Heating an orangery

Heating an orangery Heating an orangery 

Heating an orangery

The three most popular methods of heating an orangery are:

  • Radiators
  • Wet underfloor heating
  • Electric underfloor heating

It is important to consider carefully the merits of each system before deciding which will be the best option for your orangery.


Heating an orangery with radiators

Extending the central heating system out into an orangery is usually less expensive to install than underfloor heating.  However, orangeries have limited wall space so it may be difficult to site large enough radiators to provide the heat output needed.

Plus points of heating an orangery with radiators:

  • Lower cost to install
  • Quick response time
  • Add Thermostatic Radiator Values (TRVs) for independent control
  • Large choice of radiator designs

Minus points of heating an orangery with radiators:

  • Radiators take up significant wall space
  • Limit wall space for furniture
  • May overload existing central heating boiler
  • Pipe runs may need to be through existing rooms

Radiators despite their name, operate primarily as convectors.  In an orangery the warm air will rise up and collect in the lantern space rather than circulate, accentuating the hot head, cold feet effect of convecting systems.

If you are planning to finish the orangery floor with stone or ceramic tiles, remember these will stay cold if the room is heated by radiators.

If the orangery is to be used as an open plan living space with a kitchen, don’t forget that it may be an option to have kick space heaters.  These fit into the void behind the plinth of kitchen units and have a heater matrix linked to the central heating system.  A gentle, almost silent electric fan sends the heat out into the room.


Heating an orangery with underfloor heating

There are three types of underfloor heating:

  • Wet underfloor heating
  • Electric underfloor heating (in-screed cable)
  • Electric underfloor heating (heat mat)


Wet underfloor heating for orangeries (in-screed)

Wet underfloor heating (in-screed)

This is perhaps the ultimate solution for heating an orangery, but has a higher installation cost than electric underfloor heating.

Plus points of wet underfloor heating:

  • Warm feet/cool head effect for the most comfortable heating effect
  • Hidden system, so no loss of wall space
  • Ideal for ceramic or stone floors (toasty warm feet)
  • Very efficient method of heating.  Underfloor heating adds only a small load to the central heating boiler
  • Easy to install during the build of an orangery
  • Uses the whole of the screed as a massive thermal store

Minus points of wet underfloor heating:

  • Higher installation cost than other options
  • Relatively slow response time compared to radiators
  • Control gear, manifold and pump will need boxing in
  • Wiring will need to return to boiler
  • Pipework for both flow and return needed


Electric underfloor heating for orangeries (in-screed cable)

Electric underfloor heating (in-screed cable)

This type of heating utilises a continuous cable which is laid on top of the floor insulation prior to screeding.  This allows the heating cable to heat the whole screed which acts as a massive thermal store.  Once operating temperature is reached, only a small amount of heat is required to maintain energy.

The in-screed cable should be laid at the correct spacings to achieve a heating output of around 200 W/m².  This is sufficient to act as a primary heat source and more than adequate to heat a modern orangery.


Electric underfloor heating for orangeries (heat mat)

Electric underfloor heating (heat mat)

This type of electric underfloor heating is a 2-3mm cable that comes glued, snake fashion to an open webbed mat.  It is fitted after the floor is screeded.  Some manufacturers suggest laying a thin 10mm insulation board first, then the heat mat, and finally the floor tiles.

Whilst the system has a quick response time, there is virtually no thermal store so it is not as efficient as an in-screed system and will cost more to run.  A heat mat may struggle to act as a primary heat source, so while you may have a warm floor, the room might not reach the ideal room temperature on cold days.