Heat pump installation: overview & considerations

Thursday, 23rd September 2021

Heat pumps are used across commercial, industrial and residential settings for heating and cooling. When used in the right environment they save energy and money and drastically reduce greenhouse gas emissions. 

In addition to the environmental and financial savings, heat pump installation also equates to flexible running options, with many products being able to switch between heating and cooling. Highly durable products, they have an average lifespan of around 15 years and often a lot longer. 

While heat pumps offer a myriad of benefits, there are a number of design and project site considerations that need to be taken into account when it comes to product selection and heat pump installation. 

This article covers:

  • Heat pumps: a brief introduction
  • Types of heat pump / chiller
  • Where are ‘air to water’ heat pumps used?
  • How does an air to water heat pump work?
  • Design and site considerations
  • Choosing the right hydronic heating and cooling solutions 

Heat pumps: a brief introduction

A heat pump is a device used to heat and cool residential, industrial and commercial spaces, by transferring thermal energy from the surrounding environment outside of the building, into the system, which extracts the heat absorbed from outside and uses it to heat the space within the building. 

When it comes to cooling, the chiller operates in the opposite, removing heat from the indoor space and pushing the heat absorbed from inside back out into the environment. 

There are a number of heat pumps, each using a different energy source, including:

  • air source
  • geothermal (ground-source)
  • solar assisted
  • water source
  • exhaust air
  • hybrid heat. 

Types of heat pump / chiller

The breakdown below outlines the two main heat pump options used in commercial settings worldwide. 

At Hunt Heating Commercial, we focus on air to water heat pumps and chillers as they offer flexible power options, less overall infrastructure requirements and are more suitable for the Australian climate that we service. 

 

Air to water

  • Heat pump or chiller
  • Available from 6kw-1000kw+
  • Used for space heating/cooling & industrial applications
  • Common in Australia
  • Minimal infrastructure required
  • Performance dependent on Ambient Temperature
  • Operating limitations
  • Customisation / build options

 

 

Water to water 

  • Heat pump or chiller
  • Available 5kw-750kw
  • Used for space heating/cooling & industrial applications
  • 2-pipe or 4-pipe
  • Less common in Australia
  • More commonly used in colder climates
  • Increased infrastructure: bore / excavation & pipework
  • Performance dependent on water source temperature
  • Operating limitations
  • Build options 

 

Where are ‘air to water’ heat pumps used?

Air to Water heat pumps and chillers are used to heat and cool a wide range of commercial premises and settings, often within a hydronic system. 

Common hydronic heating and cooling applications include:

  • Schools (radiator panels and underfloor heating)
  • Hotels (fan coil & air handling units)
  • Supermarkets (air handling units)
  • Swimming pools (pool and building)
  • Office buildings (air handling & fan coil units)
  • Multi-residential buildings (panels, fan coil & air handling units, domestic hot water)
  • Hospitals (panels, fan coil & air handling units). 

How does an ‘air to water’ heat pump work?

  • Air from outside of the building is drawn in via the heat pump and pushed over a system of pipes, which are filled with refrigerant.
  • The ambient temperature warms the refrigerant, turning it from a liquid into a gas.
  • The gas then passes through a compressor, which in turn increases the gas pressure.
  • Heat is generated as the gas pressure increases.
  • The compressed, hot refrigerant gas then passes through a plate-to-plate heat exchanger, which is where hydronic system water is also being pumped.
  • The heat exchanger enables the heat from the gas to be transferred to the cooler hydronic system water.
  • Once the heat transfer has taken place and warmed the water, the pressure and temperature of the refrigerant begins to decrease and condense.
  • An expansion valve reduces the pressure of the refrigerant completely, causing it to return to its original liquid state. 

Design and site considerations for heat pumps

When it comes to planning the heating and cooling for your commercial project, it is vital that the correct hydronic heat pump products are selected, which can be done by assessing the specific design and site conditions of your project. 

At Hunt Commercial, we combine our experience in working across a diverse range of commercial projects, with specialist selection software from manufacturers to carefully and accurately select and recommend the best products for your needs. 

The primary design and site considerations include:

  • Ambient air temperature
  • Heating / cooling capacity requirements
  • Power availability
  • Physical space on site 

1.      Ambient air temperature

The temperature of the ambient air is the fuel source of any air to water heat pump. When ambient air temperature changes, so does the performance of the heat pump. 

We would assess the minimum ambient air temperature for the region where your project is located to select the most appropriate heat pump product. For example, a ski lodge installation will likely require a different product in comparison to an Australian urban office building given the difference in general temperature. 

2.      Heating / cooling capacity requirements

Whether you are after a heat pump that also doubles as a chiller, or your project only requires heating or cooling as a stand-alone, will be a key consideration when it comes to product selection. In addition to this, the temperatures that you want your heat pump to be able to warm and/or cool to will need to be taken into account. 

·         2-pipe or 4-pipe model

Some heat pump manufacturers offer solutions with a special function known as ‘total heat recovery’, often referred to as 4-pipe heat pumps. These products are a single unit which carries both a heat pump and chiller and can operate simultaneously or concurrently. The efficiency of this product is increased when it is running heating and cooling systems concurrently. Typically, with this set up, one side of the system can both heat and cool and the other side will heat only. With a 2-pipe model, one pipe is for the supply of the heat or cooling and the other pipe is for the return and can only perform either heating or cooling at any given time. 

3.      Power availability on site

Heat pumps and chillers have different power requirements. The power availability on your project site will dictate which products are available to you, in addition to the other design and site conditions. 

4.      Physical space on site

Another important site consideration is the availability of space at your project site. Firstly, there’s the space required to fit the heat pump and buffer tank, taking into account the floor space, but also the height of the units. 

The buffer tank holds a volume of water (volume depending on the product requirement) that is needed for the heat pump or chiller to operate efficiently. 

The efficiency of the heat pump/chiller will be impacted by the set up and it is vital that the product has ample space not only for the installation, but also adequate clearance around it for optimum operation. 

heat pump hydronic heating, heat pump installation

Choosing the right hydronic heating and cooling solutions

In addition to these four key considerations when installing a heat pump, other design and site considerations include:

  • Retrofit vs. new installation
  • Structural soundness
  • Total system capacity
  • Noise
  • Transportation
  • Cost
  • Flow rates
  • Buffer tanks 

All of these considerations, measurements and requirements are taken into account during our specialist services such as our hydronic heating and cooling design consultation and assessment. We will be able to ensure your project is setup for success from the start so you can meet your project requirements and budget, as well as ensure you and your clients get the most from your heat pump set up. 

We will be able to help you identify which combination of products are most appropriate for your project needs, from a complete end to end product offering across:

  • Heat pumps
  • Condensing water heaters
  • Terminal products
  • Hydronic heating and cooling
  • Underfloor heating
  • Expansion systems
  • Separators and filtration
  • Pumps
  • Domestic hot water storage
  • Accessories 

Commercial heating and cooling experts

The team at Hunt Commercial are backed by over 30 years of experience in hydronic heating for domestic and commercial projects.  Whether you’re working on a commercial office space, retail complex or tourism project – we have proven expertise working across a diverse range of projects including:

  • Elks at Falls (VIC) – ski lodge
  • Bannister Downs Dairy (WA) – Agriculture
  • Martin Place (NSW) – Office building
  • Spire Apartments (ACT) – Multi-residential
  • Stokehouse (VIC) – Hospitality
  • North Queensland Stadium (QLD) – sports & leisure
  • Coles Flagship (VIC) – Retail
  • The Star Casino (QLD) - Hotel  

Contact the Hunt Commercial team to discuss your options for hydronic heating and cooling solution for your next commercial projects to tap into our decades of experience and the most comprehensive range of commercial hydronic heating products in Australia.

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