Heat pump systems are well-known for heating and cooling homes and buildings in New Zealand due to their efficiency and environmentally friendly operation. These systems transfer heat from one place to another, providing both heating and cooling in a single unit. However, the efficiency and effectiveness of a heat pump system heavily depend on its installation. An incorrectly-installed heat pump can lead to numerous problems, including reduced efficiency, increased energy bills, and frequent breakdowns. Through servicing thousands of heat pumps over many years, we have come across numerous installations that have not been done correctly. This article explores the potential issues that can arise while installing a heat pump system and offers guidance on how to avoid these pitfalls.
Top 10 Common Heat Pump Installation Mistakes
Incorrect Sizing: One of the most common mistakes during heat pump installation is incorrect sizing. A heat pump must be correctly sized to match the heating and cooling load of the home or building. In addition to the basic size calculations, not factoring in a home’s insulation and solar gain levels can also cause significant problems. Heat pumps rely on the proper insulation of the home or building to function efficiently. If the property is not well-insulated or if there are gaps and leaks in the building envelope, the heat pump will have to work harder to maintain the desired temperature. This can lead to increased energy consumption and higher utility bills. An undersized unit will struggle to reach the desired temperature, leading to increased wear and tear, higher energy bills, and reduced comfort. On the other hand, an oversized unit will cycle on and off frequently, leading to inefficient operation and a shortened equipment lifespan.
Positioning: Another common installation mistake is poor placement of both indoor and outdoor units. The outdoor unit should be placed in a location that allows for adequate airflow (at least 150mm from the wall behind) and is free from obstructions such as plants or debris (at least 500m in front). If the unit is installed too close to walls or other structures, it can restrict airflow and reduce the system's efficiency, not to mention causing additional noise to nearby neighbours. If you live in a sea spray or sulphur zone, special coating is advisable and may even be required by the manufacturer for warranty coverage purposes. Similarly, the indoor unit should be strategically placed to ensure optimal air distribution throughout the room. Incorrect placement can lead to uneven heating or cooling and reduced comfort levels. It should also never be installed in a kitchen as cooking oils in the air can significantly impact a heat pump’s performance and lifespan.
Poor Wiring: Poor wiring quality is another common problem during heat pump installation. Improper wiring and electrical connections can pose serious safety hazards, including the risk of electrical fires. It is essential to ensure that a licensed electrician performs all electrical work and that it complies with local codes and regulations. The heat pump should also be connected to a dedicated circuit to prevent overloading the electrical system and the correct size wiring must be used. This is especially important for large heat pumps and those with long wiring runs where 4mm or even 6mm cable may be required.
Refrigerant Issues: Another critical issue is an incorrect refrigerant charge. The charge must be precisely calibrated to match the heat pump’s requirements. An incorrect charge can lead to reduced efficiency, higher energy bills, and potential damage to the system. Too much refrigerant can cause high pressure in the system, while too little can result in insufficient cooling or heating as well as damage the compressor - the single most expensive part in a heat pump.. A common mistake made by installers is not to add additional refrigerant gas charge when the pipe run is 10m or more. Both scenarios can lead to a heat pump breakdown and costly repairs.
Poor Ductwork Design: Ductwork design and installation play a crucial role in the performance of a ducted heat pump system. Poorly designed ductwork can lead to increased pressure, inadequate airflow and reduced efficiency. For example, extended duct runs, sharp bends, and excessive branching can all create resistance to airflow, making it harder for the heat pump to distribute air throughout the property. This can result in uneven heating or cooling and increased energy consumption. Leaks and inadequate sealing in the ductwork are also common issues. Leaky ducts can lose up to 30% of the heated or cooled air before it reaches the intended areas of the home or building. This not only reduces the system's efficiency but also increases energy bills. Ensuring that all duct connections are properly sealed can significantly improve the heat pump's performance. Incorrect duct sizing is another problem that can affect a heat pump's performance. If the ducts are too small, they can restrict airflow and cause the system to work harder than necessary. Conversely, if the ducts are too large, the air velocity can be too low, leading to poor air distribution and reduced comfort. Lastly, installers must ensure there is sufficient return air, This again requires accurate calculations regarding the size of the return ducting as well as the return grille(s).
Drainage and Ventilation Issues: There should be enough gravity fall to ensure prompt drainage of water from the indoor unit outside. Proper condensate drainage is essential for efficiently operating a heat pump system. If the condensate drain is not correctly installed, it can lead to water damage and mould growth. The drain should be sloped correctly to ensure water flows away from the unit and is disposed of properly. Regular drain maintenance and cleaning can also help prevent clogs and sludge buildups. Insufficient ventilation can also impact a heat pump's performance. Proper ventilation is necessary to maintain good indoor air quality and ensure the heat pump operates efficiently. If the home or building is not adequately ventilated, it can lead to a buildup of pollutants and moisture, which can affect the health of the occupants and the heat pump's longevity.
Operational and Performance Problems: Incorrect wall controller/thermostat placement and settings can significantly affect the performance of a heat pump system. The thermostat should be placed in a location that accurately reflects the average temperature of the home or building. Placing the thermostat near heat or cold sources, such as windows or doors, or hot ones, such as a wall that is exposed to strong sunlight, can lead to inaccurate readings and inefficient operation. Additionally, the thermostat settings should be properly configured to ensure the heat pump operates efficiently and maintains the desired temperature. Avoid setting temperatures to extremes like 16 degrees cooling or 27 degrees heating - your system will struggle to reach those temperatures, but will use a lot of electricity trying to do so. Ignoring manufacturer specifications and guidelines during installation can lead to numerous problems. Each heat pump system is designed to operate within specific parameters, and failing to follow the manufacturer’s instructions can reduce efficiency and damage the system. Adhering to all installation guidelines and using the recommended components and materials is crucial.
Poor Quality Installation Materials: Like most products, there are some that are high quality and durable, but many more that are poor quality and should not be used. Look for materials sourced from reputable electrical or specialist HVAC companies. Make sure that your installer knows to use only stainless steel screws for anything outside. Check that silicone is used where necessary but sparingly, and that the installers pick up and remove, tidy up all electrical wiring offcuts etc.
Not Properly Evacuating the Pipework: Before the system is turned on for the first time, the install technicians must always first evacuate the pipeset with a special vacuum pump to remove any air and moisture which could cause premature failure in your heat pump system. A digital gauge should be used and the process should not be finished until the gauge is showing 200 microns or less.
No Proper Commissioning Process Undertaken: A thorough check should be conducted after installation (called “commissioning”) to ensure that all components function correctly and that the system operates within the specified parameters. This includes checking the refrigerant charge, electrical connections, airflow, and overall system performance.
Long-term Consequences of Poor Installation
The long-term consequences of poor heat pump installation can be significant. One of the most immediate impacts is increased energy bills. An improperly installed heat pump will not operate efficiently, leading to higher energy consumption and increased power bills of up to 30% compared to what a properly-installed and maintained system. Over time, these higher bills can add up, making the heat pump system more expensive to operate than necessary.
A poorly installed heat pump is also likely to have a reduced lifespan. The additional strain on the system caused by incorrect sizing, poor placement, or other issues can lead to premature wear and tear. This can result in more frequent breakdowns and the need for costly repairs or even replacement of the entire system sooner than expected.
How to Ensure Proper Installation
To avoid the issues associated with poor heat pump installation, hiring qualified and experienced professionals is essential. There are no qualifications in NZ required as such, however only qualified installers will have the knowledge and expertise to ensure that the heat pump is correctly sized, placed, and installed according to manufacturer guidelines and local codes. Checking references and reviews can help identify reputable contractors. Ask them if they have attended manufacturer training sessions and when their last training session was. Heat Pump technology and regulations are constantly changing, and it is important for technicians to stay up to date.
Following manufacturer guidelines is crucial for the proper installation and operation of a heat pump system. These guidelines are designed to ensure that the system operates efficiently and reliably. Adhering to the recommended procedures and using the specified components can help avoid many of the common installation issues.
Regular maintenance and check-ups are also essential to ensure the long-term performance of a heat pump system. Routine inspections and servicing can help identify and address potential problems before they become serious issues. This includes checking the refrigerant charge, cleaning the coils, inspecting the ductwork, and ensuring that all electrical connections are secure.
Below is a simple checklist to ensure a proper heat pump installation:
Ready For Your Heat Pump Installation?
Proper heat pump system installation is critical to its efficiency, performance, and longevity. Common installation mistakes, such as incorrect sizing, poor placement, and inadequate insulation, can lead to numerous problems, including increased energy bills, reduced system lifespan, and frequent maintenance issues. Ensuring that the installation is performed by certified and experienced professionals, following manufacturer guidelines, and conducting regular maintenance can help avoid these pitfalls and ensure that the heat pump system operates efficiently and reliably. By taking these steps, New Zealand homeowners and property developers can enjoy the benefits of an effective and efficient heat pump system.