GEOTHERMAL

Canadian commercial refit utilises heat pumps

The use of Nordic heat pumps results in 50 per cent reduction in energy costs after building refit

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Maritime Geothermal produces ground-source heat pumps under the Nordic brand name and the range includes its W Series Commercial line. These heat pumps are offered in a range of sizes up to 70t and are described by the company as "a perfect choice for eco-friendly commercial buildings".

The large-scale W Series Commercial geothermal liquid-to-water heat pumps gather heat from the ground and distribute it through large commercial buildings via in-floor heat or fan coils. The process can also be reversed to provide cooling in the summertime.

Nordic W Series Commercial geothermal heat pumps are the company's largest heat pump and are designed for hot water production in commercial buildings. They are ideal for large-scale radiant in-floor heating applications, swimming pool heating, and ice rink cooling. They are available with a reversing valve for heating and cooling in a single unit and come with integrated phase protection as a standard feature. The W Series Commercial is available in capacities from 9t up to 70t. Typically, several medium-sized units are selected and installed in parallel.

An example of this type of installation is the 5151 Terminal Road building in Nova Scotia, which recently had an eco-friendly retrofit. Property owner Emera Inc., which is the parent company of Nova Scotia Power, moved dozens of employees and its executive team from the Nova Scotia Power building on the Halifax waterfront to the building upon completion the multimillion-dollar renovation.

The building used to be heated by the waste heat from the old Nova Scotia Power plant across the road, however, when that plant was decommissioned, the heating costs for the building skyrocketed. In order to counter this, the building went through a major retrofit of the cladding and windows to improve energy efficiency, and a new heating system was installed. It now uses seawater as its heating and cooling medium and has reduced its energy costs by 50 per cent.

One of Emera's senior project managers explained that the Terminal Road building now showcases energy innovations such as taking water from Halifax Harbour to heat and air condition the building. The company expects to see a 50 per cent reduction in its energy bills, based on the performance at its Nova Scotia Power building, where similar reductions have been seen. Key to these significant reductions is the installation during the refit of seven 70t Nordic W Series Commercial water to water heat pumps in parallel to provide a total of 490t of heating and cooling capacity. These units are BACnet compatible and use a Delta Controls system for building management.

Due to the application in which these heat pumps were to be used the Nordic W Series have some significant features that made them most suitable for use in a building refit. The units have a small footprint, in vertical configuration they can fit through standard single doors. In addition, the welded and reinforced frame means they can be lifted into place with a forklift from either the end or the side, which made it easier to get them into position at the Terminal Road site.

Two separate R410a circuits with a common water circuit, in each unit ensure the best part and full load efficiency and best oil management for the lowest operating cost. Also for increased reliability and efficiency, the W Series heat pumps feature dual shell scroll compressors that offer high tolerance for flooded starts, next-generation PVE oil.

There are also dual refrigerant circuits, which are clearly separated for ease of service. The electronic control board with an external digital user interface and BACnet communications means that the units can be easily connected via a USB port for laptop connection using the free software provided by Maritime.