With Ductless Heat Pumps, Efficiency and Maintenance Go Hand in HandPublished on: April 30, 2014
If you’re one of the growing number of homeowners who are turning to ductless heat pumps for home heating and cooling, read on to learn how efficiency ratings and regular maintenance can maximize your investment in comfort and energy savings season after season.
Ductless Heating and Cooling
Ductless heat pumps are refrigerant distribution systems that deliver efficient and continuous heating and cooling with sleek point-of-use air-handling units (AHU) installed immediately inside the living spaces. This offers homeowners great advantages for comfort, low energy bills and good indoor air quality compared to typical central heat pump systems. These are the primary components of ductless heat pumps and their basic functions:
- Indoor AHU: The indoor AHUs house the heat-exchange coil, multi-speed fan, air filtration system, sensors and condensate drainage. They are mounted on a wall or ceiling, or concealed from view behind the wall, ceiling or floor. Air from the living space is pulled into the AHU and through the air filters. This removes particles and contaminants from accumulating on the components, which would affect efficiency. As the air is pulled across the heat-exchange coil, heat energy is transferred to the air (Heat mode) or to the coil (Cool mode).
- Outdoor unit: The outdoor unit is mounted to a firm surface, such as a small concrete slab, a flat roof or mounted to the home shell. The outdoor unit houses a heat-exchange coil, compressor, fan and other components. Airflow is pulled into the unit and across the heat-exchange coil, like the indoor AHU.
- Conduit: A thin conduit contains the refrigerant lines, condensate tubing and power cable. It connects the outdoor unit to the indoor AHUs. The conduit enters the home shell through a relatively small hole (3 or 4 inches), and is routed through inconspicuous spaces inside walls, the attic and/or crawl space.
Efficiency Ratings Matter
The efficiency ratings of ductless heat pumps are quick indicators of how efficient your new system is going to operate. This information can help you select a system that is suited to your project and energy budget goals. It is also valuable information to help you design a multi-split system (multiple AHUs installed in multiple zones). Keep these points in mind when shopping and designing your ductless system:
- Comparing systems: You may have seen the bright yellow EnergyGuide labels before, which display the efficiency ratings of various home comfort systems and home appliances. The EnergyGuide label can quickly tell you a particular model’s efficiency, and how the model compares to other systems in regards to estimated annual operating cost (this is based on the national average of energy prices), system size, the estimated annual energy consumption based on average usage and an easy-to-read line graph that provides the estimated annual energy costs of similar systems. You can use the average energy prices in your region of the Southeast U.S. to get a more accurate figure for operating costs.
- Lifetime cost: When you’re shopping for ductless heat pumps, your investment involves much more than the number on the price tag. The lifetime cost of ductless heat pumps is the sum of the purchase price, installation, estimated energy cost over its lifetime and the estimated cost of maintenance and repairs for the average lifespan of the system. The lifetime cost analysis performed by your HVAC professional allows you to compare the actual cost of your investment.
- Return on investment (ROI): If you are installing a high-efficiency ductless system, you’ll want to know the ROI to see if it is a better value than a lesser efficient model. The point at which monthly energy savings for the more expensive high-efficiency system pays for the lifetime cost differential is the point your new system is literally paying for itself while you enjoy superior performance and home comfort.
- Regional weather: The weather in your region of the Southeast U.S. is important when comparing efficiency ratings. For instance, if you live in Florida’s Treasure Coast, you will be more concerned with cooling efficiency. If you live in East Tennessee, heating and cooling efficiency may be equally important. Special installation considerations are necessary, too, for the outdoor unit and indoor AHUs. For instance, in the Treasure Coast, you may opt for “soft” barriers (shrubbery and vegetation) to help shield the outside unit from leaves and other debris. In East Tennessee, you may opt for a “hard” barrier, such as an awning or wall mounting option, to help shield the outside unit from the occasional snowfall and freezing rain. (Protecting the outside unit ensures free airflow.)
- Project specifications: If you are designing a ductless multi-split installation, efficiency ratings and sizing should be at the forefront of system design. For instance, the indoor AHU installed in frequently used living areas should be high efficiency. In a seldom used guest room, you may opt for a less efficient and less expensive AHU, since it won’t be used often. If you are installing a whole-house ductless system as a system replacement or for a new energy efficient home, a high-efficiency modular configuration (multiple outdoor units and indoor AHUs) delivers controllable and independent zoned efficiency and comfort, and good indoor air quality throughout your home. In fact, it’s often less expensive to install a whole-house ductless system for new construction than it is to install a central ducted system, and you save valuable square footage.
Look for the blue Energy Star logo to help you quickly identify energy efficient ductless heat pumps. Energy Star Certified ductless systems have met strict efficiency criteria as established by the U.S. Department of Energy and Environmental Protection Agency. To earn the blue Energy Star logo, the following criteria must be confirmed:
- The product offers extra features and delivers performance greater than that of lesser efficient products in the same category.
- The ROI of the higher efficiency product must be achieved within a reasonable amount of time.
Consider ductless heat pumps that have earned Energy Star’s Most Efficient designation, which was introduced as a new category in recent years. You can be assured that systems earning the Most Efficient status are designed for performance, efficiency and nice ROI by meeting a minimum of 18 SEER (Seasonal Energy Efficiency Ratio), and minimum of 9.6 HSPF (Heating Seasonal Performance Factor).
SEER: Cooling Efficiency
The SEER number represents the cooling efficiency of any heat pump or A/C system. The higher the number, the greater cooling efficiency. SEER rating is calculated by the estimated cooling output during the course of the cooling season to the estimated electricity consumed. Look for Energy Star Certified heat pumps with greater than 20 SEER if you live in warmer regions of the Southeast U.S.
HSPF: Heating Efficiency
Today’s ductless heat pumps offer homeowners ample heating power and efficiency. Where central heat pump systems typically have a balance point around 32 to 38 degrees, ductless systems provide comfortable heating when outside temperatures dip to as low as -4 degrees.
Similar to SEER, the HSPF of ductless heat pumps is an estimation of heating output to electricity consumed during the heating season. Look for ductless heat pumps with around 11 HSPF if you live in cooler regions of the Southeast U.S.
CEE: Consortium for Energy Efficiency
CEE (Consortium for Energy Efficiency) is an organization of energy-efficiency experts across the U.S. and Canada. This organization engages the industrial, commercial and residential design, manufacture and construction industries to promote energy savings through programs, initiatives and products. If the ductless heat pump you are considering displays a CEE rating, look for CEE Tier 3 Advanced category.
Professional Preventive Maintenance
Ductless heat pumps need annual preventive maintenance to maximize efficiency ratings for peak performance, and for your home comfort. These are some of the key points and inspections your HVAC pro performs:
- Airflow: The indoor AHUs and outdoor unit are inspected for free airflow. Fan speeds are checked. The air filters are removed and cleaned. Any debris on and in the outside unit is cleaned and removed.
- Refrigerant: Refrigerant charge is tested for optimal levels, which is typically an ounce or two within manufacturer specifications.
- Coils: The indoor and outdoor heat-exchange coils are deep-cleaned to remove debris and to help prevent mold growth. Any debris or contaminants on the coils reduce efficiency. The coils are inspected for any refrigerant leaks.
- Power: Controls are inspected for function, Heat, Cool, Dehumidification, Defrost and Auto modes. Timers and other modes are checked.
- Drainage: Clear condensate drainage is critical with ductless heat pumps. If components are kept clean, the chance of clogging is reduced. The condensate line is checked and treated to prevent algae and bacterial growth.
- Conduit: The conduit is inspected at the entry point and inside the home for damage and water leakage.
Work with a reputable contractor that can help you select and design the best ductless system for your needs, and provide ongoing maintenance and care. For more information about ductless heat pumps and efficiency, please contact us to speak with a certified ductless systems specialist near your part of the Southeast U.S.