Vitocal 100-AW AM2V Models 020028, 034043 and 051078

Outdoor Air to Water Heat Pump, Indoor Distribution, and Control Unit

Heating Capacity: 20.5 to 58 MBH 6 to 17 kW

Cooling Capacity: 1.4 to 4.3 Ton 5 to 15 kW

 

The Vitocal 100-AW AM2V heat pump is designed for heating/cooling of a building and heating domestic hot water.

The unit consists of two modules: Outdoor unit and Indoor unit.

 

Outdoor unit

The working principle of the unit is to capture heat from the environment and to transfer it to the heating circuit in the building. The low-temperature heat of the air is transferred through an evaporator to the heat pump system filled with a refrigerant, which turns into a gas as it evaporates. From the evaporator, the gas is drawn in by the compressor, which raises its temperature during its compression and directs it to the condenser. In the condenser, heat is transferred to the refrigerant, which fills the central heating system, and the cooled liquid flows through the expansion valve and returns to the evaporator, after which the whole process starts again. In the case of cooling, this cycle is reversed, and the heat is extracted from the building and discharged outside.

 

Refrigeration circuit

All the components of the refrigeration circuit are located in the outdoor module, including the refrigeration circuit controller with an electronic expansion valve. Depending on the operating conditions, the compressor power is adjusted by means of an inverter. When the space cooling function is activated, the refrigeration circuit is reversed.

 

Plumbing system

The indoor and outdoor modules are connected to each other via heating medium hydronic lines. A high-efficiency circulation pump (secondary pump) built into the indoor module supplies the heating medium to the secondary circuit. A central 3-way diverter valve: “heating/DHW heating” is responsible for switching between space heating and hot tap water heating. Heat pump controller The entire heating system is monitored and controlled by the heat pump controller. The heat pump controller is integrated into the indoor module. Communication between the indoor and outdoor modules takes place via a communication bus.

 

Indoor Unit

The working principle of the unit is based on the demand-dependent capacity control of the heat pump compressor with an activation of the electrical auxiliary heater via the controller of the indoor module. The indoor module controller regulates the heating output according to a preset heating curve. If the heat pump is not able to cover the building’s heating demand on its own, the controller automatically activates the electrical auxiliary heater which, together with the heat pump produces the desired heating medium temperature.

 

Outdoor temperature ranges for air-to-water heat pumps

Air-to-water heat pumps use the outdoor air as the heat source. Operation is only efficient within certain outdoor temperature ranges, e.g. between -13°F and 113°F (-25°C and +43°C). If the upper temperature limit is exceeded or the lower temperature limit has been reached, heat pumps switch off periodically. A corresponding notification appears on the heat pump controller. To cover the heat demand for space heating and tap water heating beyond the temperature limits, the heat pump controller automatically switches on the available auxiliary heating equipment, e.g. electric auxiliary heating, if necessary.

 

Required equipment

A communication bus cable between the outdoor unit and the indoor unit. Recommended: LiYY 2 X 22 AWG (0.34mm2) Maximum: LiYY 2 X 18 AWG (1.5mm2)

 

Installation with heating/cooling buffer storage tank

 

Space heating

The heat pump may heat up to 2 heating circuits: 1 heating circuit without a mixer and 1 heating circuit with a mixer.

 

Space cooling

The heat pump may cool up to 2 cooling circuits.

 

Connection to the hydronic system

The Vitocal 100-AW AM2V series heat pump can operate in a closed-loop hydronic system (the minimum heating medium pressure is 8 PSI [0.5 bar]).

The hydronic installation must be carried out in compliance with the applicable standards. The pipes connecting the heat pump to the indoor unit must have an internal diameter to ensure an adequate flow of the heating medium (see technical data table).

Flexible piping must be used to connect the heat pump to the hydronic system to prevent the transmission of vibrations to the system. The heating medium pipes and connections must be thermally insulated. Do not switch off the unit when the outdoor air temperature is below freezing. This will protect the condenser of the outdoor unit from damage. If there is a risk of power failure, the heat pump heating circuit must be isolated from the hydronic module by means of an additional exchanger and the heat pump heating circuit must be filled with an antifreeze. A prerequisite for the warranty is an installation of a solids separator at the unit inlet. The hydronic installation must be made in such a way that the indoor unit can be operated in the heating circuit without the outdoor unit (according to the following installation diagrams). This will ensure the operation of the heating system in the event of a failure of the outdoor unit.

 

Water quality Treatment for Vitocal feed water should be considered in areas of known problems, such as where a high mineral content and hardness exist. In areas where freezing might occur, an antifreeze may be added to the system water to protect the system. Please adhere to the specifications given by the antifreeze manufacturer. Do not use automotive silicate-based antifreeze. Please observe that an antifreeze/water mixture may require a backflow preventer within the automatic water feed and influence components such as diaphragm expansion tanks, radiation, etc.

 

Maximum antifreeze content is 50% for the Vitocal 100-AW.

 

Refer to the manufacturers specifications when determining derate based on glycol concentration. Do not use sulphur-containing Vitocal feed water. Check pH-level after some operating time. It should be in the range from 8.2 to 9.5. If it is not, please take appropriate measures. Total permissible hardness of the fill and top-up water - 70 ppm. Do not use antifreeze other than specifically made for hot water heating systems. System also may contain components which might be negatively affected by antifreeze.

Check total system frequently when filled with antifreeze. Advise system operator/ultimate owner that system is filled with a glycol mix. The heating contractor must provide a SDS (Safety Data Sheet) for the antifreeze used to the system operator/ultimate owner.

 

NOTE: In some applications having glycol levels LESS THAN 30%, there may be a chance of algae blooms leading to clogged strainers and heat exchangers.