Heat pump hydronic cooling

Example of an Galletti ART-U fan coil convector, which provides hydronic heating and effective cooling with chilled water below they dew point.
Galletti ART-U fan coil convector for hydronic heating and cooling

Galletti ART-U Fan Coil Convectors

Heat pump hydronic cooling and heating can be delivered efficiently with the stylish, wall mounted ART-U fan coil convector from Galletti.

This hydronic system is designed for cooling using chilled water from a reverse cycle heat pump in summer. An internal fan draws air through its coils.

Condensation is drained away outside, which gives you latent cooling as well as sensible temperature cooling.

In winter, hot water from the heat pump is circulated through the convector. The fan automatically slows or turns off as warm air naturally rises through its hydronic coils.

Jaga Briza Fan Coil Convectors

Mount fan coil convectors against walls, under ceilings, concealed in walls or concealed above ceilings.

Run ducting to provide cool air to several rooms from a concealed fan coil convector.

Design drop ceilings above robes and cupboards for concealed Jaga Briza fan coil convectors.

Image of Briza hydronic fan coil convectors, wall mounted, ceiling mounted, in-wall or in-ceiling types
Jaga Hydronic Fan Coil Convectors, Wall Mounted, Ceiling Mounted, In-wall or Above-ceiling Types
Hydrosol Image of Trench Hydronic Fan Coil Convector Installation
Trench Hydronic Fan Coil Convector installation, Heating and Cooling

Trench Convectors

Install trench fan coil convectors in your suspended floors. Fit them parallel to your structural floor joists. If you are renovating, make provision for the trench as part of your construction plans.

The Kitchen / Family area is the most important area of your house. It may have limited space for radiator panels if you have extensive glass windows and doors. Therefore, consider trench convectors beside your ceiling to floor windows.

Install trench convectors in your traffic areas such as glass doors because they are designed for foot traffic. Match the grilles to your flooring.

Add a chilled water circuit to run water below the dew point. Your trench convectors will absorb heat and moisture and therefore reduce the humidity build-up inside your house.

Create an efficient heating and cooling system with 1kW of power giving you up to 4kW of heating and cooling energy.

Space Saving Fan Coil Convectors

  • Space saving fan coil convectors can be mounted at floor level in cabinetry plinths or above robes and cupboards.

  • The internal fan draws air through cools with cool water running above the dew point in summer.

  • Install these convectors in areas that are difficult to reach with radiators, chilled water convectors, underfloor hydronic or air conditioning systems.
  • Choose from a range off facia panel colours to suit your décor.

Consider the dimensions + pipe clearances: 

  • 100h x 498w x 288d (0.7 to 1.3kW output, 60 deg)
  • 100h x 600w x 353d (1.5 to 1.7kW output, 60 deg)
Image of hydronic space saving fan coil convector for hydronic heating and cooling. Space saving fan coils are designed for tight spaces including cabinet plinths or above cupboards and robes.
Hydronic space saving fan coil convector designed for tight spaces including cabinet plinths.
Hydrosol image of underfloor hydronic circuits laid prior to the concrete screed layer with heat pump for heating and reverse cycle cooling.
Underfloor Hydronic Circuits

Hydronic Cooling Underfloor

Apart from heating, underfloor systems can provide area cooling also with hydronic water running above the dew point. However, they cannot absorb moisture.

Install the best and most efficient form of electric heating that also gives you effective cooling in summer. This works better in a dry climate.

Heat pump hydronic cooling systems rely on their large underfloor surface area to be effective. Use ceiling fans to improve their effectiveness.

More information: Case Study

Radiator Panels for Hydronic Cooling?

Can a heat pump be used for hydronic cooling using radiator panels?

Radiator panels are only marginally effective for cooling due to:

  • Low surface area for heat absorption
  • Cannot handle chilled water below the dew point

Add a fan coil convector circuit for effective hydronic cooling with chilled water.

Key Points:

  • Your heat pump is designed to run in reverse cycle so can provide some cooling at no added cost but the hydronic water must be above the dew point.
  • Radiator panels will be more effective for cooling when the temperature difference between the room air and the cool radiator is greatest, such as during heat waves.
  • Floor fans will help move air through cool radiator panels improving heat transfer via convection.
Hydrosol image of hydronic radiator panel
Hydronic Radiator Panel

Heat Transfer Rate

The rate of heat transfer for hydronic cooling in summer depends on the following:

  • Temperature difference between the water in your hydronic coils and the air in your room. For example, in a Melbourne summer, cool hydronic water may be 10-15 degrees lower than room temperature, whilst chilled water could be more than 20 degrees lower and hence more effective.
  • Surface area of the underfloor circuits. The greater the surface area, the greater the rate of heat transfer.
  • Rate of air flow across the surface area of the hydronic coils. Air movement increases the rate of heat transfer from convection.
  • Humidity. The drier the air, the easier it is for cooling.

Humidity & Cooling

  • Underfloor area cooling is effective with hydronic heat pumps in dry air. Heat pumps run cool water above the dew point through underfloor hydronic systems. Use this method in southern or inland Australian locations.
  • Fan coil convectors are better for humid air because they are designed to operate below the dew point with chilled water.  Therefore, they can dry out moist air and provide additional latent cooling.
  • Consider also a hydronic system that combines underfloor or panel radiator heating with fan coil convector cooling. Add an additional cooling circuit so your hydronic heat pump can be switched to fan coils with chilled water in summer.

Fans & Cooling

Turn on a fan and the perceived temperature will drop by around 4 degrees. This will make a room of 28 degrees feel comfortable immediately. Fans create air movement. Therefore, they are perfect partners for hydronic cooling systems. There are many suitable fans on the market including:

  • Ceiling fans (which will also assist your Star Rating)
  • Floor and desk portable fans
  • Air conditioning indoor units in air-only mode

Heat Pump Cooling

Unlike boilers, heat pumps provide both cooling and heating. They can produce either cool water for underfloor cooling or chilled water for convector cooling. 

Cool hydronic water is maintained above the dew point. Therefore, install fans to

  • Reduce the perceived temperature across your body by around 4 degrees
  • Improve air flow and the heat transfer rate across the cool surface area via convection

Thermal Mass

Construct your house with plenty of internal thermal mass if it is located in a southern or cold inland Australian climate. Create building mass with concrete floors, internal bricks, concrete walls and/or an over-sized buffer tank.

Run your heat pump or air conditioning systems during the day with your solar power for low-cost solar hydronic heating or cooling. The heating or cooling energy will be absorbed in your thermal mass. It is then released inside during the evening.

Consider enlarging your buffer tank if your home is constructed with a suspended floor. Water is a good store of thermal energy. Read more: Thermal Battery

Hydrosol Recommends

Hydrosol recommends the following steps to improve the effectiveness of radiator panel cooling:

  • Ensure your house is thermally efficient
  • Make sure you have summer shading with:
    • Appropriately designed eaves or slatted pergolas for northern windows
    • External awnings for western and eastern windows
    • Deciduous trees or vines shading northern, western and eastern windows
  • Use a fan to reduce the perceived temperature and improve cooling via convection.

Contact us to explore heat pump cooling for your project.