Waste Heat = Waste of Energy
and Money
What is the one form of heat that costs each industrial facility money and
energy, and serves no purpose at all? Waste heat.
Simply put, waste heat is any form of heat discarded from a process at a higher temperature than
the ambient levels in the facility. Examples of waste heat include exhaust gases, cooling water and
heat lost from heated products or hot equipment surfaces. With an estimated 20-50% of energy used
in industrial facilities lost in the form of waste heat, waste heat reduction is becoming increasingly
important to keeping costs down, margins up and emissions under control.
The first step to reducing waste heat is identifying its sources. This can be done by reviewing all
processes including all heat sources and heat sinks (requirements) in the facility. Special attention must
also be paid to existing processes or systems that have recently been replaced or modified to ensure
that all equipment is still functioning at maximum efficiency levels.
The best way of reducing waste heat is by eliminating the source outright.
Typical examples of this include:
Checking for and fixing steam leaks, and ensuring that steam traps are functioning properly
Inspecting and regularly maintaining insulation in pipes, vats, valves, ovens, etc.
Shutting down equipment and systems when they are not required or in use
Regular maintenance of equipment to ensure it is operating at maximum efficiency
Although eliminating the source of waste heat is the most direct
and cost-effective way of reducing it, it’s not always possible.
In these circumstances, waste heat recovery may present a
viable alternative.
Waste heat recovery is the process of collecting waste heat and
using it to fulfill a desired purpose elsewhere in the facility. Three
essential components are required for waste heat recovery:
1. An accessible source of waste heat such as combustion
exhausts, process exhausts, and cooling tower water.
2. A recovery technology such as a heat exchanger
or economizer.
3. A heat sink (or heat requirement) such as preheating raw
materials, boiler feedwater, combustion air, or space heating.
enbridgegas.com ⁄ industrial
[email protected]
Waste Heat = Waste of Energy
and Money
In addition to saving a significant amount of energy and money each year, many effective heat recovery
projects yield very attractive payback periods of six months to a year.
Considering the fact that capturing and reusing waste heat is an emission free substitute to losing
money on incremental energy requirements, the question becomes, why aren’t more facilities finding
ways to make use of their waste heat?
The answer is simple—it’s a matter of economics. There are a number of
factors that impact the economic feasibility of undergoing a waste heat
recovery project:
Where to put the recovered waste heat
• Whether it is used for process or thermal purposes, you must be able to make use of the waste
heat recovered for the project to be economically feasible
• The higher the temperature, the greater the potential to make use of the waste heat
Availability of waste heat i.e. intermittent, seasonal, continuous
• Continuous would yield the best results
Contaminants that may erode the heat recovery equipment in the facility
• May shorten the lifespan of the equipment reducing the economic feasibility of the project
To learn more about waste heat recovery and how to evaluate its economic feasibility in your
facility, join us at our upcoming Heat Recovery Workshop on June 7th at the International Centre
in Mississauga.
Contact your Enbridge Energy Solutions Consultant if you’re interested in finding ways to identify,
eliminate, capture and/or reuse waste heat in your facility.
enbridgegas.com ⁄ industrial
[email protected]