Engineering and modern style are the signatures of this innovative, high-temperature air-to-water heat pump.

A fcompressor developed by Japan’s Daikin Technology and Innovation Center and Daikin Europe can deliver high-leaving water temperatures as high as 158°F (70°C). It utilizes low-GWP R-32 refrigerant that releases fewer CO2 emissions than R-410A. 

One Solution, Multiple Possibilities

“With its versatility, quiet operation, space-saving design and modern esthetic, Daikin ALTHERMA 3 H HT combines form and function to solve indoor comfort challenges effectively in both retrofit and new construction, especially in areas with low ambient temperatures,” said Edwin Reek, director water heating solutions for Daikin. 

Flexible system combinations can allow for easy integration for boiler, gas furnace and optional gas domestic hot water replacement. Once the Daikin ALTHERMA 3 H HT outdoor unit is connected to the indoor unit (hydro box), the system can connect to emitters already in the home, like baseboards or radiators, integrate with Daikin’s heat pump convectors, or pair with hydronic air handlers and in-floor radiant loops. 

Engineered for extreme climate applications, the Daikin ALTHERMA 3 H HT can operate down to -18°F (-28°C) while still delivering space heating and optional domestic hot water. It can provide cooling even when outdoor temperatures reach 109°F (43°C). 

Operating as quietly as a low-library murmur, down to 41 dBA, the Daikin ALTHERMA 3 H HT is engineered for tranquility. A LOW sound mode setting silences sound pressures further, down to 35 dBA. 

“The outdoor unit incorporates an advanced, hidden fan shaped to minimize the air contact surface, helping maintain a low sound level,” Reek said. “To absorb and insulate the sounds made during compressor operation, three layers of insulation surround the compressor, while double sound reduction plates are used between the bottom plate and vibration plate.”

While most high-capacity HVAC units operate with two fans, Daikin ALTHERMA 3 H HT outdoor units need only one. A large fan enhances air circulation and helps lower operational noise.

Though quiet and compact, the heat pumps deliver strong energy efficiencies by leveraging Daikin’s proven inverter technology and R-32’s thermodynamic properties. Inverter-driven compressors and fan motors — plus micro-processor controls — are designed to deliver constant comfort and high-efficiency performance.

 “Replacing fossil fuel boilers and furnaces with an advanced, modern hydronic heat pump like the Daikin ALTHERMA 3 H HT contributes to sustainability.” said Reek.

Air-to-Water Difference: Heating, Cooling, & Optional Hot Water

Homeowners are becoming more familiar with heat pump systems to heat and cool their homes, using outside air along with the heat pump refrigeration system to create warm or cold air for their homes. Commonly understood hydronic boiler systems heat water by burning fossil fuel (natural gas, propane or oil), using that water to warm a home through base boards, radiators or underfloor heating. They can also supply domestic hot water.  

Unlike boiler systems that burn fossil fuels, Daikin ALTHERMA 3 H HT is an all-electric air-to-water heat pump that can provide home heating and optional domestic hot water without burning fossil fuels directly by the system — and can also deliver cooling. Daikin ALTHERMA 3 H HT air-to-water heat pumps extract heat energy from the outside air and transfer it to water for space heating and optional domestic hot water. But ALTHERMA 3 H HT’s air-to-water heat pump technology can also reverse its cycle, chilling water to cool a home. The chilled water circulates through fan coil units, gently lowering indoor temperatures for consistent, comfortable cooling. This gives the Daikin ALTHERMA 3 H HT flexibility to deliver sustainable indoor heating and cooling comfort in both ducted and ductless homes. 

Ultimately, said Reek, Daikin ALTHERMA 3 H HT high-temperature, air-to-water, electric heat pumps leverage innovation and style into an efficient, sustainable indoor comfort solution, supporting the transition away from fossil fuel-based systems toward all-electric systems.