Mecalia DPAC/DI/MCL 150-Liter Floor-Mounted Buffer Tank

The Mecalia DPAC/DI/MCL 150-liter buffer tank, reference 06881, is designed to store cold or hot water from the primary circuit in heating and HVAC installations. Made of carbon steel, it operates at a maximum pressure of 3 bar and a temperature of up to 90 °C, making it especially suitable for systems with heat pumps, boilers, solar energy, or chilled water production equipment.

Its function is to increase the hydraulic volume and thermal inertia of the installation, helping to stabilize generator operation and temporarily store thermal energy. The 150-liter model is designed for vertical floor-standing installation, includes HCFC-free injected rigid polyurethane foam insulation, and features multiple connections to integrate the tank into different hydraulic layouts.

150-liter buffer tank for heating and HVAC

The Mecalia DPAC/DI/MCL 150 is intended to work with primary circuit water in thermal installations. It can be used with both hot and cold water, making it suitable for heating and cooling systems.

Applications considered by Mecalia include:

• Heat pumps and aerothermal systems.
• Boilers.
• Heating installations.
• HVAC installations with water chillers.
• Solar thermal energy systems.

Not suitable for domestic hot water

Mecalia expressly states that this tank is not suitable for DHW. It is intended exclusively for closed hydraulic circuits for heating or HVAC.

For this reason, it must not be used as a potable water storage tank or to directly store domestic hot water for consumption.

Made of carbon steel

The tank body is made of carbon steel, a solution especially suitable for closed primary circuits.

As this is a technical buffer tank and not a sanitary storage tank, it does not require the vitrified lining used in tanks intended for direct DHW storage.

Maximum working pressure of 3 bar

The DPAC/DI/MCL 150 is designed for a maximum working pressure of 3 bar.

Mecalia indicates that the corresponding safety valves with the appropriate setting must always be installed directly on the tank, in accordance with the applicable instructions and regulations.

Maximum temperature of 90 °C

The maximum working temperature declared by the manufacturer is 90 °C.

This range allows the tank to be integrated into both heating and cooling circuits, always within the operating limits of the rest of the system components.

Especially useful with heat pumps

In installations with a heat pump or aerothermal system, a buffer tank increases the total water volume available in the circuit.

When correctly sized, this additional volume can help stabilize flow rates and temperatures and reduce excessively short generator start-stop cycles.

The required capacity must be determined according to the heat pump manufacturer’s requirements, installed power, existing hydraulic volume, and distribution layout.

Suitable for heating and cooling

The tank can store cold or hot water from the primary circuit. Therefore, it can also be used in reversible systems that operate in heating during winter and cooling during summer.

Mecalia expressly includes its use in HVAC installations with water chillers.

Polyurethane thermal insulation

In the 150-liter model, Mecalia uses HCFC-free injected rigid polyurethane foam as thermal insulation.

The outer finish is skay. This insulating jacket helps reduce heat exchange with the environment, both when the tank contains hot water and when it operates in a cooling circuit.

Vertical floor-standing installation

Reference 06881 is specifically designed for vertical floor-standing installation.

Its overall dimensions are:

• Diameter: 500 mm.
• Height: 1,310 mm.

This format provides 150 liters of buffer volume while keeping the footprint relatively compact in plant rooms and technical spaces.

Weight of 56 kg

The DPAC/DI/MCL 150 has an empty weight of approximately 56 kg.

Once filled with water, the unit weighs significantly more, so it must be installed on a stable, level surface with sufficient load-bearing capacity.

1½" hydraulic connections

The tank features eight main female threaded 1½" connections, distributed at different heights to facilitate integration into various hydraulic schemes.

According to Mecalia’s technical drawing, these connections are intended for functions such as:

• Heating circuit flow.
• Heating circuit return.
• Flow from the generator or boiler.
• Return to the generator or boiler.
• Drain.
• Connection for auxiliary electric heater.

The presence of several inlets and outlets at different heights provides flexibility to configure the tank according to the hydraulic layout designed by the installer.

Five 1/2" sensor connections

In addition to the main hydraulic connections, the tank includes five 1/2" threaded connections for sensors.

These connections allow temperature probes to be placed at different heights in the tank when required by the system control.

Connection for auxiliary electric heater

The technical drawing includes a specific connection for an auxiliary electric heater.

This connection makes it possible to design configurations where a compatible heating element is needed. The presence of the connection does not mean that the electric heater is included with the tank.

Helps increase the system’s thermal inertia

By adding 150 liters of hydraulic volume to the circuit, the tank can temporarily store thermal energy and smooth out rapid temperature fluctuations between the generator and the emitters.

This feature is especially useful in installations with low water content, multiple circuits, zone valves that open and close, or generators that require a minimum hydraulic volume to operate correctly.

Mecalia 06881 technical specifications

• Brand: Mecalia.
• Reference: 06881.
• Model: DPAC/DI/MCL 150.
• Type: buffer tank.
• Capacity: 150 liters.
• Application: heating and HVAC.
• Fluid: cold or hot water from the primary circuit.
• Suitable for DHW: no.
• Operation: closed circuit.
• Material: carbon steel.
• Installation: vertical floor-standing.
• Maximum working pressure: 3 bar.
• Maximum working temperature: 90 °C.
• Main hydraulic connections: 1½" female.
• Number of main connections: 8.
• Auxiliary sensor connections: 1/2".
• Number of 1/2" connections: 5.
• Connection for auxiliary heater: yes.
• Insulation: injected rigid polyurethane foam.
• HCFC-free: yes.
• Outer finish: skay.
• Diameter: 500 mm.
• Height: 1,310 mm.
• Empty weight: 56 kg.
• Compatible with heat pump: yes.
• Compatible with boiler: yes.
• Compatible with solar energy: yes.
• Usable in cooling: yes.

Mecalia buffer tank for aerothermal systems and HVAC

The Mecalia DPAC/DI/MCL 150 provides 150 additional liters of hydraulic volume for heating and cooling installations, offering a particularly useful solution for aerothermal systems, heat pumps, boilers, and solar energy.

Its carbon steel construction, maximum pressure of 3 bar, temperature up to 90 °C, eight main 1½" connections, multiple sensor connections, and polyurethane insulation make it easy to integrate into professional thermal installations that need to increase circuit inertia.