What Does Air to Air Mean in Heat Pumps?
The term "air-to-air" defines both the source of the heat and the method of its delivery, setting it apart from air-to-water or ground source systems.
- Air Source: The system extracts low-grade thermal energy from the external air. This process works effectively even when temperatures fall below 0°C.
- Air Delivery: Unlike other systems that heat water for radiators, the warmth is released directly into the living space as conditioned air through internal wall-mounted or ducted fan coil units.
How Does an Air-to-Air Heat Pump Work?
The operation is based on the vapour compression refrigeration cycle:
- Heat Extraction (Outdoor Unit): The outdoor unit draws in air. A cold refrigerant circulates through a coil, absorbing the ambient heat and evaporating into a low-pressure gas.
- Compression: The electric compressor raises the pressure of the gas, dramatically increasing its temperature.
- Heat Distribution (Indoor Unit): The hot gas travels to the indoor blower unit, where a fan blows room air over a heat exchanger transferring heat directly to the air.
- Cooling Mode: In summer, the cycle reverses: the indoor unit extracts heat from the room air, and the outdoor unit expels that heat outside.
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Air to Air Heat Pump Ireland Prices and Grants
- Total Installed Cost (Excluding Grants): For a medium-sized home requiring a multi-split system (one outdoor unit feeding 3-4 indoor units), typically €8,000 to €18,000.
- Grant Support: The SEAI offers grants of up to €7,500 (including the €4,000 Renewable Heat Bonus for fossil fuel replacement).
- Cost After Grant: Typically €500 to €10,500, depending on the system size and bonus eligibility.
- Running Cost Savings: Annual running costs are very low, often €800 to €1,200 for space heating in 2026.
Are Air to Air Heat Pumps Worth It?
Yes, air to air heat pumps are an excellent investment, especially when seeking a fast, efficient, and dual-purpose solution without major structural modifications.
- Superior Efficiency: Running costs are drastically lower than gas, oil, or electric resistance heating.
- Dual Functionality: Provides highly efficient cooling, increasingly valuable in Ireland.
- Speed of Installation: Often 1-2 days and less disruptive than other heat pump systems.
- Zonal Control: Individual indoor units can be controlled separately.
Long-Term Costs and Savings of Air-to-Air Heat Pumps
| Heating System | Initial Cost (Net after grant) | Estimated Running Cost Over 25 Years | Total Estimated Cost (25 Years) |
|---|---|---|---|
| Air-to-Air Heat Pump | €500 - €10,500 | €16,000 - €23,000 | €16,500 - €33,500 |
| High-Efficiency Gas Boiler | €3,500 - €5,000 | €35,000 - €55,000 | €38,500 - €60,000 |
| Electric Radiators | €1,500 - €3,000 | €75,000 - €130,000 | €76,500 - €133,000 |
Future-Proofing and Lifespan
- System Lifespan: Typically 15 to 25 years, significantly outlasting most modern gas or oil boilers (10-15 years).
- Carbon Tax Hedge: Relying solely on electricity insulates homeowners from inevitable future carbon tax increases on fossil fuels.
- Property Value: Installing a modern renewable system improves your home's BER certificate, contributing to increased property value.
How Do Air-to-Air Heat Pumps Compare to Other Heating Systems?
| Heating System | Price per kWh input | Efficiency (COP) | Price per kWh output | Annual Heating Energy Cost |
|---|---|---|---|---|
| Electric Radiators | €0.2900 | 100% | €0.290 | €4,350 |
| Oil Boiler | €0.115 | 75% | €0.153 | €2,295 |
| Gas Boiler | €0.1200 | 75% | €0.160 | €2,400 |
| Air to Air Heat Pump | €0.2900 | 400% | €0.072 | €1,080 |
| Air to Water Heat Pump | €0.2900 | 375% | €0.077 | €1,155 |
Save on Your Home Heating Bills Today!
Our heating experts at Selectra can help you save on boiler services, heat pumps, and home heating oil — for free.
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This is a free call from Ireland. Selectra agents can assist you with comparing and switching energy providers on weekdays between 9 am and 5.30 pm.
What Are the Disadvantages of Air to Air Heat Pumps?
| Disadvantage | Description | Mitigation Strategy |
|---|---|---|
| No Domestic Hot Water | The system delivers only conditioned air; it cannot heat shower and tap water. | Pair with a solar immersion heater or dedicated solar thermal system. |
| Air Movement/Noise | Heat is distributed via fans, creating air flow and minor fan noise. | Choose units with low-noise sleep modes and ensure appropriate sizing. |
| Aesthetic Impact | Internal wall-mounted units can be bulky. | Consider ducted systems or slimline, modern units placed above doorways. |
| Zonal Penetration | Heating is most effective directly in the room with the unit. | Install multi-split indoor units in all primary living areas and bedrooms. |
Frequently Asked Questions About air-to-air heat pumps
Maintenance is minimal compared to a boiler. Clean the indoor unit's air filters monthly. A professional should service the system every 1-2 years, checking refrigerant charge, cleaning the outdoor coil, and ensuring electrical connections and fan motors operate correctly.
The defrost cycle is a normal part of operation in cold weather. When temperatures drop, the system automatically enters a defrost cycle for about 5-10 minutes, briefly reversing the refrigerant flow to melt ice on the outdoor coil. During this time, the indoor unit will stop blowing warm air.
Yes, one outdoor unit can heat an entire house using a multi-split system. This involves one large outdoor unit connected to multiple smaller indoor units placed in different rooms. Each indoor unit operates independently, allowing different temperatures in different zones.