What is a monobloc heat pump?

Monobloc heat pumps are single unit heat pumps that contain all of the parts; like the heat exchanger, main pump, evaporator, condenser and compression valves in a single system. The single unit normally sits outside of your home.

Monobloc heat pumps are quite large and require outdoor space against an external wall so they can be installed correctly.

Monobloc heat pumps need professional installation but are simpler to install than air conditioning or ground or water source heat pumps.

The monobloc heat pumps outdoor unit will connect directly with your home’s conventional heating systems to provide heat through radiators or underfloor heating from external air.

Here’s What is a heat pump which explains the basics of heat pumps.

Pros and Cons of a Monobloc Heat Pump

The pros and cons of a monobloc heat pump system include;

Pros of Monobloc Heat Pumps

Some of the benefits of a monobloc heat pump system include;

  • Freeing up space inside your home – usually installed externally, monobloc systems don’t require internal exchangers or storage systems so can free up interior space inside your property.
  • Easy installation – because monobloc heat pumps are a single unit, containing the refrigerant and exchanger, they just need pipeworks to connect with your heating system.
  • Easy maintenance – a single system all self contained can be checked more quickly than a system with multiple parts inside and outside the property.
  • High efficiency and energy savings – because heat pumps extract heat energy from the air (or ground) you can make your home more energy efficient and spend less on heating and energy costs each month.

Cons of Monobloc Heat Pumps

Here are the disadvantages of monobloc heat pumps;

  • Lower overall heating capacity – compared to some types of heat pump monobloc heat pumps can have a lower heating capacity, making them less suitable for larger properties with many rooms.
  • Hot water storage is required – because monobloc heat pumps connect directly to your heating system, you won’t get hot water from your taps on demand. You will need a hot water tank to store hot water heated by the heat pump to feed hot taps in your property.
  • Not flexible – if your home gets larger after an extension or your heating needs change, you may need a new system. Monobloc heat pumps aren’t adaptable to heating increased space.
  • Outdoor space required – monobloc heat pump systems can be quite large. Properties without outdoor space won’t be able to have a monobloc heat pump installed. Properties with exterior space will require a ground floor exterior wall to have the monobloc system installed. These systems can also be very large because of the technology they contain.
  • Noise – monobloc heat pumps can be noisy when operating so if you’re heating your home overnight and you have a downstairs bedroom near where your monobloc heat pump is installed, your sleep may suffer. Here is how noisy heat pumps can be.
  • Cost – because of the technology the cost of monobloc heat pumps can be high. Check prices carefully and ensure you’re paying only for a monobloc heat pump you need for your property to try to keep costs down.
  • Very low temperatures can affect efficiency – if you’re considering a monobloc air source heat pump, then be aware that very low external temperatures can affect the output and efficiency of your heat pump. External pipes required to transfer heat inside your home will also mean heat energy is lost.

Do monobloc heat pumps produce hot water?

Monobloc heat pumps only heat water to pump around your central heating system which goes directly to your radiators or underfloor heating.

To get running hot water you will also need to install a separate hot water storage tank. The only element of a monobloc heat pump that will be located within your home is the connected hot water cylinder.

What is a Split heat pump?

Split heat pumps conversely are different to monobloc heat pumps because they have two separate units. The split system usually has an internal unit and an outdoor unit which works as a heat exchanger and compressor.

Split heat pumps are better for situations where more complex installations are necessary or when there’s no obvious place for a monobloc heat pump unit and they can also be very quiet.

They can be preferable if you only have a small outside space as the outside unit is generally smaller.

Split systems are often referred to as HVACs. Find out more about split HVAC heat pump systems.

What is a Monobloc Air Source Heat Pump?

Monobloc air source heat pumps include all of their essential parts and equipment within a single unit that can be installed outside your home.

The majority of monobloc air source heat pumps, don’t require traditional gas to work instead they use refrigerants so monobloc heat pumps do not require F gas qualifications (fluorinated gas) to install.

This makes many monobloc heat pump systems cheaper and easier to install than air conditioning units or ventilation systems.

Most monobloc heat pump systems will need to be installed by professional heating installers.

Where can a Monobloc Heat Pump Unit be Situated?

Air source monobloc heat pumps will need external air so the majority of systems are designed as a single outdoor unit that is installed outside the property.

The external unit will need to be installed at ground floor level and somewhere that is easy to access for ongoing maintenance and servicing.

Many people choose to have their heat pump unit situated outside their utility or boiler room is a popular choice because it is easy to connect the heat pump to the heating system.

The outside unit is generally reasonably large due to housing all of the components necessary to get your home’s heating up and running.

Monobloc heat pumps can work well on large properties where you have plenty of outdoor space to house the system and let it operate successfully.

Can you get Monobloc Ground Source Heat Pumps?

You can get monobloc ground source heat pumps and water source heat pumps. However, they will need to connect to a suitable heat source, through boreholes, aquifers, lakes, rivers or waste heat through a series of pipes.

A monobloc ground source heat pump can still be considered a split system because ground and water source systems require underground or underwater pumps in boreholes to access heat from the ground or a body of water to generate heat.

You will also need an internal hot water tank to store hot water from your heat pump to feed hot water taps in your home.

Monobloc Heat Pump FAQs

Can a Monoblock heat pump be installed in cold climates?

Most monobloc heat pumps can work effectively in temperatures as low as -25° C. Many heat pumps designed for lower temperatures feature enhanced vapour injection (EVI) technology that helps to maintain the pressures of the refrigerant even at low temperatures.

In a much colder climate, a ground source monobloc heat pump could be a better option as ground temperatures are more stable throughout the year than air temperatures.

Air sealing and insulation, as well as correctly sizing the heat pump for your home are also important considerations.

How to make your home ready for a heat pump?

If you’re replacing a traditional boiler with a heat pump, you shouldn’t have too many changes to make. However, you may wish to;

Improve your home’s insulation; this will help your home retain more heat so your heat pump won’t have to work so hard to keep your home at a comfortable temperature. Many UK homes are currently poorly insulated.

Upgrade your radiators; heat pumps work best when they have a larger surface area to distribute heat. So upgrading your radiators can help your home feel warmer more quickly. Replacing existing radiators with aluminium radiators can also help distribute heat from your heat pump quickly and efficiently as aluminium is an effective conductor.