needed a redesign to meet the needs of smaller homes built close together. Developed as an alternative, mini-split systems were created as heating and cooling systems that allow the temperature of individual rooms or zones to be controlled. Today, there are a variety of mini-split systems on the market.
Before purchasing one, it’s important to understand the capacity of these units, and to find out: Do mini-splits dehumidify in heat mode?
As advancements in technology continue, the popularity of mini-splits continues to grow. The latest systems are more energy-efficient and run quieter than previous models. There are even units with a dry mode that claims to pull moisture without cooling a room. However, many mini-split manuals actually suggest that when in dry mode, the temperature should be set slightly lower than the room temperature to reduce humidity.
In theory, these systems seem to be a great fit to simplify installation for cooling, heating, and dehumidifying—but do they have the track record to prove their efficiency in all categories? Do mini-splits remove humidity? Let’s take a look.
So, does a mini-split dehumidify?
The truth: Yes & No…
Mini-split systems dry the air, but do they help with humidity control in indoor living spaces to keep it below the recommended 60% relative humidity?
These systems only dry the air, which limits their ability to remove moisture from rooms. Further, there are many variables to consider, so the answer isn’t cut and dry.
How many pints will be removed an hour/per day?
An average family of four produces 25 pints of moisture a day, through cooking, cleaning, laundry, showers, perspiration, even breathing, and more. Mini-split units “dry” four pints of water an hour on average (some less), and would have to run for over six hours non-stop to compensate for the added moisture. Yet, mini-split systems were not designed to run six hours non-stop. The main function is to cool – not dehumidify. Integrating an escape route for the added moisture is key.
Is dehumidifying the space left to the tenant to oversee and manage?
Unfortunately, residents are likely to choose personal comfort over property protection. Mini-split systems relinquish total control of the unit to the tenants. This allows the residents to regulate relative humidity settings, runtime of the unit, mode (cool, dry, heat), and even control if the unit is used at all. These choices ultimately determine the amount of moisture removed from the air.
How long will the dry setting on mini-splits run for?
Installing a mini-split with dehumidifier will keep tenants dry, thanks to a setting called “dry mode.” In theory, it sounds great to have a dry mode to remove humidity with only a small decrease to temperatures through a supplementary heating air. To achieve the best results, the best temperature for dry mode is around 24 degrees Celsius.
Are tenants aware when the relative humidity is too high?
Unfortunately, residents often don’t understand the negative side effects associated with excess moisture, and more often than not, can’t be relied upon to run their units accordingly.
So, will residents run dry mode continuously? The mini-split system should never be left in dry mode for long stretches of time. Just as excessive humidity can be uncomfortable, air that’s too dry can lead to its own set of issues. Running the mini-split in dry mode for a couple of hours should be more than enough to keep the humidity level under control.
What is dry mode on a mini-split?
Wondering, “What is dry mode on mini-split?” It typically offers three settings: “HIGH,” “LOW,” and “STANDARD.” An important feature of supplemental dehumidification is removing moisture, and a dehumidifier should help keep indoor relative humidity levels below 60 percent year-round. So do mini-split heat pumps dehumidify? Mini-split systems are capable of drying some of the added moisture during warmer months. Unfortunately, they are not designed to dehumidify in cold weather and will not pull moisture in the winter months. Dehumidification should run independently of cooling systems to ensure proper moisture removal. Mini-split systems do not determine relative humidity without an additional accessory, therefore control is extremely limited.
Wondering when to use dry mode on a mini-split?
Dry mode works best when the humidity is high—like on damp, sticky, or rainy days. However, on hot summer days, this setting isn’t as effective because it won’t cool the air significantly. Understanding the difference between the mini-split dry mode vs cool mode is important so you can keep your living space comfortable. On hot days, switching your mini-split system to cooling mode will help you stay cool and comfortable.
What is the operating temperature range of units?
These systems have indoor and outdoor units; the outdoor compressor will not work in temperatures below 50°. Humidity levels will vary throughout the year depending on the season. During the winter, people are home more frequently, producing even more moisture. It is common to find condensation forming on the windows during colder months. But signs of potentially dangerous levels of moisture are not always visual, and “humid weather provides excellent conditions for mold to grow,” according to the University of Florida. Mini-split systems do not provide dehumidification in heating mode.
What does the installation process entail?
One product, one installation, with one contractor, sounds ideal and appealing, especially for new construction apartments. However, if mini-splits are not pulling enough moisture daily, humidity will increase potentially causing property damage, remediation, the risk of litigation, and more. Mini-split systems cannot be relied upon to sufficiently maintain moisture levels and lower high humidity.
Due to so many unanswered variables, installing a supplemental in-wall dehumidifier is advantageous to remove moisture generated and trapped inside. Contrary to popular belief, an in or on wall dehumidifier can be easily installed in 30-45 minutes and doesn’t require a separate contractor.
As suggested by the Environmental Protection Agency (EPA), indoor relative humidity RH should be kept below 60 percent — ideally between 30 percent and 50 percent, if possible.
Key Factors of Effective Dehumidification to Consider:
- Easy installation
- Size of room or space in square feet
- Pints per day removed
- Coefficient of performance, measured in L/kWh
- Setting to control relative humidity levels
- Draining of collected condensate
- Placement of unit
- Energy efficiency of unit
- Residential behavior
The need for supplemental dehumidification in rental properties is best exemplified by seniors who become more sensitive to cold temperatures with age. Tenants will often leave thermostats at higher temperatures and a handful even refuse to run their units. Mini-split systems are unable to pull moisture from the air if they are not running. Limited income is also a factor for many renters, who would rather leave the unit off to save on their electric bill.
Truth:
Supplemental Dehumidification Independent of HVAC System is a Necessity to Remove Moisture Trapped Indoors
Understanding the difference between a mini-split dry mode vs a dehumidifier can help one achieve optimal comfort and air quality, especially if they are living in an area that is prone to high humidity.
The purpose of supplemental dehumidification is to remove moisture from the air and help lower relative humidity (RH) below 60%. Supplemental dehumidification will adjust RH levels indoors to compliment the capabilities of cooling systems. As the demand for efficient housing increases, sufficient ventilation is limited due to tighter envelopes. Since moisture is continuously added to the air indoors, supplemental dehumidification is essential to condense and remove moisture trapped in your property. Innovative Dehumidifier Systems is available to guide you through the entire process and put the control back in your hands. Learn more about the IW-25-5 In Wall/ON Wall Dehumidifier with Bi-Polar Ion Generator.
