Written by Rikard · 14 years in construction and owner-side project management · €150M+ in governed project value.
A wall-mounted unit that cools a Greek living room in summer may also provide heating in winter if it is a reversible heat pump. Whether it costs less than an oil boiler depends on the unit, tariff, fuel quote, building and required heat output; the comparison should be run on those inputs.
Reverse-cycle is the term for it, and it is not a trick, it is a valve. A heat pump moves heat rather than generates it, extracting warmth from outside air, even air at plus 5 degrees Celsius still carries usable heat, and concentrating it indoors. Run the same refrigerant cycle the other direction and the unit extracts heat from inside the house and dumps it outside, which is cooling. One compressor, one refrigerant loop, one reversing valve, two jobs. This is why a heat pump condenser cooling a Greek apartment in August belongs to the same category of machine as the one heating a house through winter in the Peloponnese.
Choose the System Before the Brand
Brand and model choice should follow the system type, emitters, local service support, climate and property heat-loss assessment. Do not treat an editorial list as a Greek sales ranking or a statement that a model currently qualifies for subsidy. Historic heat-pump support is not a current approval. Our guide to heat-pump and solar support explains the programme checks to keep separate from equipment selection.
The first choice is system family. Reversible air-to-air units can heat and cool individual rooms. Air-to-water systems can serve radiators or underfloor heating, with design and operation depending on the selected equipment and existing emitters. Existing air-to-air units may contribute to winter heating if their capacity, controls and use suit the property; assess that before buying replacement equipment.
SEND THE HEATING SETUP BEFORE YOU BUY ANYTHING NEW
How to Compare Running Costs
Use this as a comparison method, not a quote. Insert the property’s current electricity tariff, delivered oil quote, equipment performance at relevant conditions and boiler-efficiency assumption; the result changes with those inputs.
For a hypothetical calculation, state the assumed electricity tariff, operating COP and required heat output. Divide electricity cost per kWh by the assumed COP to estimate heat cost per kWh. Replace every assumption with the property’s actual tariff and selected unit data before making a decision; this is not a current-price or savings guarantee.
For the same hypothetical calculation, state the delivered heating-oil quote, fuel-energy assumption and documented boiler efficiency. Divide fuel cost per litre by usable heat per litre to estimate heat cost per kWh. Do not substitute road-fuel prices or present an undated local oil price as current fact.
Compare the two hypothetical heat-cost results using the same required heat output and state every assumption. A heat pump can cost less per unit of delivered heat when operating efficiency and tariff support it, but the result varies by equipment, tariff, oil quote, building and use. ETS2 operation in 2028 does not establish a fixed retail-price increase for either comparison.
Choose a Consistent Indoor Setpoint
Choose the indoor setpoint for the occupants and use the same required heat output in both sides of the comparison. A different setpoint changes the demand calculation; it does not remove the need to use the property’s own tariff, fuel quote and equipment assumptions. If considering an energy-poor property bought at a discount, assess these cost inputs alongside the building’s condition.
Weighing a Heat Pump Against an Old Oil Boiler?
Before you commit to new equipment, we assess the existing system, the inputs needed for correct sizing and a property-specific running-cost comparison. A preliminary assessment does not confirm state-support eligibility. Start at kgnordic.com/contact or see the energy upgrade service.
A reversible unit that cools in summer can also be assessed for winter heating. Establish its capacity, operating conditions and the property’s cost inputs before assuming a saving over the oil boiler.
Frequently Asked Questions
Can the same heat pump that cools my house in summer also heat it in winter?
Yes, if the installed unit is reversible and is suitable for the conditions and rooms concerned. A reversing valve changes the refrigerant cycle between cooling and heating. Check the actual model and system design; central heating arrangements vary.
How should I choose a heat-pump brand and model?
There is no verified national model-level sales ranking in this review. Select a brand and model on system type, declared performance at relevant conditions, local service support, warranty and a property-specific design.
How much cheaper is a heat pump than an oil boiler in Greece?
There is no single current Greek saving figure. Compare electricity cost divided by operating COP with delivered-oil cost divided by usable heat per litre, using the property’s current inputs. Insulation, equipment sizing, boiler condition and use pattern all affect the result.
What coefficient of performance (COP) should I expect from a heat pump in a Greek winter?
Use the selected model’s manufacturer data at the relevant outdoor temperature and, for air-to-water systems, flow temperature. COP is test-condition-specific and seasonal performance also depends on installation and operation, so no generic winter COP is promised here.