ASHRAE Journal - May 2020 - 68

COLUMN ENGINEER'S NOTEBOOK

is used, and that buildings themTABLE 2 Mapping Ellen MacArthur Foundation (EMF) technical cycles and preemptive challenges to current practice
within HVAC industry.
selves can regenerate resources
BUSINESS
TECHNICAL CYCLE OR
EXAMPLES OF CURRENT PRACTICE WITHIN HVAC INDUSTRY
for reuse in the material or
MODEL
PREEMPTIVE STRATEGIES
energy streams or to restore the
Substitute Material Plastic and PEX piping, eco-friendly insulation, low ODP/low GWP refrigernatural environment. Before
ants, cardboard ductwork
Circular
materials and energy enter the
Virtualize
Converged
building
network, IoT technologies,
Design
manufacturing stream, two
building information modeling, virtual design and construction, optimization
cutting patterns for computer numerical control (CNC) sheet metal machines
preemptive strategies stand as
Share
District/campus energy Systems
prompts to designers:
Maintain/Prolong
Preventative
maintenance,
material
quality
specifications, continuous com* Substitute Materials: can you
Circular
missioning,
automatic
fault detection and diagnostics
Use
substitute materials for increased
Reuse/Redistribute Refrigerant recovery, heat recovery, high cycles of concentration in cooling
longevity of service?
towers
* Virtualize: can you provide
Refurbish/Remanufacture
Parts
recovery
during
demolition,
air
handler
in-situ
refurbishment
Circular
an equivalent virtual action in
Recovery
Recycle
Commodity and scrap metal recycling, utility "buy-back" programs
lieu of one requiring material or
energy consumption?
The implications of these scenarios imply not only
Working down the diagram toward the right-hand side,
changes to design principles but may also require
the circular cycles in the technical realm give a framework
changes to the business models used in the construcfor understanding where the HVAC industry is already
tion, HVAC manufacturing and service maintenance
active, as noted in Table 2.
industries to incentivize collaboration, reduced
material use, preventative maintenance, longevity
Example: Circular Manufacturing:
of reliable high-performance use and new models of
14
3D Printing for Material Optimization
procurement.
The University of Maryland has prototyped a 3D direct metal
printed heat exchanger that is fabricated more quickly, weighs 20%
Example: Circular Joint Venture:
less, and performs 20% more efficiently than a traditionally manuAir Conditioning as a Service (ACaaS)18
A Singapore-based energy service company provides its
factured equivalent.
clients with air conditioning as a service in a design-buildExample: Circular Manufacturing:
operate-maintain (DBOM) model, using Internet of Things
Resource Efficiency in New Circulator Design15
(IoT) feedback to run the systems for optimal performance
A Danish pump manufacturer redesigned its manufacturing proand to significantly reduce energy consumption. Resolving the
cesses and circulator pump design to achieve an 87% reduction in
question of ownership of a chiller plant asset versus access to
pump weight and has begun a take-back program for remanufaca cooling service means that the clients can avoid the up-front
turing or recycling. (p. 12)
cost of facilities experts and construction, while ensuring a
predictable "pay-as-you-use" annual cost to fit into the operaExample: Circular Energy Sourcing:
tional budgets.18
Deep Sea Cooling16
The State of Hawaii granted access to allow an energy service proExample: Circular Joint Venture:
vider to draw deep sea water from the ocean to cool 40 buildings in
Rooftop Greenhouse Reduces Building Air-Conditioning
the downtown Honolulu area. This is estimated to achieve drastic cuts
Loads19
A Montreal-based farm provides produce picked and delivin electricity use and potable water consumption, resulting in an estiered daily to local customers from 3.7 acres (1.5 ha) of greenmated reduction in carbon emissions by 84,000 tons per year.
houses built upon existing commercial rooftops. Benefits to the
In addition to the items noted above, the Chartered
farm include harvested rainwater for hydroponic agriculture
Institution of Building Services Engineers has begun
and the energy cost reduction from using waste building heat.
development of a technical guidance document to
Benefits to the building include the insulative layer caused
explore a circular framework via five scenarios as noted
17
by the farm that reduces heating and cooling loads and the
in Table 3.
68

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