Construction sites generate high heat loads within a short time: hydraulic power packs heat oil and water–glycol, electric drives emit waste heat, and closed process loops must remain temperature-stable. A construction site cooling system dissipates this heat in a controlled manner to the ambient air. This is especially relevant when Darda GmbH tools such as concrete demolition shears, rock and concrete splitters, combination shears, or steel shears run continuously and place high thermal stress on the hydraulics—such as in concrete demolition, rock excavation, tunnel construction, or special deployments with limited ventilation.
Definition: What is meant by construction site cooling system
A construction site cooling system is a mobile or temporarily installed setup for removing process heat. Typical designs are dry coolers (air coolers with heat exchanger and fans), adiabatically assisted dry coolers, and evaporative coolers. They operate in closed or open loops and keep media such as hydraulic oil or water–glycol within a safe temperature range to ensure viscosity, component service life, and performance. On construction sites, cooling systems are often coupled with hydraulic power packs or mobile hydraulic power units that supply Darda GmbH tools such as concrete demolition shears, rock and concrete splitters, concrete crushers, or multi cutters.
Design and operating principle on the construction site
At its core, a cooling system consists of a heat exchanger, fans, circulation pump, control valves, sensors (temperature, pressure, and optionally flow), a basic controller, and optional filtration. The heated medium (hydraulic oil or water–glycol) flows through the heat exchanger, transfers heat to the ambient air moved by the fans, and returns cooled to the loop. Closed-loop systems minimize contamination and fluid losses; open-loop systems (e.g., evaporative cooling) use the evaporation enthalpy of water and can achieve lower return temperatures at high ambient conditions—but require water quality management.
Design types: dry, adiabatic, evaporative
Depending on environment and required capacity, different concepts are used, each with pros and cons regarding energy demand, water consumption, noise, and maintenance effort.
Dry cooling (air cooler)
A finned-tube heat exchanger with fans transfers heat directly to the outdoor air. Advantages include low maintenance, no additional water demand, and simple installation. In very hot environments, however, the achievable supply temperature can be above the target temperature.
Adiabatic assistance
The intake air is pre-cooled via wetting media. This brings the air temperature closer to the wet-bulb temperature, significantly boosting cooling capacity on hot days. Water treatment, filtration, and proper operation must be considered.
Evaporative cooling (open/closed)
Evaporating water in a cooling tower yields very low cooling-water temperatures. This increases performance headroom but requires water and entails effort for water hygiene, drift eliminators, blowdown, and seasonal shutdown maintenance.
Use cases in concrete demolition and special deconstruction
In concrete demolition, gutting works and cutting, rock excavation, and tunnel construction as well as special deployments, hydraulic power packs often run at part load or full load—conditions typical of concrete demolition and special deconstruction. Darda GmbH tools such as concrete demolition shears, rock and concrete splitters, combination shears, multi cutters, steel shears, or tank cutters are operated over extended periods. Without sufficient cooling, the resulting waste heat drives up oil temperatures, reduces viscosity, accelerates seal wear, and increases the risk of leakage and cavitation. A properly sized cooling system stabilizes operating temperature and preserves overall system performance.
Sizing and dimensioning
Sizing is based on heat load, ambient climate, and target temperature. Practically, the removable heat is estimated from the energy balance: part of the input drive power becomes heat within hydraulics and components. Key parameters include:
- Hydraulic power, pressure level, and flow rate
- Overall efficiency of the power pack and tools
- Permissible medium temperature range (typical hydraulic oil 40–60 °C)
- Maximum ambient temperature, elevation, airflow management
- Noise limits and power supply (grid/generator)
- Water availability and quality (for adiabatic/evaporative)
Example estimate
A hydraulic power pack with 15 kW drive power and 80% overall efficiency turns about 3 kW into heat in the oil circuit; with a safety margin, a cooler rated at 4–5 kW is selected. With higher ambient temperatures or in tunnel construction with limited air circulation, a larger reserve is advisable. For oil circuits, as a guideline, moderate temperature lifts of 5–10 K across the heat exchanger help protect viscosity and sealing integrity.
Integration with hydraulic power packs and tools
The cooling system is integrated via supply and return lines into the hydraulic loop or via a separate oil–water plate heat exchanger. Variable-speed fan and pump control keeps the return temperature stable. Temperature sensors in the tank and downstream of the heat exchanger enable demand-based control. Quick couplings facilitate mobile use. With Darda GmbH tools such as concrete demolition shears and rock and concrete splitters, a robust hose routing with abrasion protection and a cold-start bypass are recommended so the oil can reach operating temperature in a controlled manner.
Operation, safety, and environmental aspects
During operation, positional stability, unobstructed air intake, and sufficient distance from dust sources are important. Filter mats in front of the heat exchanger reduce fouling. In enclosed spaces, the air cooler requires fresh-air supply and an exhaust-air path. For adiabatic or evaporative systems, water quality, blowdown, cleaning intervals, and proper shutdown procedures are essential. Fan noise levels must meet local requirements. Regulatory requirements for water hygiene, noise, and wastewater can vary by site and should be reviewed in advance.
Practical tips for use on site
- Position with favorable wind exposure; keep intake and discharge areas clear
- Regular visual checks for leaks, loose connections, atypical noises
- Set fan speed only as high as needed (save energy, reduce noise)
- Dust protection via filter mats; knock out/replace them frequently
- Frost conditions: use antifreeze in water–glycol; drain stagnant sections
- Store temperature limits in the controller; test alarms
- Plan reserve capacity for hot days; actively plan airflow in tunnel construction
Alternatives and differentiation
A dry cooler lowers the medium temperature toward ambient, but not below it. If the medium must be cooled significantly below ambient, a chiller with compression refrigeration is required. Many hydraulic power packs have integrated oil coolers; with high continuous load, multiple Darda GmbH tools operating in parallel (e.g., concrete demolition shears and combination shears), or unfavorable climatic conditions, an additional external cooling system can improve thermal stability.
Relevance to the application fields
In concrete demolition and special deconstruction, cooling systems keep hydraulic temperatures stable when Darda GmbH tools such as concrete demolition shears, steel shears, or multi cutters are under long-term load. In gutting works and cutting, they counter overheating when power packs run in poorly ventilated interiors. In rock excavation and tunnel construction, they support operation at high ambient temperatures and low air circulation. In natural stone extraction, they ensure reproducible process conditions throughout the day. In special deployments with limited power supply, variable-speed cooling helps finely dose output and sound levels.
Checklist for planning and selection
- Determine heat load (power, efficiency, load profile)
- Define permissible medium and ambient temperatures
- Select design type: dry, adiabatic, evaporative
- Consider noise, space, and energy constraints
- Plan water quality, antifreeze, and filtration
- Define control, sensors, and interfaces to the power pack
- Ensure transport, placement, and maintenance access
Technical metrics and sizing guidance
Key metrics include cooling capacity in kW at a defined ambient temperature, permissible temperature lift (ΔT) across the heat exchanger, air volume flow and static pressure, electrical power draw of fans/pumps, and the resulting return temperature. For hydraulic oil, a moderate return-temperature control is advisable that stays below critical limits and starts above the viscosity optimum to avoid condensation and cold-start issues.
Maintenance and service life
Regular cleaning of fins, checking fan bearings, visual inspection of fittings, and monitoring temperature trends increase availability. For adiabatic/evaporative cooling, water treatment, blowdown, seasonal disinfection, and documented flushing/shutdown before longer pauses are essential for safe operation. These measures are generally carried out in accordance with recognized rules of technology and cross-manufacturer recommendations.