Waste Heat as an Asset

Source and Sink Have to Match

Waste heat recovery only works when the source and the sink make sense together. That sounds simple, but most failed concepts break down somewhere in that match. A good waste heat opportunity needs a few things to line up: temperature, timing, distance, utilization, and practical engineering.

Temperature

Not all heat has the same value. A megajoule at 40°C is not the same as a megajoule at 400°C. The lower the heating temperature your building can accept, the more useful low-grade waste heat becomes.

This is why low-temperature hot water, radiant systems, ambient loops, and modern heat-pump-ready buildings matter.

Timing

A source of waste heat that exists at noon is only useful if the load exists at noon. If the source and sink do not overlap, you either need storage, a network, or a different business case.

This is where annual techno-economic modelling matters more than peak load thinking.

Distance

Heat does not move for free. Pipes, pumps, trenching, controls, heat losses, rights of way, and maintenance all show up eventually. A project that looks obvious can fall apart once distance and constructability are included.

Utilization

The money is not in the equipment size. The money is in the useful heat recovered over the year. A small system that runs often can beat a large system that sits idle.

Practical Engineering

Controls matter. Parasitic loads matter. Maintenance matters. Water quality, fouling, access, asbestos, crane placement, and phasing can change the answer.

This is where “technically possible” becomes either “buildable” or “not worth it.”

The Economics of Electricity in Ontario

One of the liveliest discussions was around economics. In Ontario, displacing natural gas with electricity is not automatically favourable. Electricity is high-grade energy. In thermodynamic terms, it is closer to exergy than fuel.

So if we use electricity to recover heat, we need to use it wisely. That usually means:

• Lower temperature lift.
• Higher COP technology.
• Smart controls.
• Avoiding high-cost electricity periods where possible.
• Checking the business case across the whole year, not just one design point.

Lessons from Case Studies

The case studies helped make this real. At UBC, waste heat from lab exhaust in the Earth and Ocean Sciences building is recovered and used to support heating at the Centre for Interactive Research on Sustainability. The lesson is source and sink adjacency.

At district scale, thermal networks can unlock diversity. One building may need cooling while another needs heating. A network lets that exchange happen across more buildings, more hours, and more operating conditions.

A System Design Problem

Waste heat recovery is a system design problem.

1. Find the source.
2. Find the sink.
3. Check the temperature.
4. Check the timing.
5. Check the distance.
6. Check the controls.
7. Then choose the technology.

Free Resources

I also shared three free resources for anyone working on this topic:

• Waste Heat as an Asset: Presentation material and technical notes from the talk.
• Heat Harvest: A high-level screening tool for estimating waste heat potential from common urban and infrastructure sources.
• Heat Harvest DC: A technical and economic screening tool focused on data centre waste heat recovery.

My hope is that more engineers, planners, owners, and policymakers start treating waste heat less like an unavoidable loss and more like a design variable. Because in many buildings and campuses, the heat is already there. The real question is whether we can match it to something useful.

Presented At

This material was presented to Professional Engineers Ontario (PEO) chapters:

• Professional Engineers Ontario, Toronto Humber Chapter: Waste Heat as an Asset, May 7, 2026. View PEO event page
• Professional Engineers Ontario, Scarborough Chapter: PEOSC Technical Seminar No. 1, April 20, 2026. View PEO event page

Also Published On

• LinkedIn: Waste Heat as an Asset. Read on LinkedIn