For heat pump industrial drying, energy savings of 40 to 80 percent are often realistic compared to conventional hot air, exhaust air, or compressed air drying. In suitable applications, values of around 79 percent energy savings can also be achieved with heat pump-based condensation drying, depending on the product, water load, cycle time, temperature, and air flow. Operating costs decrease not only due to lower energy consumption but also due to reduced exhaust air losses, less scrap, more stable processes, and reduced rework. However, a reliable statement can only be made after an analysis of the existing drying process or through tests in the technical center.
Why Heat Pump Industrial Drying Saves Energy
Industrial drying is often one of the energy-intensive steps in production, surface treatment, cleaning, coating, food processing, pharmaceuticals, medical technology, or sludge drying. Classic systems often operate with high temperatures, a lot of fresh air, exhaust air, or compressed air. A significant portion of the energy used is lost with the warm, moist exhaust air.
In contrast, heat pump industrial drying utilizes the energy present in the process much more consistently. In condensation drying, moist air is drawn from the drying chamber, cooled, dehumidified, and then reheated. The dried process air is then returned to the dryer. This creates a largely closed circuit.
At HARTER, this technology is based on the Airgenex® heat pump module. Airgenex® refers to a heat pump-based air dehumidification process that generates extremely dry air at comparatively low temperatures and directs it specifically to the product. Crucial is not only the dehumidification but also the air flow: the dry air must reach exactly where moisture is to be absorbed.
What savings are realistic?
As a realistic guideline: If conventional hot air drying, an open exhaust air process, or a heavily compressed air-based drying system is replaced, energy savings of between 40 and 80 percent are often possible. In particularly well-suited applications, values around 79 percent energy savings can be achieved. However, such values should always be considered process-specific, not as a blanket promise.
Operating costs can also decrease significantly. Savings often arise not only in electricity or gas consumption but also in disposal, scrap, complaints, maintenance, hall climate, exhaust air treatment, and personnel costs. Especially in German production facilities with shift operations, not only the energy price per kilowatt-hour matters, but also how stably the process runs across early, late, and night shifts.
In practice, a comparison across several key figures is worthwhile. Relevant factors include energy consumption per batch, energy consumption per component, cost per operating hour, drying time, scrap rate, rework, and availability. For drying systems in industrial manufacturing, this holistic view is usually more meaningful than a mere comparison of connected load.
What factors influence savings?
The amount of savings depends on the initial situation. The more inefficient the previous process, the greater the potential often is. Particularly high savings often occur where a lot of warm exhaust air was previously discharged, compressed air was used as a drying medium, or excessively high temperatures were employed.
Important influencing factors include the water load, i.e., the amount of moisture that must be removed per batch or per hour. Equally important are material, geometry, bulk density, surface structure, temperature resistance, and desired residual moisture. Scooping components, blind holes, undercuts, or tightly packed bulk material place different demands than flat, easily accessible surfaces.
The mode of operation also matters. A system operating in three shifts saves absolutely more energy and costs than a system running only a few hours per week. For management, purchasing, and operations, the annual operating time is therefore a central factor in amortization calculations.
How does the technology affect operating costs?
Operating costs include more than just energy. A drying system incurs costs for electricity, gas, compressed air, maintenance, spare parts, operating effort, production space, scrap, rework, and downtimes. Heat pump industrial drying can influence several of these cost blocks simultaneously.
A closed process reduces exhaust air losses. This means less heated hall air needs to be replaced. In many companies, the hall climate also improves because less moist or warm air is released into the environment. This is particularly interesting when production areas need to be air-conditioned, ventilated, or monitored for occupational safety reasons.
Another point is process reliability. If drying functions independently of season, humidity, and hall temperature, the risk of fluctuating results decreases. This reduces rework and scrap. In industries with documentation requirements, approval processes, and quality audits, this stability is often just as important as pure energy savings.
Example Calculation for SMEs
A medium-sized surface treatment company currently dries cleaned or galvanized components using hot air and additional compressed air. The drying runs 4,000 hours per year. The previous process requires an average of 35 kW of thermal and electrical power. With assumed energy costs of €0.20 per kWh, annual energy costs amount to approximately €28,000.
If the process is replaced by heat pump industrial drying and the average energy requirement decreases by 60 percent, the energy share is reduced to approximately €11,200 per year. The direct energy cost saving would thus be about €16,800 annually. With 75 percent savings, it would be approximately €21,000 per year.
This calculation is deliberately simplified. In practice, connected loads, load profiles, electricity and gas prices, compressed air costs, maintenance, potential subsidies, production utilization, and quality costs must be considered. Nevertheless, it shows why companies with high operating hours and energy-intensive drying should consider industrial dryers based on heat pump technology early on.
What terms should decision-makers know?
Electroplating refers to a process in which metallic layers are electrochemically applied to components. After rinsing, cleaning, or coating processes, reliable drying is necessary to prevent stains, corrosion, or quality problems.
A technical center is a test area where real products are tested under controlled conditions. At HARTER, parameters such as temperature, time, humidity, air velocity, air volume flow, and air flow are checked there.
A drying system is the overall system consisting of the drying chamber, air flow, dehumidification, heating, ventilation, control, and interfaces to production. The pre-cooler pre-cools moist process air. The air cooler removes moisture from the air, which is discharged as condensate. The air heater brings the dehumidified air back to the desired process temperature. The process air fan moves the air between the heat pump module and the drying chamber. The dryer interface describes the transition where moist air is removed from the drying chamber and dry air is reintroduced.
Use Case: Energy Savings in a German Production Line
A company with 450 employees operates an automated cleaning line for precision parts. The stakeholders are management, production management, maintenance, quality assurance, purchasing, and the works council. The goal is to reduce energy costs, maintain stable cycle times, and prevent staining after cleaning.
In the existing process, results fluctuate between summer and winter. High humidity leads to more rework and occasional delivery delays. Production management wants to increase throughput, quality assurance demands reproducible drying results, and purchasing focuses on investment costs and amortization time.
The project first documents the current state: energy consumption, cycle times, part portfolio, residual moisture, scrap rate, and operating effort. Afterwards, tests are carried out in the technical center with representative components. Particularly critical geometries are deliberately included so that the later system reliably dries not only standard parts but also demanding variants.
Typical pitfalls include incomplete consumption data, underestimated compressed air costs, insufficient space in the line, missing interfaces for control, and uncoordinated approval processes. The works council can also be relevant if operating procedures, shift tasks, or qualification requirements change. If the project is properly prepared, heat pump drying can not only save energy but also stabilize the entire process.
Checklist for Economic Feasibility Study
Where Heat Pump Industrial Drying is Particularly Useful
The technology is particularly interesting for products that need to be dried safely, gently, and reproducibly. These include components after cleaning or electroplating, bulk goods, rack goods, baskets, trays, painted parts, precision parts, food, pharmaceutical products, and sewage sludge.
The industry overview clearly shows that drying should not be considered an isolated secondary process. It influences quality, throughput, energy demand, and sometimes even disposal costs. For example, in sewage sludge applications, weight and volume can decrease, which affects disposal costs. In pharmaceuticals and medical technology, however, reproducibility, low temperatures, and documented process reliability are often paramount.
In the food industry, controlled low-temperature drying can also be beneficial when product quality, hygiene, and energy efficiency are considered together. For decision-makers, it is important: the best solution does not result from a standard value, but from the product, process, and target variable.
Classification of Amortization
The amortization period is often between two and six years, but can be shorter or longer depending on operating time, energy price, previous technology, investment scope, and savings potential. Systems in multi-shift operation often amortize faster because annual savings are higher. For low operating hours, however, quality improvement may be more important than the pure energy cost calculation.
Funding opportunities can improve economic efficiency, especially when energy and CO2 are saved. Companies should note that funding applications usually need to be submitted before commissioning. Purchasing, controlling, and technical management should therefore collaborate early.
For heat pump drying solutions from HARTER, testing with original material is an important step. It helps to estimate technical feasibility, drying time, temperature window, and energy requirements more realistically.
Typical Follow-Up Questions
FAQ
How much energy can heat pump industrial drying save?
Energy savings of 40 to 80 percent compared to conventional drying processes are often realistic. In suitable applications, values around 79 percent can also be achieved. Crucial factors are water load, drying time, temperature, air flow, operating hours, and the previous process.
Are operating cost savings as high as energy savings?
Not always one-to-one. Operating costs also include maintenance, personnel, scrap, rework, compressed air, exhaust air technology, and downtimes. Therefore, operating cost savings can be lower or, in some cases, even higher than pure energy savings.
Why is compressed air often a cost driver in drying?
Compressed air is expensive because a lot of electrical energy is converted into heat during its generation. If compressed air is used extensively for blowing off or drying, operating costs quickly increase. A compressed air-free or compressed air-reduced solution can therefore be very economically attractive.
For which industries is heat pump industrial drying particularly worthwhile?
It is particularly worthwhile in energy-intensive, quality-critical, and cycle-bound processes. Typical areas include surface treatment, cleaning, electroplating, industrial production, food, pharmaceuticals, medical technology, and sludge drying. It is always important to test with the specific product.
What temperatures are common in condensation drying?
Many applications operate at low temperatures in the range of approximately 40 to 75 °C. This is particularly helpful for temperature-sensitive products, plastics, coatings, or precision parts. The appropriate temperature is determined process-specifically.
How can economic efficiency be checked before an investment?
First, actual consumption, cycle time, water load, scrap, and operating costs should be recorded. Then, drying tests with original products are useful. From the results, energy requirements, technical design, and amortization time can be derived much more reliably.
Can a heat pump drying system be integrated into existing processes?
Yes, integration into existing lines is often possible. Space conditions, material flow, control, safety technology, cycle time, and interfaces must be checked. The earlier these points are clarified, the lower the risk of later adjustments.
What role does air flow play in savings?
Air flow is crucial. Even very dry air is of little use if it does not reach the moist areas of the product. Appropriate air flow shortens drying times, improves quality, and increases the energy efficiency of the entire system.
