UC Heating System

UC moves away from coal

Feasibility study and design management for a new boiler system

In 2018, the University of Canterbury commissioned a feasibility study of alternative heating sources for their campus. They wanted to get rid of their coal fired boilers and reduce their carbon footprint because almost 50% of their emissions were from burning coal.

UC issued a request for proposals to provide options for a more sustainable heating source. At the time our Director Steve was Technical Director of the Building and Places team at AECOM, who won the work. Steve began with several workshops to go through the university’s goals in detail. These workshops are vital because they flush out information not mentioned in the brief. The more time we spend understanding your needs, the better the outcome you’ll get.

UC’s existing boiler system is a district heating system, a centralised boiler plant that feeds every building on the campus. But heating loss from the vast network of pipes creates inefficiencies and the university has to generate more heat than it needs to deal with those losses. One way to improve efficiency is to have decentralised plant. Instead of one central boiler room, you create smaller networks where heating plant is nearer the buildings it serves.

Sustainable heating systems are more limited than you’d think

Steve and his team started out looking at a long list of 40 sustainable heating systems. But most were not feasible, either because the technology wasn't sufficiently developed or it wasn't supported in New Zealand. Heating is critical to the university, so they can’t take the risk of a system failing, and not being able to get spares or someone to fix it.

Steve shortlisted 20 systems to investigate in more detail. There was no one solution that delivered everything the university wanted, so he and his team developed a traffic light system that compared the risks and rewards of the different systems to identify the best of the bunch. They highlighted eight systems worth a further look, presented those to the UC team, agreed on a short list, and produced a feasibility study on the shortlisted systems.

UC settled on ground source heat pumps. These pump water out of wells in the ground and use that water in a refrigerant cooling cycle to generate heat. Ground source heat pumps are a more efficient version of the wall mounted reverse cycle heat pumps you find in most New Zealand homes. Domestic heat pumps circulate refrigerant between the heat pump and a unit outside. In winter they push heat from the refrigerant into the room, and in summer they push heat from the refrigerant outdoors. Ground source heat pumps function the same way, but water is a more efficient medium for heat transfer, so you get a better output.

A hybrid solution to buy time for building upgrades

Any hope this would be a straightforward project was dashed when Steve’s team discovered the university campus has many old single-glazed, poorly insulated buildings. This is a problem because sustainable heat sources don’t produce as much energy as coal fired systems. The highest temperature from ground source heat pumps is around 60°C, whereas coal fired systems crank out about 80°C. If your heating system can't produce as much energy, you need your buildings to be more efficient at retaining heat. So, to change to a more sustainable heat source the university needed to improve their buildings first.

Improving the university’s buildings and installing the new heating system is a 25-year programme of work with a budget of around $500 million. So, UC needed a longer transitional period with high temperature heat sources to give them time to upgrade their buildings. As an interim solution, Steve and his team proposed changing the university’s boiler fuel from coal to carbon neutral wood chips from sustainable plantations. This hybrid system reduces UC’s carbon footprint, while giving them time to upgrade buildings and install new heating without shutting the campus down.

A roadmap to transition UC to coal free

Steve developed a phased plan to change the existing boilers over to wood chip and install ground source heat pumps by grouping buildings together and installing a central plant system for each group. This helps the university move away from their central boiler house, reduce the load on their boilers, and transfer to their new system in manageable way.

The second stage of the feasibility study was a more detailed transition plan for the buildings, itemising plant to be installed and proposing staged timings. As part of this, Steve produced a diagram showing the steps UC need to take to retire their existing heating system and adopt a sustainable heating source. This roadmap gave the university council the project overview they needed to approve budgets. It was important to communicate the stages of the process clearly and concisely because the council are time poor.

From feasibility study to design management

A few weeks after Steve left AECOM and established Honoris, he got a call from the university saying they needed someone to manage design for the boiler installation project. So, he went in, sat down, talked about the design management support they were looking for, and agreed a scope of work. That’s how UC became our first client.

The design management project took about 18 months. We attended design team meetings, resolved design requirements, managed the various consultants and suppliers working on the project, identified potential risks, and kept the university team informed with weekly reports. The biggest part of a design manager's role is making sure that people are getting the info they need to progress the design. That can be tricker than you’d think in a large organisation like a university. Having us involved, ensured information flowed where it needed to go.

Engage us to do a feasibility study for your building services

Slotting new heating and cooling into an existing building or campus is rarely straight forward and building services are expensive, so it pays to get them right from the start.

One big benefit of this project was the depth of the research we did into sustainable heating systems and their pros and cons. This strong understanding of the technologies available has been invaluable as we help other organisations transition to sustainable building services.

So, if you’d like to book a services feasibility study for your building, sustainable or otherwise, get in touch. We’re here to help.