Installing a heat pump in a commercial building

What types of commercial heat pump are there?

• Packaged rooftop heat pumps. Self-contained units that replace gas rooftop units, common on single-storey retail and offices.
• Variable refrigerant flow systems. One outdoor unit serves several indoor units, so zones heat and cool separately.
• Air-to-water heat pumps. They supply hot water for radiators, fan coils or floor loops, and can work alongside an existing boiler. See hybrid dual-fuel systems.
• Water-source loops. Many heat pumps share one water loop, and a boiler or heat source tops it up.
• Ground-source systems. A borehole or horizontal loop supplies steadier heat, at a higher first cost, as described in the geothermal installation process.

The right choice depends on the building, the heat and cooling loads and the available space. The air-versus-ground trade-off is in air-source versus ground-source heat pumps.

How do you design for a cold climate?

Start with a proper heat loss and cooling load calculation for the building as it is now, not the old equipment size. The method is explained in heat pump load calculation. Then test the design at the local winter design temperature. Capacity and efficiency of air-source units fall as it gets colder, so a design that works at 0 degrees C may fall short at minus 30, a point covered in heat pump sizing for cold climates and the cold-climate heat pump guide.

Commercial buildings also have internal gains from people, lighting and equipment, and ventilation loads that can dominate. A heat pump may handle most of the year and a backup boiler or electric heat the coldest hours. Ask the designer to show the share of annual heat each source supplies.

What site checks come before installation?

• Electrical service. Heat pumps add load, and the panel, transformer and utility connection may need upgrading. Ask the utility about timelines, which can be long.
• Structure. Rooftop and wall-mounted units add weight and snow loading.
• Noise and setbacks. Outdoor units can be loud, and local bylaws may limit placement near neighbours.
• Drainage and defrost. Defrost water needs somewhere to go that will not freeze into ice on walkways, see heat pump defrost and noise.
• Existing distribution. Ducts, pipes and radiators must work with the new supply temperature.
• Controls. Integration with the building automation system, and a clear sequence for when the backup runs.

Technicians who handle refrigerants must hold the required certification, and electrical and mechanical work needs permits and inspection. Ask each contractor for their licence details and references.

How does the installation go from start to finish?

1. Feasibility and load study, with a written proposal.
2. Design, drawings and equipment selection.
3. Quotes compared on the same scope, see how to compare heat pump quotes.
4. Permits and utility approvals.
5. Delivery, crane lifts if needed, installation, wiring and piping.
6. Commissioning: testing airflow, refrigerant charge, controls and safeties, with a written report.
7. Handover and training for the building operator, plus a maintenance plan.

Work is often staged so the building keeps heat during the change. Maintenance is covered in the heat pump maintenance checklist, and funding in how to check heat pump rebates, noting that commercial programs differ from residential ones.

What does a district-scale example add?

Drake Landing Solar Community in Okotoks, Alberta, ran its district loop at roughly 40 to 50 degrees C, a range that also suits many heat pump systems. Its Energy Centre, described on the Energy Centre page, housed the plant, the pumps and the controls that kept 52 homes supplied. The commercial lesson is that low-temperature distribution, good controls and a clear commissioning record decide how well a system works. The project was wound down from about 2020, and the ongoing maintenance of a system is as important as the installation itself.

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