Water-to-Water Heat Pump Chillers for Hydronic Systems
Most chillers only cool. A water-to-water heat pump chiller does both — it can produce chilled water for cooling or hot water for heating from the same unit, by reversing the refrigeration cycle. That makes it a single piece of equipment covering both sides of a building’s thermal load. Jaideo Automation supplies units including the YVWH-200 water-to-water variable speed dual screw heat pump and the YMAE inverter scroll modular heat pump chiller.
The General Heat Pump Principle
Every heat pump, regardless of type, works by moving heat from one place to another using a refrigeration cycle that can run in either direction. A reversing valve is what makes that direction-switching possible — for hot water applications specifically, see the Heat Pump for Hot Water product, and for a large-scale option the CYK Water-to-Water Compound Centrifugal Chiller-Heat Pump. Water-to-water units — covered in detail below — are one of those types, exchanging heat between two water loops rather than with outdoor air.
Heat Pump vs Chiller: What’s the Real Difference?
A standard chiller is a one-way device — it only removes heat to produce chilled water, and has no mechanism to reverse that process. A heat pump chiller is a chiller with a reversing valve added, letting the same equipment also produce hot water on demand. Every heat pump chiller is technically still a chiller (it can run in cooling-only mode), but not every chiller can function as a heat pump. The practical question when choosing between them isn’t “heat pump or chiller” in the abstract — it’s whether the project needs heating capability from the same plant, in which case a heat pump chiller replaces what would otherwise be a separate chiller-plus-boiler setup. See our Chiller Selection Guide for where this fits in the broader decision.
How a Water-to-Water Heat Pump Chiller Works
A standard chiller only rejects heat outward. A heat pump chiller adds a reversing valve, so it can either:
- Cool: absorb heat from the building’s chilled water loop and reject it to a source loop (cooling tower, ground loop, or another water source)
- Heat: reverse the cycle, absorbing heat from the source loop and delivering hot water to the building’s heating loop
Because both sides of the cycle use water rather than air, these are “water-to-water” units — distinct from air-source heat pumps that exchange with outdoor air.
Why Use a Heat Pump Chiller Instead of Separate Systems
- One piece of equipment instead of a chiller plus a separate boiler
- Simultaneous heating and recovery is possible on some modular systems — heat rejected from a zone needing cooling can supply a zone needing heat
- Lower total mechanical room footprint
- Often better part-load efficiency with variable-speed / inverter-driven compressors, as in the YVWH-200 and YMAE ranges
Applications
- Hotels needing simultaneous cooling in guest rooms and heating for pools or domestic hot water
- Hospitals with mixed heating and cooling zones running year-round
- Mixed-use buildings with different load profiles on different floors
- Any hydronic system where the source loop (ground loop, condenser water, or another water source) is available
How This Fits Into Your Chiller Selection
A heat pump chiller is one branch of the broader chiller decision tree — see our Types of Chillers guide for how it compares to standard cooling-only chillers, and our Chiller Selection Guide for the full decision process.
Frequently Asked Questions
What is a water-to-water heat pump chiller?
A water-to-water heat pump chiller can produce either chilled water or hot water from the same unit by reversing the refrigeration cycle, exchanging heat between two water loops rather than with outdoor air.
When should a building use a heat pump chiller instead of a standard chiller?
When the building needs both heating and cooling capability, especially with simultaneous or seasonal demand for both, a heat pump chiller can replace a separate chiller-plus-boiler setup.
Can a water-to-water heat pump chiller provide simultaneous heating and cooling?
On modular systems like the YMAE series, yes — heat rejected from zones needing cooling can be redirected to supply zones needing heat, improving overall efficiency.