woman inside bath
Photo: ROBERTO NICKSON/UNSPLASH

Heat pumps: a growing sustainable choice!

In renovations or new home constructions, the installation of heat pumps for heating sanitary hot water and climate control is gaining more prominence. But why have they become viable and eco-friendly options?

Heat pumps are an ecological revolution, capable of extracting up to 75% of the energy they consume from ambient air or geothermal energy. These conscientious solutions are ideal for replacing systems that use fossil fuels, such as boilers, for sanitary hot water (AQS) or heating.

Let’s start by understanding what they are, how they work, and where they can be applied.

A heat pump is a device that transfers heat from one place to another, using electrical energy for this transfer.

For example, a refrigerator operates on the same principle: the internal pump transfers heat to the environment where it’s installed, allowing the interior of the appliance to reach low temperatures, even negative in the freezer area. It’s noticeable that the back of the refrigerator ends up being warmer.

The heat pump comprises a refrigeration circuit with a compressor, evaporator, condenser, and expansion valve. These elements form a circuit where a gas circulates and, through compression and expansion (phase changes), absorbs and releases energy. The cycle determines the origin and destination of this energy.

There are different types of heat pumps, varying according to the energy source used, such as air, water, or geothermal.

Let’s explore those systems that are increasingly becoming a popular choice for both hot water and home heating!

Air-to-water equipment for producing sanitary hot water and climate control in homes

By using heated or cooled water circulating, for example, in radiant floor systems or fan coil units, these solutions can also include heating sanitary hot water together, enabling the heating of both water and the home with a single appliance.

Heat pumps only use electricity to transport energy, unlike energy-producing-based climate systems, such as electric radiators. This technology achieves efficiencies higher than 100%, significantly reducing electricity costs. For instance, the consumption of 1 kW can result in the production of 8 kW, and in some cases up to 9 kW.

The ability to achieve high efficiency makes heat pumps essential for reducing energy consumption, leading to a considerable annual reduction in electrical costs. Each kWh of electricity can transport an even greater amount of energy, promoting remarkable efficiency and contributing to a significant reduction in electrical consumption.

The configuration of the system depends greatly on the type of building and its specifications.

A central concern for all types of heat pumps is the gas used.

In recent years, there has been a significant change in this regard. The R32 gas and previously the R410A were widely discussed. A new gas, R290, is gaining prominence in some brands. With a much lower Global Warming Potential, this refrigerant complies with the F-gas regulation, which aims to reduce the use of harmful gases by 2030.

In terms of durability, heat pumps have an average lifespan of between 15 and 20 years, although this depends on factors such as regular maintenance. Despite requiring little maintenance, an annual check by an installer or service brand partner is essential to maximize their longevity.

For the ideal installation, the outdoor unit of a heat pump should be placed in a location with access to plenty of air and without nearby foliage. This not only allows for adequate air intake but also facilitates maintenance and cleaning services.

When determining the necessary power output, especially for systems like radiant floor heating, it’s essential to assess the heating requirements according to the area to be heated.

As a general guideline, a typical approach involves considering an average of 4 kilowatts (kW) of power for every 100 square meters of space.

However, this estimation can vary based on several factors such as the insulation quality, climate conditions, and individual preferences for desired comfort levels.

For larger spaces or areas with higher heat loss, this rule might slightly adjust, aiming to ensure adequate warmth distribution without overloading the heating system.

For AQS, in terms of power in kilowatts (kW) for a heat pump, the amount of required hot water can impact the size and capability of the system. The hot water demand, expressed in litres per person or litres per day, can affect the power needed to heat that quantity of water to the desired temperature.

Ultimately, consulting with a professional installer or heating specialist can help tailor the power calculations more precisely to suit the specific needs and characteristics of the property.

In summary, heat pumps emerge as a vital option for heating and AQS, offering an environmentally conscious alternative to traditional systems. The evolution of refrigerant gases, in line with environmental regulations, marks a crucial point in the industry, driving the transition to lower-impact gases.

With a considerable lifespan and requiring little maintenance, these systems promise efficiency and durability. However, proper installation and regular maintenance are essential to ensure their optimal performance.

When considering the future of heating technologies, heat pumps take on an increasingly relevant role in the pursuit of sustainable and effective solutions.

By Isa Conceição

Isa Conceição is the CEO of Soren – Renewable Energy Solutions, based in Almancil. She assists individual customers and small businesses seeking renewable energy solutions across Portugal. +351 910 030 423 | [email protected] | www.soren.pt