Converting to Heat Pumps

Overview

Heat pumps are an efficient and cost-effective alternative to traditional heating and cooling systems, as they use electricity rather than fossil fuels to generate heat. Relatively easy to install and maintain, they are also a good choice for homes that do not have access to natural gas. They work by transferring heat between the inside and outside air, and they are an efficient and cost-effective alternative to traditional heating and cooling systems.

Air-to-water heat pumps transfer heat between the inside air and a water-based heating system, such as a radiator or underfloor heating system. They are more efficient than air-to-air heat pumps, as water has a higher heat capacity than air, but they are also more expensive to install and maintain.

Ground-source heat pumps transfer heat between the ground and the inside of a home or building. They use a series of underground pipes, known as a ground loop, to exchange heat with the ground. They are highly efficient for both heating and cooling, but also the most expensive type to install.

Air-to-air heat pumps are the most common, affordable and easiest to install type heat pump.have two main components: an outdoor unit and an indoor unit. The outdoor unit contains a compressor and a condenser, which are responsible for compressing and releasing the refrigerant. The indoor unit contains an evaporator, which is responsible for absorbing heat from the air and transferring it to the refrigerant.

When the heat pump is in heating mode, the outdoor unit draws in air from the outside and uses the refrigerant to transfer the heat from the air to the inside of the home. The indoor unit then circulates the warm air throughout the home using a system of ducts.

When the heat pump is in cooling mode, the process is reversed. The indoor unit draws in warm air from the home and uses the refrigerant to transfer the heat from the air to the outside. The outdoor unit then releases the heat into the outside air.

Why Heaters are the Future of Cooling - Vox

"Experts call it the 'cold crunch' As temperatures rise in regions that historically haven’t needed indoor cooling, global demand for air conditioning units is expected to skyrocket. Indoor cooling is already the fastest-growing use of energy in buildings. But the emissions associated with cooling buildings are still tiny compared to the emissions from heating them — and that's because while air conditioning uses electricity, our heat is still largely generated by burning fossil fuels. The way we heat our homes and buildings is one of the biggest contributors to climate change. But a solution may actually come from the rush of consumers looking to buy AC for the first time. They're a huge potential market for a different kind of system — the electric heat pump."

How a Heat Pump Works | This Old House

"This Old House plumbing and heating expert Richard Trethewey uses a mock up and props to show host Kevin O’Connor the mechanics of the latest state of the art heating and cooling system. Heat pumps have compressors, valves, and fans that regulate speed and opening so a system can evenly maintain itself and keep temperatures steady to the exact degree."

Advantages

1. Climate: Heat pumps are most efficient in moderate climates where the temperature doesn't frequently drop below freezing. Air-to-air heat pumps, in particular, may experience reduced heating capacity in extremely cold conditions. It's important to consider your local climate and ensure that heat pumps can provide sufficient heating during colder months.
2. Insulation and Air Sealing: Proper insulation and air sealing are crucial for optimizing the performance of heat pumps. Good insulation helps retain heat in the winter and keep your home cool in the summer, reducing the workload on the heat pump. Well-sealed windows, doors, and ducts prevent air leaks, ensuring that the conditioned air remains inside the home. Prioritize insulation and air sealing measures before installing a heat pump for optimal efficiency.
3. Energy Efficiency: Heat pumps are known for their energy efficiency, but it's important to consider the efficiency ratings of different models. Look for heat pumps with higher Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF) ratings. Higher ratings indicate better efficiency and can lead to lower energy consumption and utility costs.
4. Heat Pump Sizing: Proper sizing of a heat pump is crucial for efficient operation. An oversized heat pump may cycle on and off frequently, leading to increased energy consumption and reduced comfort. Undersized heat pumps may struggle to meet the heating or cooling demands of your home. Consult with HVAC professionals to determine the appropriate heat pump size based on factors such as square footage, insulation, and climate.
5. Supplementary Heating/Cooling: In regions with extremely cold climates, it may be necessary to have a backup heating system, such as a furnace, for particularly cold days. This backup system can supplement the heat pump when it struggles to extract sufficient heat from the outdoor air. Consider the need for supplementary heating or cooling methods based on your local climate.
6. Maintenance and Service: Heat pumps require regular maintenance to ensure optimal performance. This includes cleaning or replacing filters, checking refrigerant levels, and inspecting components for wear and tear. Additionally, consider the availability of qualified HVAC professionals in your area who can provide regular servicing and address any potential issues that may arise.

Mini-split heat pumps

Mini-split heat pumps are efficient heating and cooling systems consisting of an outdoor unit (condenser) and one or more indoor units (evaporators). They are called "mini-splits" because they don't require ductwork and can be used to heat or cool individual rooms or zones in a home. These units are connected by a refrigerant line, electrical wiring, and a conduit that houses the refrigerant tubing, power cables, and a condensate drain.

The refrigeration cycle, fundamental to mini-split heat pump operation, begins with the outdoor unit. This unit houses a compressor, a condenser coil, and a fan. Its main function is to compress the refrigerant, raising its temperature and pressure, effectively turning it into a hot, high-pressure gas.

The indoor unit contains an evaporator coil and a fan. When the hot, high-pressure refrigerant from the outdoor unit reaches the indoor unit, it passes through the evaporator coil. In this process, the evaporator coil absorbs heat from the indoor air, causing the refrigerant to evaporate into a low-pressure gas. This cools the indoor air. The cooled air is then circulated into the room by the indoor fan, providing air conditioning in the summer. Simultaneously, the heat absorbed from the indoor air is transported by the refrigerant back to the outdoor unit.

Mini-split heat pumps provide both heating and cooling. To switch to heating mode, a reversing valve within the system changes the direction of refrigerant flow. Now, the outdoor unit becomes the evaporator, and the indoor unit becomes the condenser. In this mode, the outdoor unit extracts heat from the outdoor air, even in cold weather, and releases it inside, providing efficient heating.

Compared to window units, mini-splits are generally more energy-efficient, offer better aesthetics, provide zoning capabilities, and have quieter operation. Window units are easier to install, but only cool or heat a single room and can be noisier, especially when placed in bedrooms.

Everything You Need To Know About Mini Splits

From Clean Air Heating & Cooling

Some Popular Models

1. Daikin Quaternity Series Heat Pump: Price Range: $3,000 - $8,000
   The Daikin Quaternity Series Heat Pump is a premium option that combines heating, cooling, dehumidification, and air purification capabilities. It utilizes advanced inverter technology to achieve high energy efficiency and precise temperature control. The Quaternity heat pump incorporates features like intelligent eye sensors that detect occupancy and adjust the operation accordingly, ensuring optimal comfort and efficiency. It also includes a built-in air purifier with a multi-stage filtration system to remove airborne contaminants. The Quaternity Series is designed for single-zone applications and offers quiet operation and user-friendly controls.
2. Carrier Infinity Series Heat Pump: Price Range: $3,500 - $9,000
   The Carrier Infinity Series Heat Pump is known for its premium performance and advanced features. It utilizes variable-speed technology to deliver exceptional comfort and energy efficiency. The Infinity heat pump includes features like Greenspeed intelligence, which adapts to changing conditions and modulates the operation to provide precise temperature control and enhanced energy savings. It offers superior humidity control, air purification, and quiet operation. The Infinity Series is available in single-zone and multi-zone configurations, allowing for customized comfort in different areas of the home. It also includes smart features like Wi-Fi connectivity for remote access and control.
3. LG Artcool Mirror Heat Pump: Price Range: $2,500 - $5,000
   The LG Artcool Mirror Heat Pump combines sleek design with advanced features. It offers both heating and cooling capabilities, providing year-round comfort. The Artcool Mirror heat pump features a stylish mirror panel design that blends seamlessly with any interior decor. It utilizes inverter technology to deliver efficient and quiet operation, adjusting the compressor speed to match the desired temperature. This heat pump includes features like Wi-Fi connectivity for remote control and monitoring through a smartphone app. It also incorporates advanced air purification technology, removing airborne particles and allergens to ensure clean and healthy indoor air.
4. Fujitsu Halcyon Series Heat Pump: Price Range: $2,500 - $6,000
   The Fujitsu Halcyon Series Heat Pump offers reliable performance and energy efficiency. It is available in various capacities to suit different room sizes and requirements. The Halcyon heat pump utilizes inverter technology, providing precise temperature control and reduced energy consumption. It features quiet operation and includes advanced filtration systems to improve indoor air quality. The Halcyon Series offers both cooling and heating modes, ensuring year-round comfort. It is designed for single-zone applications and offers convenient controls for easy operation. Fujitsu is known for its reliable and durable installers, making the Halcyon Series a popular choice for residential heating and cooling needs.

Four popular mini-split heat pump models:

1. Mitsubishi Electric M-Series: Price Range: $1,500 - $4,000 per indoor unit
   The Mitsubishi Electric M-Series is a well-known and highly regarded line of mini-split heat pumps. These systems are known for their energy efficiency and advanced features. The M-Series offers a wide range of indoor units to choose from, including wall-mounted units, ceiling cassettes, and concealed duct units. They feature inverter technology, allowing for precise temperature control and efficient operation. The M-Series also includes advanced filtration systems, providing improved indoor air quality. With options for single-zone or multi-zone configurations, the Mitsubishi Electric M-Series offers flexibility and comfort tailored to specific room requirements.
2. Daikin Aurora Series: Price Range: $1,500 - $3,500 per indoor unit
   The Daikin Aurora Series is a popular choice for mini-split heat pumps. These systems are designed for high energy efficiency and optimal comfort. The Aurora Series offers a range of indoor unit styles, including wall-mounted units, ceiling cassettes, and concealed duct units. They utilize inverter technology, ensuring precise temperature control and reduced energy consumption. The Aurora Series includes features such as intelligent sensors that detect occupancy and adjust the operation accordingly. These systems also offer advanced air purification and dehumidification functions, contributing to improved indoor air quality and comfort.
3. LG Art Cool Premier Series: Price Range: $1,500 - $4,000 per indoor unit
   The LG Art Cool Premier Series combines stylish design with advanced functionality. These mini-split heat pumps offer a range of indoor unit options, including wall-mounted units and ceiling cassettes. They feature inverter technology for efficient and precise temperature control. The Art Cool Premier Series includes smart features like Wi-Fi connectivity, allowing for remote control and monitoring through a smartphone app. These systems offer advanced air purification filters, helping to remove contaminants and allergens from the air. The Art Cool Premier Series is known for its sleek aesthetics, quiet operation, and customizable comfort.
4. MrCool: Price Range: $1,500 - $4,000 per indoor unit
   MrCool mini-split heat pump systems are energy-efficient, ductless solutions for both heating and cooling needs, known for their affordability and performance. They can be purchased at Home Depot and are DIY friendly.