Warm pool water outside the summer season, heating for a guest house and hot water for a small hotel may sound like similar requirements. They can need different equipment. China manufactures heat pumps for each application; selection should start with the site and operating conditions, rather than an inverter label or a large advertised output figure.
How a heat pump works
A resistance heater converts electrical energy into heat. A heat pump transfers heat from its surroundings. An air-source model takes heat from outdoor air and supplies it to water or indoor air. Electricity powers the compressor, fan and auxiliary components.
COP expresses the relationship between heat output and electrical input. As an illustrative example, a COP of 4 means that 1 kWh of electricity corresponds to 4 kWh of transferred heat. This is an example, not a specification for every machine. Actual COP changes with air temperature, required water temperature and operating load. Circulation and auxiliary equipment must also be considered.
What the inverter changes
Inverter control varies compressor speed and output. When less heat is needed, a suitable system can reduce its load instead of repeatedly running at full output and stopping. Full Inverter configurations may also regulate fan speed; confirm the exact arrangement for the model being quoted.
Compare output ranges, electrical input and sound levels at equivalent test conditions. An advertised percentage saving does not establish the future electricity use of your particular installation.
Can it operate below freezing?
0°C is not a universal cut-off. Fairland specifies an outdoor operating range of −15 to +43°C for the X17 Vertical. Other series differ: PHNIX states operation down to −20°C for its specific i-GreenLine Ultra range. These figures apply to the named equipment, not to every heat pump manufactured in China.
Being able to operate below freezing does not mean maintaining the same output and COP. Cold-weather selection must account for delivered heat, defrost operation and protection of the water circuit. Ask for capacity and input tables at the temperatures that matter for the actual site.
For an outdoor pool in winter, a minimum operating temperature alone is insufficient. Available output must be compared with surface, evaporation and wind-related heat losses. Year-round operation needs its own calculation.
Applications require different equipment
Pools and leisure facilities
Pool heat pumps are selected using water volume, surface area, target temperature, operating season and pool-cover use. Check heat-exchanger compatibility with the water treatment system, including salt chlorination where applicable. A pool cover helps reduce heat losses and changes the assumptions used for sizing.
Homes, hotels and commercial buildings
Underfloor heating, radiators, fan coils and domestic hot water require equipment intended for those duties. Check supply-water temperature and output at the design outdoor temperature. A pool model is not automatically a boiler replacement: operating temperatures, hydraulic circuits and controls can differ.
Information to send for selection
- City, installation location and intended operating season.
- For pools: dimensions, depth, cover use and target water temperature.
- For buildings: use, floor area, insulation and the existing heating system.
- Available electrical supply, outdoor-unit space and sound constraints.
- Whether the task is temperature maintenance or rapid heating after downtime.
Before purchasing from China
A comparable quotation should identify the exact model, performance tables, electrical requirements, included components and documentation. Confirm the controller, circulation pump, hydraulic accessories, spare parts and warranty process separately. Agree the connection design and freeze protection with the installation contractor.
Compare several options against the same brief. Separate equipment, sourcing services, freight and installation costs: a low unit price does not establish the lowest complete-system cost.
Technical references
Fairland X17 Vertical: operating range · PHNIX i-GreenLine Ultra: cold-weather series · YourHome: pool heating and heat losses
Minimum goods order: USD 2,000. Services and shipping are calculated separately.