Guide to purchasing an air source heat pump: A strategic investment in energy efficiency and living comfort in 2026

1. Introduction: A new era of energy transformation and living comfort

The Finnish building stock and residential energy solutions are in the midst of a historic transformation in 2026. Mitigating climate change, energy price volatility and tightening building regulations have driven property owners to look for solutions that not only cut costs but also improve the quality of living in a changing climate. In this equation, the air source heat pump (ASP) has risen from a marginal additional heat source to a key component of building technology, playing a critical role in both single-family homes and housing associations.

This comprehensive purchasing guide, written by Hesatek experts, is designed to serve the informed consumer, housing association board member, and real estate professional. It follows Hesatek's thorough "infra first" mindset, familiar from the company's electric vehicle charging solutions. We do not look at air source heat pumps as a single piece of equipment, but as part of a property's lifecycle management, energy efficiency strategy and indoor air quality assurance. Our analysis is based on 2025 legislation, including the new Construction Act, as well as the latest knowledge on refrigerant technology and market-leading equipment models.

1.1 Market situation 2026: Why right now?

The year 2026 is a significant watershed in the air source heat pump market for several reasons. First, fluctuations in the price of electricity in the exchange-traded electricity market have made the timing of energy use and the efficiency ratio (COP/SCOP) more economically significant than before. Air source heat pumps enable the bypass of expensive hours by reserving heat in structures and producing thermal energy with many times the efficiency compared to direct electricity.

Secondly, global warming has brought a new need to Finland: cooling. Summer heatwaves are no longer the exception, but the rule, which has changed the requirements for apartment building living. Cooling is no longer a luxury, but a health issue that housing companies must respond to. Thirdly, technology has developed to the point where devices are no longer just "functional", but smart, networked units that actively purify indoor air.

1.2 Structure and aim of the guide

The goal of this document is to break down the air source heat pump procurement process into parts that follow a logical and safe progression model:

1. Design starting points: How to analyze the object correctly?

2. Technical solution: What features are required of the device in Finnish conditions?

3. Permit processes and legal issues: How will the new Construction Act 2025 affect permit applications?

4. Financial analysis: Savings calculations and household deduction.

5. Implementation and installation: How to ensure technical quality?

6. Lifecycle and maintenance: How does the Fresh Wash method revolutionize maintenance?

Hesatek's service promise of "turnkey" delivery, a 24-month installation warranty and the most comprehensive maintenance concept on the market runs through the guide. Our goal is that after reading this, you will be able to make a well-founded, far-reaching decision that will increase the value and living comfort of your property.

2. Design starting points: Needs assessment and dimensioning

A successful purchase of an air source heat pump does not start with choosing the device, but with defining the need. An incorrectly sized device or one chosen for the wrong purpose is an investment that will not pay for itself.

2.1 Definition of intended use: Heating or cooling?

The first strategic choice is the primary function of the device. While most devices can both heat and cool, they are optimized for one or the other.

2.1.1 Single-family houses: Dominance of heating use

In detached houses, semi-detached houses and terraced houses, the main motive is almost without exception saving on heating costs. In this case, the device is required to have so-called "Hyper Heating" features or similar Nordic equipment. The most important thing is that the device is able to produce the amount of heat corresponding to its nominal output even at -15°C or -25°C. A COP value of +7 degrees alone does not tell the truth about the Finnish winter. The main heating system of the house must be taken into account when dimensioning: an air-source heat pump is a form of supplementary heating that works best alongside direct electricity or oil heating, cutting the need for purchased energy by up to 30–50%.

2.1.2 Apartment buildings: Cooling priority

The situation is the opposite in apartment buildings. In district heating buildings, heating does not achieve significant savings, and housing companies often prohibit the use of the device for heating due to the risk of condensation in winter. The most important features of an apartment building device are:

• Silence: The indoor unit must be almost silent (approx. 19 dB) so as not to disturb sleep.

• Compact size: Lack of space above doors is a common challenge.

• Condensation water management: Water generated during cooling operation must be safely drained to the sewer, not to the neighbor's balcony.

2.2 Situation analysis and sizing

Dimensioning is not just about calculating square footage. It is physics that takes into account air movement, thermal loads, and structures.

Video mapping as a modern tool

Hesatek utilizes modern video mapping (WhatsApp), which streamlines the process. The customer does not have to wait for a salesperson to visit their home, but an expert can assess:

1. Indoor unit location: Unobstructed airflow, distance to living areas (feeling of draft), power supply routes.

2. Outdoor unit placement: Wall material (wood vs. brick), bracket type (wall vs. ground bracket), condensation water routing.

3. Penetration: Wall thickness and material, possible obstacles (electrical wires, pipes).

The square-based rule of thumb and its challenges

A general rule of thumb is that 1 kW of cooling capacity is sufficient for approximately 15–20 square meters. However, this is a rough generalization. For example, large south-facing windows (the so-called "aquarium effect") can double the cooling requirement. The height of the room and the open plan layout versus a maze-like floor also play a decisive role. Hesatek's experts always size the device according to the power requirement, not just the surface area, ensuring that the device does not have to run at full power all the time, which would shorten its lifespan.

3. Technical solution: Equipment selection and features

Once the need has been identified, we move on to technical implementation. There are hundreds of models on the market, but Hesatek has chosen to represent only the so-called "Tier 1" manufacturers: Mitsubishi Electric, Daikin, Toshiba and Gree. This choice is based on long-term experience with equipment failure sensitivity, spare parts availability and importer support.

3.1 Thermodynamics and efficiencies (SCOP & SEER)

The heart of an air source heat pump is its ability to transfer heat energy. This is measured by two key numbers, understanding which is at the heart of the profitability of the investment.

• SCOP (Seasonal Coefficient of Performance): The seasonal coefficient of performance indicates how much heat energy the appliance produces per kilowatt hour of electricity over the entire heating season. Modern top-of-the-range appliances, such as the Mitsubishi Electric LN series, have a SCOP of up to 5.2. This means that the appliance produces more than five times more energy than it consumes. It is critical to check that the stated SCOP is calculated for a "cold climate" (Helsinki) and not for Central Europe (Strasbourg).

• SEER (Seasonal Energy Efficiency Ratio): The equivalent figure for cooling. Since the cooling season in Finland is short, SEER values ​​are often very high (8–10). This explains why cooling a home throughout the summer typically costs only 20–50 euros – the efficiency is so high that electricity consumption is marginal.

3.2 Refrigerants: R32 is the present day

In 2025, the market should no longer consider equipment with the old R410A refrigerant. The new standard is R32 , and there are good reasons for this:

1. Environmental friendliness: R32 has a GWP (Global Warming Potential) of 675, compared to 2088 for its predecessor. This is in line with the EU F-gas regulations and significantly reduces the carbon footprint.

2. Energy efficiency: R32 has better heat transfer capacity, which improves the efficiency of the device by approximately 10%.

3. Charge quantity: Less R32 is needed to produce the same output, making the units lighter and more compact.

4. Legal and permitting processes 2025: What has changed?

The new Construction Act (Construction Act 751/2023), which entered into force at the beginning of 2025, has brought significant changes to permit practices. The goal has been to reduce bureaucracy, but the situation with air-source heat pumps requires precision.

4.1 Permit to operate and "minor operation"

With the new law, many small construction projects are exempt from building permits. Installing an air source heat pump is often considered a "minor measure" that does not require a permit if it does not significantly affect the cityscape or neighbors.

• Main rule: In single-family housing areas, the installation of an air-source heat pump is generally exempt from a permit.

• Exceptions: If the building is protected, is located in an area specifically designated in the local plan, or the device is placed visibly on the street-facing facade, a permit or at least a notification procedure may still be required.

• Municipal differences: Although the law is nationwide, municipalities have the power to specify the regulations in their building regulations. For example, Helsinki, Espoo and Vantaa have traditionally had stricter interpretations of facade changes. Hesatek continuously monitors the building control policies of the Uusimaa municipalities and instructs the customer on the need for a permit in connection with the survey.

4.2 The special position of housing associations

In housing companies, the law has not changed the basic principle: the shareholder always needs the company's permission . This is because the installation of an air source heat pump is directed at structures under the company's control (external walls, facade).

Stages of the permit process in a housing company:

1. Modification work notification: The shareholder must submit a written modification work notification to the property manager well in advance of the start of the work. The notification must include information about the device, the installer (Tukes permits), the location and the treatment of condensate. Hesatek will deliver the completed documents as an attachment to the notification.

2. Company processing: The board or property manager processes the notification. The company may set conditions, such as a requirement for sound insulation or a specific location (e.g. below the balcony railing).

3. Agreement: Often the company requires the shareholder to sign an agreement in which the shareholder assumes responsibility for the maintenance of the device and any damage to the property.

4. Supervision: The company has the right and obligation to supervise the work. The costs of the supervisor are to be paid by the shareholder.

KKO's policies: Previous Supreme Court decisions have confirmed a shareholder's right to make changes (e.g. cooling) as long as they do not cause harm to the company or other shareholders. The company cannot therefore prohibit installation without a justified reason (e.g. a construction risk or significant noise nuisance).

5. Economy and Finance: Profitability of investment

An air source heat pump is a rare household appliance that generates money for its owner. In 2025, the financial equation will be even more attractive with the changes to the household tax deduction.

5.1 Savings calculations: Single-family house example

Let's look at a typical 120 m² electrically heated detached house in Uusimaa.

• Annual consumption without ILP: 20,000 kWh, of which heating approx. 15,000 kWh.

• Electricity price: Estimated average price (energy + transmission + tax) 15 cents/kWh = €2,250/year for heating.

• Effect of ILP: A properly sized device (e.g. Mitsubishi LN25) handles approximately 60% of the heating demand (9,000 kWh) with an efficiency of 4 (SCOP).

  • ILP consumes electricity: 9,000 kWh / 4 = 2,250 kWh.

  • Direct electricity takes care of the rest: 6,000 kWh.

  • New heating electricity consumption: 8,250 kWh.

• Savings: 15,000 kWh - 8,250 kWh = 6,750 kWh . In money terms, this is about €1,012 per year .

• Payback period: If the device costs €2,400 when installed, the investment will have paid for itself in less than 2.5 years. After this, the device will produce over €1,000 in annual "dividends".

5.2 Household deduction 2025: Two different levels

The tax authorities strongly support energy renovations, but in 2025 it is important to distinguish between two different categories of deductions.

1. Normal household deduction (Installation of an air source heat pump):

   • Reduction percentage for the work share: 35% (down from 40% in 2024).

   • Deductible: €150 (increased from €100).

   • Maximum: €1,600 / person.

   • Example: The price of the device is €2,400, of which the labor cost is €700. Deduction: €700 * 0.35 - €150 = €95 .

2. Giving up oil heating (Increased deduction):

   • If an air-source heat pump is part of a project that eliminates oil heating, the benefits are significantly greater.

   • Reduction percentage for the work portion: 60% .

   • Maximum: €3,500 / person.

   • Deductible: €150.

   • This increased deduction is valid until 2027. ²⁷

Hesatek clearly specifies the work portion in its invoices, which makes it easy to apply for a deduction in the MyTax service.

5.3 Financing: OP cooperation

Hesatek, in collaboration with OP, offers a flexible financing model. The customer can apply for financing directly online or with the assistance of a salesperson. The financing enables investment without a large one-time investment, typically in installments of around €50/month . When the monthly savings on the electricity bill are taken into account (up to €100–200 in the winter months), the purchase is often cash flow positive immediately: the savings are greater than the loan repayment.

6. Installation and implementation: Hesatek quality standards

An air source heat pump is not a "plug-and-play" device. Its operation, efficiency and lifespan depend entirely on the quality of the installation. Hesatek's installation process is standardized and based on the "infra first" philosophy, which ensures the device's operating conditions well into the future.

6.1 Installation day progress

1. Security and preparation: The installers arrive at the agreed time and begin by carefully securing the work area. Tidiness is a sign of professionalism.

2. Penetration: A hole is drilled in the wall for the refrigerant pipes and electrical cables. This is a critical step: the hole must be made at a slight angle outwards so that condensation water can drain out. The hole is carefully insulated to avoid cold bridges.

3. Installation of the units: The indoor unit is installed on a level surface without vibration. The outdoor unit is installed either on a wall mount (using high-quality vibration-damping rubber) or on a ground mount.

4. Plumbing and evacuation: The refrigerant pipes are connected with flange connections. After this, the piping is evacuated mechanically. This is the most important step in the process: evacuation removes air and moisture from the piping. If moisture remains in the system, it can freeze and break the compressor or react with the oil, acidifying the system. Hesatek will never correct this step ("sweeping" is strictly prohibited).

5. Electrical work: The device is always connected to the network by a licensed electrician. Hesatek's team has its own electricians, so there is no need to wait for outsiders.

6. Commissioning and guidance: The device is started and its operation (pressure levels, blowing temperature) is measured. The customer is given thorough guidance on using the remote control, cleaning the filters and installing the mobile application (e.g. MELCloud, Daikin Onecta).

6.2 Documentation and warranty

A commissioning report is prepared for each installation, which records the measured values, used materials and installer information. This is the customer's security and a prerequisite for the validity of the warranty. Hesatek grants a 24-month warranty for the installation work, and the devices have a 2–5-year warranty granted by the importer, depending on the brand.

7. Lifecycle Management: Maintenance and Fresh Wash

When an air-source heat pump operates, it draws in a huge amount of air. This carries dust, grease, spores and impurities that stick to the indoor unit's cell and fan drum.

7.1 Why isn't vacuuming enough?

Vacuuming the filters by the user is important, but it only removes surface dust. Over time, dirt "burns" into the heat exchanger and fan blades.

• Consequences: Dirt acts as an insulator, which reduces heat transfer. The device has to work harder to produce the same amount of heat, which increases electricity consumption and wears out the compressor. In addition, a dirty fan becomes unbalanced, starts to make noise and the bearings wear out. In the worst case, mold starts to grow on the device.

7.2 Fresh Wash® maintenance wash: The most efficient solution on the market

Hesatek offers a solution with the patented Fresh Wash® method , which is completely different from traditional compressed air cleaning.

1. Process: The device casing is dismantled. A waterproof protective tray is installed around the indoor unit.

2. Washing: The device is washed with plenty of water and a special biodegradable detergent using a pressure washer. The water and dirt drain into the tray, not onto the floor.

3. Results: Studies show that Fresh Wash restores up to 34% of the appliance's lost power. This is directly reflected in your electricity bill. In addition, indoor air is refreshed by removing microbial growth.

Hesatek recommends Fresh Wash maintenance every 2–4 years, depending on the location of the appliance (an appliance near the kitchen will get dirty faster from grease).

8. Summary: Why choose Hesatek as a partner?

Purchasing an air source heat pump in 2026 is one of the smartest things a property owner can do. It protects against rising energy prices, improves living comfort, and increases the value of the home. However, the market is wild, and quality varies greatly.

Hesatek's competitive advantages in a nutshell:

1. Comprehensive service: We provide everything: surveying, equipment, certified installation, electrical work and the best maintenance on the market (Fresh Wash). We are not just a "box mover", but a partner for the entire life cycle of the equipment.

2. Independence: We represent all the major brands (Mitsubishi, Daikin, Toshiba, Gree), so we genuinely recommend the device that best suits your needs, not the one that happens to be the most in stock.

3. Expertise and experience: Almost 30 years of experience and thousands of installations in Uusimaa guarantee that we are not practicing on your wall. Our customer satisfaction (4.6/5 stars) speaks for itself.

Do this:

1. Book a free video survey on our website. It only takes 15 minutes, there's no obligation, and you'll get an instant price estimate.

2. Choose a solution recommended by a professional.

3. Enjoy consistent heat and coolness – and a lower electricity bill.

Welcome to the ranks of satisfied Hesatek customers. Let's make your home energy efficient and comfortable – together.