Hatch Air Source Heat Pump – Low Carbon Heating Systems

Currently, there is a demand for decarbonization projects to eliminate gas and oil heating as a source. The Hatch Air Source Heat Pump is specifically designed for these kind of decarbonisation projects.

Replacement Boiler Projects

Traditional gas and oil boilers, for high rises, hospitals and other institutions, are based on 180-190°F system supply water temperatures. The system loop, radiators and fan/coils are designed for the higher temperatures.

The Hatch Air Source Heat Pump is designed to achieve 180-190°F supply temperatures. Therefore, the heat pump is a direct replacement of the boiler.

Traditional heat pumps can only achieve 140°F supply temperatures. Therefore, the entire piping system, radiators and fan coils would also have to be replaced. To compensate for the lower water supply temperatures, the flow rates and radiators have to be increased so total heat capacity is met,
Thereby, increasing in the total capital expenditures and extending the return on investment (ROI).

By using the Hatch Air Source Heat Pump, it becomes a boiler replacement project instead of a heating system replacement project. This Greatly reduces the amount of capital expenditures, and bring the ROI into the proper range to make the project viable.

New Build

Hatch Air Source Heat Pump internals

With new build projects a lower leaving water temperature can be utilised which allows more options for the configuration of the Hatch Air Source Heat Pump. Fan, coils and radiators are designed for temperatures in the 140-150°F range it allows for more options in the compressor and heat pump configuration.

If floor loop heating is utilized then lower temperatures can be further lowered to 100-110°F. The lower leaving temperature will not require the heat pump to do as much work and, in turn, increase the coefficient of performance (COP) and reduce the ROI.

Domestic Hot Water Projects

The Hatch Air Source Heat Pump configuration for domestic hot water heating utilizes a double walled heat exchanger. It also uses a control strategy to vary the set point to boosts the water temperature to prevent Legionella.

Heating / Cooling Project

The Hatch Air Source Heat Pump can also be built as a reversing heat pump. Providing both heating and cooling water so that it is utilised through the year.

Heating / Cooling / Domestic Hot Water Project

The reversing Hatch Air Source Heat Pump can also be configured to have a dual glycol loop. At low ambient temperatures both the primary and secondary loop provide heating for the system. Alternately, at high ambient temperatures the primary and secondary loop provide chilled water.

Hatch Air Source Heat Pump internals

During the remainder of the year, the secondary loop which has its own circulation pump is directed to the domestic hot water loop to provide pre-heating. Depending on the location of the project this can be over 85% of the year.

Capacity Control

With the Hatch Air Source Heat Pump units, the capacity generates varies with the ambient temperatures. This will result in the capacity generated higher ambient temperatures being greatly increased. If this is not addressed then it will lead to excessive cycling of the compressor which in turn, will lead to greater fluctuation in the system supply temperature. With the Hatch Air Source Heat Pump there are several strategies that can be utilized to maintain the system temperatures while still allowing proper compressor cycling times.

The Hatch Air Source Heat Pump control strategy utilizes a dead band system which will maintain the supply temperature within 2°F. It will unload the stages as the load requires it.

With larger loads multiple units can be used which will give large turn-down capabilities. As well, an extra module can be added to allow for back-up (N+1).

Hatch Air Source Heat Pump capacity control chart

Defrost

Hatch Air Source Heat Pump internals

The Hatch Air Source Heat Pump utilizes defrost rides imbedded in the air coil. This will eliminate the need for reversing the system in the middle of winter, which would generate chilled water, undoing some of the heating load already generated. This way, the system capacity and COP remains high.

Source temperatures

Different geographical areas allow for different designs and operating conditions. The Hatch Air Source Heat Pump has been designed to operate as low as -25°F (-32°C). Depending on the requirements different strategies can be utilized to maximize the capacity and COP for these conditions.

Supply temperatures

A number of different design temperatures can be achieved with the Hatch Air Source Heat Pump’s from 120°F to 180°F the requirements for these depends on the application and different strategies can be utilized.

Potable water

The hot sheet air source heat pump can be built with double walled heat exchangers to be utilized for potable water.

As well, the controller is set up so that it will raise the temperature every time as designated by the user and to raise the setpoint up to 150°F to counteract the possibility of Legionnaires disease.

Alternate source points.

If ultimate source points are available like ground source or process loops, then the Hatch heat pump can be built as a water to water configuration. This way it will take advantage of higher source temperatures.

As well, if there is dual chilled water and hot water requirements such as sports arenas or process applications then the Hatch Water Source Heat Pump control strategy will be set up to control on both points.

The Capacity Range

The Hatch Air Source Heat Pump’s are available from 48 MBH to 340 MBH at 15°F ambient temperature. With the modular unit configuration, controlled by the master controller, the capacity can be increased to 4000 MBH (12 modules).

Foot Print

The Hatch Air Source Heat Pump’s lends itself to projects located in mid-density and high-density locations such as institutional buildings or high-rise buildings. The Hatch Air Source Heat Pump can be located on roofs, side yards, etc. It does not require large foot prints as utilised by other types such as ground source heat pumps.