Advantages and uses of the air-to-air heat pump

The air-to-air heat pump is a valid alternative for air conditioning in the home, both in summer and in winter. Being powered exclusively with electricity, it allows you to limit the use of gas for heating. Let's see together the advantages that its installation entails and what are the uses that can be made of it.

What is meant by air-to-air heat pump?

There are different types of heat pumps, the air-to-air one takes thermal energy from the outside air and transfers it to the inside rooms, always in the form of air. For example, air conditioners are often heat pumps, as they perform the dual function of cooling and heating.

How does the air-to-air heat pump work?

The main advantage of the heat pump, in terms of consumption and respect for the environment, lies in the fact that it uses a natural source - air, water or soil - to draw thermal energy and cool or heat. The heat pump, therefore, does not produce heat, but transfers it from one part to another using electricity. 

In particular, the air-to-air heat pump consists of an outdoor unit and one or more splits which are placed in the rooms. The operating cycle is as simple as it is effective. When we are in heating mode, in the outdoor unit a convector fluid is brought to a very low temperature, so as to absorb heat from the outside, and is transformed into gas by the evaporator. The gas reaches the compressor, which increases its pressure, generating an increase in temperature. Now the heated fluid reaches the condenser, from which the heat spreads throughout the rooms by means of the splits. 

If we are in cooling mode, the behavior is exactly the reverse: The fluid absorbs the heat from the inside and releases it outside, thus reducing the internal temperature.

How do you install an air-to-air heat pump?

An air-to-air heat pump air conditioner is a product that is easier to install than a system with a boiler. In fact, it does not require the preparation of flues, and maintenance is limited to periodic checks. A site inspection by a technician for the installation of an air-to-air heat pump air conditioner is not mandatory, but it is advisable to consult an expert for a verification – which can also be done via a telephone questionnaire – of the requirements necessary for installation.

The time and costs for installing an air-to-air heat pump can depend on several factors, including:

• the technological features of the product;
• the positioning of the pipes, which can be run through exposed ducts or embedded in the walls;
• the positioning of the outdoor unit, which is easier in the case of a house with a balcony or a garden.

In the case of installation with exposed ducts, the work takes a couple of hours; the time may increase depending on the size of the system. In the case of installation with concealed pipes, the installation time and related costs increase. Generally speaking, installing a basic air-to-air heat pump air conditioner costs approximately 800 - 900 euros, a figure that includes the supply of the machine and the installation. It is also possible to take advantage of dedicated incentives for the purchase.

Dimensions of air-to-air heat pumps

Regarding dimensions, air-to-air heat pumps are quite small: an indoor unit of approximately 34x100x21 cm and an outdoor unit of approximately 55x80x30 cm. Normally, one split unit is installed for each room to be air-conditioned, unless the area is so large that more than one is needed.

The seller will suggest the most suitable number of splits for each room in the house, but for a reference, you can consider this ratio: 120 bTu/h*cubic meter (a ratio valid for the average class of Italian homes, F, but it may vary depending on how well the house is insulated). Therefore, you can consider a 9,000 btu/h heat pump air conditioner for a room of approximately 30 square meters, while for a 35 square meter room, a 12,000 btu/h heat pump will be necessary. If the building is well insulated, you will get a better yield.

Based on the characteristics of the home (number of rooms to be air-conditioned, layout of the rooms, size, etc.), it is possible to configure the system by choosing a combination of so-called "monosplit" air conditioners (consisting of one motor and one split unit) and/or "multisplit" air conditioners, which instead consist of one motor connected to two or more split units.

Where to install the air-to-air heat pump?

As we have seen, the air-to-air heat pump consists of an outdoor unit and one or more indoor splits. The two systems must be connected, so when deciding where to install one or the other, it is necessary to evaluate the distances and the simplicity of connection. 

In particular, the outdoor unit must be installed in an easy to reach point, to carry out the necessary maintenance. Usually you choose to place it on the ground on the balcony/terrace, or on the wall on the facade. The important thing is that there is the possibility of discharging the condensate. It is advisable to avoid direct exposure to sunlight or closed and small places, which do not allow for good ventilation. Finally, the noise produced must be considered, which is amplified in small rooms.

What are the advantages of a heat pump?

Air-to-air heat pumps are increasingly popular for heating and cooling environments, let's see the main advantages they guarantee us.

Simple installation and use 

The installation of an air-to-air heat pump requires a limited number of structural modifications, ad hoc rooms are not required, nor the presence of a chimney. 

Moreover, having a single system for heating and cooling reduces the space occupied in the house. 

Environmental sustainability

The main energy source is air, without fossil fuels, and therefore, theenvironmental impact of an air-to-air heat pump is contained. The annual CO2 saving for an air-to-air heat pump is -251 kg.

Economic savings

On average, an air-to-air heat pump allows 45% savings compared to gas heating costs. If associated with a photovoltaic system, the savings on bills increase, in fact, by self-producing the electricity needed to operate the pump, heating and cooling costs are further reduced.

Furthermore, if the envisaged requisites are met, it is possible to benefit from state incentives which can be 50% in the case of restructuring (art. 16-bis Presidential Decree 917/86), 65% in case of energy requalification (art. 14 DL 63/2013) or 110% if you fall within the parameters of the so-called superbonus (art. 119 DL 34/2020).