Application of EVI (Enhanced Vapor Injection) heat pumps

EVI (Enhanced Vapor Injection) heat pumps are advanced air source heat pump systems designed to deliver superior performance in extremely cold climates and high-temperature applications. 

Principle of Ultra-low Temperature Air Source Heat Pump

The ultra-low temperature air source heat pump unit consists of four main components: evaporator, condenser, compressor and expansion valve, forming a closed system and filled with an appropriate amount of working fluid. The basic principle of the operation of the ultra-low temperature air source heat pump is the reverse Carnot cycle. The liquid working fluid first absorbs heat from the air in the evaporator, and then evaporates to form steam (gasification). The latent heat of vaporization is the recovered heat, which is compressed into a high-temperature and high-pressure gas by the compressor and condensed into a liquid (liquefaction) in the condenser. The absorbed heat is transported to the necessary heating pool, and the liquid working fluid is decompressed and expanded through the expansion valve, and then returns to the expansion valve to absorb heat and evaporate. Compared with ordinary heat pumps at -10°C and lower temperatures, the evaporation temperature is too low, resulting in less evaporation, resulting in less compressor backflow, which affects condensation heat dissipation. The ultra-low temperature air source heat pump unit is also equipped with an injection enthalpy increase branch connected to the compressor.

When the return air of the compressor is insufficient, the injection enthalpy increase branch will supplement air to the compressor, so the heat release of the condenser will increase, so it can still be heated normally at very low temperatures

Applications of EVI Heat Pumps

1. Residential Heating in Cold Climates

EVI technology allows heat pumps to operate efficiently at –35°C or lower.

Ideal for:

Northern Europe, Canada, Northern China, Alpine regions.

Radiator or underfloor heating in houses or apartments.

Maintains stable heating and domestic hot water (DHW) supply even during harsh winters.

2. Commercial and Public Buildings

Suitable for schools, hotels, hospitals, and office buildings needing:

3. Industrial Heating and Hot Water

EVI heat pumps can support industrial processes requiring higher temperatures (e.g., up to 80–85°C).

Used in:

Food processing (cleaning, pasteurization).

Textile and pharmaceutical factories.

Chemical washing or drying systems.

4. Swimming Pool Heating in Cold Regions

Maintains comfortable pool temperatures even during winter seasons.

Efficient for indoor pools, public aquatic centers, and high-altitude hotels/resorts.

5. District Heating and Multi-Family Housing

Supports centralized heating and hot water supply across:

Apartment buildings

Villas and housing estates

District energy networks in suburban or rural communities

6. Boiler Replacement or Hybrid Systems

Replaces traditional gas or oil boilers, especially where carbon reduction or clean energy mandates apply.

Can be integrated into hybrid systems with solar or biomass.

Leomon Heat pump can offer up to 150 ℃ hot water,heat pump and cassede heat pump, refrigeration such as R134a, R1234ze, R245fa, or natural refrigerants like CO₂ (R744) or hydrocarbons (R600a).

Brand: offer own brand or customized authorized brand.