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Mini Split 2 Zone

A mini split 2-zone system is an ideal solution if you want separate temperature control for the main living area and an addition, attic conversion, or basement in your home. The condenser unit is installed outside and linked to two air handlers inside the house.

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Each zone has its thermostat to control the temperature for that area. Mini-splits are very energy efficient since there is no ductwork to lose energy. They are also ideal for homes where installing or extending ductwork is not practical.

How Much Does It Cost to Install a 2-Zone Mini Split?

Installing a mini split 2 zone system in your home typically ranges from \$2,500 to \$5,000 for the equipment and installation. The final cost will depend on several factors:

Equipment needs

  • A basic system with a small indoor unit and the compact outdoor unit starts at around $574. Larger, more powerful systems with additional indoor units cost $1375-$2,000 or more.

Brand and efficiency

  • Higher-end brands and systems with a higher seasonal energy efficiency ratio (SEER) rating, like 18 SEER or above, will be on the higher end of the price range. Basic systems may start around $724, while a high-efficiency system could be $1,372-$2,000.

Additional indoor units

  • Each additional indoor unit, called a "zone," will increase the total cost by $500-$1,500 depending on its size and features. Two-zone systems should be adequate for most homes.

Installation requirements

  • Complex installations where extensive wiring or ductwork is needed will add to the total cost. Simple installations start around $500-$1,500.

Contractor rates

  • Rates in your local area will also affect the installation fees. National averages are $75-$100 per hour, but rates in some areas may be higher.

Added features

  • Things like Wi-Fi connectivity, air filters, thermostats, and zoning controls will increase the price. Basic systems typically include a standard thermostat for each zone.

What Size Breaker Do You Need for a 2-Zone Mini Split?

For most 2-zone mini split heat pump systems with efficiency ratings of 15 SEER or higher, a double pole 30 amp breaker should suffice. However, it is best to check the requirements listed in the product specifications for your exact model. The breaker must be properly rated for the voltage of your unit, which is typically 240V. An undersized breaker can trip frequently, causing the unit to turn off, while an oversized breaker will not provide adequate protection.

Electrical Requirements for Indoor and Outdoor Units

  • In some cases, the indoor units may require their dedicated breakers, in which case two double pole breakers of the size recommended for a single zone unit may be needed. The outdoor unit will specify the minimum amperage for the main power supply breaker. The indoor units will list their amperage draw in their specifications as well.

Breaker Sizing Considerations for Line Set Length in Mini Split Systems

  • The breaker size also depends on the length of wiring needed between the outdoor and indoor units. Longer line sets require larger breakers to account for the voltage drop over the additional distance. It is best to follow the recommendations in the installation manual for your mini split model regarding appropriate breaker sizing for different line set lengths.

How to Choose the Right Breaker for Your 2 Zone Mini Split

Calculate the Minimum Breaker Size

  • The minimum breaker size for a 2 zone mini split is typically 30 to 50 amps. To determine the exact size needed for your unit, check the specifications in the installation manual or on the nameplate on your outdoor condenser. This will list the maximum overcurrent protection device (OCPD) rating in amps which is the minimum breaker size. For most 2-zone systems in a residential setting, a 40 or 50-amp breaker should suitably power the unit.

Choose a Slightly Larger Size

  • Once you know the minimum size, choose a breaker 5 to 10 amps larger to allow for compressor start-up surges and ensure continuous operation. For example, if your mini split calls for a minimum 40 amp breaker, install a 50 amp breaker. The slight oversizing will prevent nuisance tripping.

Use a Time-Delay Fuse or Circuit Breaker

  • Choose a time-delay or circuit breaker specifically rated for air conditioning applications. Standard fuses and breakers may trip prematurely due to the large current draw when the compressor starts. Time-delay types are designed to handle the surge on start-up before tripping at the amperage rating.

Double Pole Switch

  • For most residential mini splits, install a double pole circuit breaker or switch. This means both the red and black power wires connect to the same breaker, ensuring the entire unit loses power if the breaker trips. A double pole breaker helps prevent damage to the compressor from unequal power.

Sizing Your 2-Zone Mini Split

Calculate Your BTU Needs

To determine the right BTU for your space, measure the square footage of each zone and add them together. As a rule of thumb, you'll want:

  • About 9,000 to 12,000 BTU to cool a 150 to 300 square foot room.
  • 12,000 to 18,000 BTU for 300 to 450 square feet.
  • 18,000 to 30,000 BTU for 450 to 700 square feet.
  • 24,000 BTU or more for larger spaces.

It’s best to slightly oversize your mini split by about 10% to ensure adequate cooling on the hottest days. An undersized unit won’t cool properly and will have to work harder, reducing its lifespan.

Choose Your Tonnage

Mini-split BTU ratings correspond to a unit's tonnage, which refers to how much heat it can remove in one hour. One ton equals 12,000 BTU. So a 1.5-ton unit provides 18,000 BTU, a 2-ton unit is 24,000 BTU, and so on. In general, a mini-split can cool:

  • About 500 to 700 square feet per ton.
  • 600 to 800 square feet for a 1.5-ton unit.
  • 700 to 1,000 square feet for a 2-ton unit.
  • 1,200 square feet or more for a 3-ton system.

How to Properly Vacuum and Maintain Your 2-Zone Mini Split

Clean the Air Filters

  • The air filters are one of the most important parts of your mini split to keep clean. Clogged, dirty filters reduce airflow and efficiency, and can even damage the unit. Check your filters once a month and vacuum or replace them if they look dirty.

Vacuum the Indoor Unit

  • Use the brush attachment on your vacuum to thoroughly clean the surface of the indoor unit, including the vents, grills, and front cover. Pay extra attention to any cracks and crevices where dust can build up. Remove the front panel if possible to access the fan and coil, vacuuming away any dirt or lint.

Clean the Drain Pipe

  • The drain pipe removes excess condensation from your unit. Use a vacuum with a hose attachment to suction out any clogs or blockages in the drain pipe to prevent water overflow issues. It's also a good idea to pour some diluted bleach down the drain pipe every few months to prevent the growth of mold and mildew.

Outdoor Unit Maintenance

  • Don't forget about the outdoor unit. Use a garden hose or wet/dry vac to remove dirt, leaves, and debris from the fins of the condenser coil and fans. Straighten any bent fins with a fin comb tool. Wipe down the exterior cabinet and clear away any plants, mulch, or other materials touching the unit for unobstructed airflow. Lubricate the fan motors if needed.

Owning a Two-Zone Mini Split Heat Pump System Offers Enhanced Energy Efficiency and Comfort

As a homeowner looking to improve energy efficiency and comfort, a mini split heat pump system with two zones is an excellent option to consider. With separate temperature controls for different areas of your home, you'll be able to heat and cool spaces according to your needs. Do some research on the best brands and models for your local climate to make the most of this efficient technology. A mini split heat pump can be an ideal solution for balancing comfort and cost in your home.

Contact The Trade Table!

Contact The Trade Table!

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