Hydronic Heat Pumps

Hydrosol image of Stiebel Eltron 14kW model WPL25ACS hydronic heat pump installation
Stiebel Eltron 14 kW Model WPL25ACS Hydronic Heat Pump
Schematic showing an underfloor hydronic heating and cooling system with a heat pump.
Underfloor Hydronic Heating and Cooling System with a heat pump

Hydronic Heating

Hydronic heat pumps that use the outside air as the heat source produce air-to-water heating and cooling. Reverse cycle air conditioners produce air-to-air heating and cooling. Hydronic heat pumps can also extract heat from the ground, water or effluent. However, these options are more expensive but can make sense in alpine areas or commercial facilities.

Heat Pumps

The main advantage of air-to-water heat pumps is the ability to transfer heat through water lines using both radiation and convection.

Heat from circulating hot water can be radiated from your floor, radiator panels or towel rails.  Also, there are some hydronic fan-coil convectors that are designed for both heat convection and radiation. Heat radiated at floor level will rise naturally. This provides gentle even heat throughout your house.

Consider hydronic heat pumps if you suffer from allergies or asthma. You will value radiant heat more.

Another advantage of hydronic heat pumps is the use of water lines to transfer heat. This makes life much easier for architectural design. It is also more environmentally friendly than running refrigeration lines or air ducting for reverse cycle air conditioners.

Air Conditioners

The main advantage of air-to-air conditioners is that they are less expensive but can only transfer heat using convection.

This is perfect for cooling, where feeling the airflow is beneficial and reduces the perceived temperature. However for heating, radiating heat is the gold standard.

For two storey houses in particular, a combination of hydronic heat pumps on the ground floor and reverse cycle air conditioners on the first floor can make good sense for both comfort and economy. 

Hydronic Cooling

Hydronic heat pumps can heat and cool, whereas gas boilers can only heat. Consider changing over your gas boiler to an electric heat pump. There are a number of advantages. Click here for information on this.

Hydronic heat pumps provide cooling through either fan-coil convectors or underfloor circuits cooling your floor surface temperature. The former is more effective because convectors are designed to take chilled water below the dew point. Underfloor area cooling, on the other hand, is designed for cool water above the dew point.

Chilled Water Cooling

Chilled water employs sensible cooling (temperature) and latent cooling (dehumidification) which makes it mor effective. It is also helped due to the greater temperature difference (Delta T) between the chilled circulating water and inside temperature. Click here for convector pricing

Cool Water Cooling

However, if you have invested in an underfloor heating system, you have the option of using cool water from the heat pump working in reverse cycle to circulate cool water underneath your floor. The objective is to keep your floor surface temperature at around 18 degrees. This feels nice on your bare feet in summer.

Thermally Efficient House

If you plan to use underfloor area cooling, it is important to  have a thermally efficient house.

The key considerations are:

  • Good insulation
  • Good summer shading
  • Air tight house

Ceiling fans

Ceiling fans should also be used for underfloor area cooling. This lowers the perceived temperature across your body and helps your cool floor absorb more heat.

Cinier Greenor convector cooling visualisation
Hydrosol image showing hydronic underfloor heating circuits laid prior to the concrete pour.
Image of Immergas Magis heat pump
Immergas Magis heat pump, model range from 6 to 30kW

Which Hydronic Heat Pump is Best Suited?

Contact us to explore which heat pump is best suited to your project. They all have different characteristics.

Hydrosol will also consider the thermal performance of your house, your preferences, installation options and your budget in order to find the best match for you.

Hydrosol recommends these hydronic heat pumps:

All of these heat pumps are well supported in Australia, with excellent reputations and warranties: heat pump pricing.

Power your Hydronic Heat Pumps with Solar

Use your solar power to operate your hydronic heat pumps during the day. Energize the thermal mass inside your house during the day then release it at night.

Install batteries for chemical storage of solar power. Alternately, make a plan to install batteries when they become more cost effective. Consider oversizing your buffer tank to use as a thermal battery. Incorporate this into your solar power plan.

Design for an all-electric house to future proof against fossil fuel price rises. Play your part to help reduce greenhouse gas emissions.

Image of off-grid solar panel installation maximizing roof space and orientation
Solar panel installation maximizing roof space and orientation

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