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Revised:
December 2nd, 2021
It seems as though Americans are just now discovering ductless mini-splits, but in fact, they were invented after the end of World War II.
Air conditioning manufacturers in the U.S. were hoping to capitalize on Japan’s need to cool off in the summer. That’s when air conditioners were first introduced to Japan.
But Mitsubishi’s early air conditioning systems could be used only rarely because Japanese homes were small, thin-walled, and tightly clustered together. Ductwork would have been invasive and expensive. In 1959, Mitsubishi succeeded in inventing ductless mini-split heat pumps to take care of Japan’s desire to cool off.
They’re called ductless because, as the name implies, they don’t require any ducts. The head (or evaporator) mounts on walls, floors, or even ceilings, and they connect to a condenser that sits outside.
Like central air conditioners, these have a split design - one piece inside, one outside. “Mini” refers to the fact that the heads are smaller than traditional AC or furnace equipment.
In the last seven years, the U.S. ductless mini-split market has seen a 221 percent growth rate. And it is expected to continue to grow at a rate of 20 percent or more per year.
Already at Fire & Ice, we’ve installed hundreds of units, and have answered thousands of questions about ductless mini-splits. Homeowners who have heard of them wonder about the ease of installation, the benefits they offer, and the cost. In this article, we’ll take a closer look at the Mitsubishi NTXMPH Pro series heat pump outdoor unit coupled with the Nv Series WPH indoor wall-mount head.
By the end of this article, you’ll know about the many benefits of this ductless mini-split system and can see if it might be right for you. You’ll also know enough about them to speak to an HVAC salesperson about your next step with confidence.
Mitsubishi WPH Ductless Mini-Splits Capacities
Each ductless or ducted indoor unit is connected to the outdoor unit using two small refrigerant pipes and wiring typically routed through a three-inch opening in the wall. The indoor and outdoor units communicate with each other constantly, relaying current conditions and adjusting performance to maintain the desired temperature.
The WPH line comes in five heating/cooling capacities:
- NTXWPH06B112AA
- NTXWPH09B112AA
- NTXWPH12B112AA
- NTXWPH15B112AA
- NTXWPH18B112AA
The “06” in the first listing refers to the cooling capacity, meaning that it can cool up to 6,000 BTU/H (British Thermal Units per Hour). The last in the list can cool up to 18,000. (A BTU is a unit of heat; it is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. A 6,000 unit is equal to one-half ton; 18,000 is one-and-a-half tons. ) If you need to conditioner the air in a larger space, Mitsubishi has dozens of other options.
And to determine the size, you’ll need your HVAC salesperson to do a Manual J Load Calculation, a series of measurements that include different parameters of your home. This is not just the square footage of a home. It includes size and number of windows, quality of insulation, and a host of other factors.
A ductless mini-split system can include up to eight heads, meaning that these units can heat/cool up to eight rooms from a single outdoor unit. A typical installation would more likely be anywhere from a single head to up to five. Each head would be able to heat/cool one room, or zone.
When we talk about zoning, we’re talking about how homeowners can heat one room to 72 degrees, but a lesser used room might be set at 68. Five heads mean that five different rooms can have their temperatures at five different settings. Zoning allows operation based on room occupancy and temperature needs, which saves energy and reduces your electricity bill.
Mitsubishi WPH Ductless Mini-Splits Features
Features include:
3D i-see Sensor
Dual vane with multiple airflow settings
Triple filtration
Dual Barrier Coating on heat exchanger
ElectroStatic anti-allergy enzyme filter
Variable-speed blower
Remote with kumo cloud app
SEER rating above 30
Quiet operation
One of the main benefits of ductless mini-splits heat pump systems comes down to utility savings. With their energy-efficient technology, heat pumps can lower your home’s total cost of ownership and monthly utility expenses.
Their SEER rating can reach as high as 33.1, which is dramatically better than conventional systems. A high-efficiency air conditioner’s SEER rating can get up to 20 or so. The higher the rating, the more efficient it is.
They run quietly. The inside part of these ductless mini-splits can operate as low as 19 decibels. (A whisper is 30 decibels.) You’ll barely realize when they kick on.
They come with Mitsubishi Electric's dual barrier coating, which protects the unit from the ill effects of dirt and dust. This gives the units the power to work at full performance. The reduction in dirt also means the bad smell and odors are reduced.
Even in cold climates, modern heat pumps can keep your family comfortable. Mitsubishi heat pump systems can provide up to 100 percent of heating capacity at outside temperatures as low as 5° F, and can provide some warmth at -13° F - even without auxiliary heat.
The inverter-driven compressor continuously runs, adjusting speeds and capacity as needed to meet the setpoint temperature of a zone (or specified area). This method of operation reduces power consumption by using only the exact amount of energy required to maximize comfort.
The variable-speed blower disperses the right amount of heating and cooling into spaces. Single-stage furnaces and air conditioners have two settings: on, which means 100% on, and off. There are two-stage models, but a variable speed is the top of the line. It can keep the temperature of the room at exactly what the thermostat tells it to.
It’s more energy-efficient, since it doesn’t have to start from zero when the call comes for heat. Tiny adjustments are easier on the system than large ones. It constantly filters the air and dehumidifies since it’s always running, creating healthy, clean air all the time.
Comparatively, many conventional central systems use a fixed-speed compressor that is either completely shut off or fully on at capacity. This can lead to large temperature swings and wasted energy, which affects your home’s overall comfort and utility costs.
The WPH line of wall-mounted units creates personalized home comfort with multiple airflow settings. In the winter, you can send the warm air down so that it stays in the room longer. If you want to cool off quicker, the vanes can be adjusted so that air blows on you.
The WPH features industry-leading filtration for a healthier home. It traps dust and other airborne impurities so that you can breathe easier. (The filter does require some periodic maintenance to continue running at peak performance. The filter is easy to remove, wash under a faucet, dry, and reinstall. Cleaning it leads to cleaner air and a unit that will run more effectively.)
The 3D i-See Sensor uses infrared technology to sense your heat signature, directing cool and warm air where it’s needed most, and helping to save you even more on your energy bills. It scans the room and makes adjustments based on hot and cool spots. It can even detect when the room is unoccupied.
You can control all these features with the kumo cloud app for the ultimate home comfort.
Who Would Benefit Most From a WPH Ductless Mini-Split?
We frequently propose a single-zone heat pump for master bedrooms, garages, or bonus rooms above the garage. These rooms are tough to heat or cool, and people tend to spend a lot of time in them. Without ductless mini-splits, you’d have to heat the entire house to get adequate heat to them. They provide the ultimate temperature control. (It’s important to remember that they heat and cool only one room per head.)
They are also effective in removing humidity in the summer, which can give woodwork - wooden floors or musical instruments - a longer life. When the indoor air is at its mugginess, the rooms being cooled will feel much better.
This might not be the best option for you if you’re looking for a whole-home heating and cooling solution, you might be better off looking at an air conditioner/furnace combo, or a heat pump.
Take the Next Steps Towards a Mitsubishi Ductless Mini-Split
A ductless mini-split with one head or multiple ones is no small investment. But for a house with no ductwork, or one with problem-area rooms, it can be the perfect option.
If you’re still interested in a ductless mini-split system and think it may be part of a solution for your home, check out our articles that break down the cost of mini-splits
Once you do that, if you’re in the Columbus, OH area, reach out to us to schedule your free in-home estimate where we’ll answer any questions you have and help you settle on a solution to meet your needs.
Read more:
Ductless Mini-Splits: A Comprehensive Cost Breakdown
