ASHRAE Journal - December 2019 - 55

COLUMN ENGINEER'S NOTEBOOK

team can participate with all performance and pricing
data fully transparent. This information is collected by
requesting equipment bids from manufacturers' reps
using a bid form that includes performance data as well
as a ﬁnal ﬁxed price. The design and construction team
can then transparently discuss and weigh the advantages and disadvantages of each bid option, including
price, energy performance, noise, space requirements
etc., and make a ﬁnal selection.
This approach is effective for selecting any equipment,
but it is ideal where any of the following is true:
* The speciﬁed product is unique, especially if it can
be bundled with other products.
* There are many different features among the available manufacturers that cannot be easily evaluated
without knowing and weighing the costs.
* There are signiﬁcant variations in performance vs.
price so arbitrarily setting a single design performance
in bid documents may not result in the best selection.
* Other considerations where a side-by-side comparison makes for a better selection than low bid.
Examples include chillers, boilers, custom air handlers, and large packaged air-conditioning units.
The procedure can be implemented in one of two
ways, either during the design phase or after the design
is complete.

Design Phase Selection

Selecting equipment during the design phase is the
recommended option since it allows the design team to
design around equipment selections without concern
about redesigns that might be necessary if the contractor proposes substitutions. The bid should occur
when equipment capacities are known and relatively
ﬁrm, typically right at the start of the Construction
Documents (CD) phase. Here is a summary:
1. Decide which equipment will be bid using this
approach.
2. Prepare equipment speciﬁcations, as with any
project. In general, the specs should not mandate speciﬁc performance, such as chiller efﬁciency. Efﬁciency
will be evaluated later along with other selection criteria. However, it is desirable to specify maximum sound
power levels since there are multiple ways to address
sound, as discussed in the air-handler selection example
below.
3. Prepare a bid form for each equipment type. The

form must include price and performance data and
should include other application data such as power
requirements, weights, delivery information, etc. Two
examples, chiller selection and custom air-handling
unit selection, are discussed below.
4. Send the specs and bid forms to selected manufacturers' reps with a ﬁxed bid period, typically two
weeks. The specs and forms usually include alternates
to either delete or add features the design team wants to
consider. Voluntary alternates from the bidders should
be encouraged. For large chillers, which are custom
equipment with an extremely wide range of price and
performance, bidders should be encouraged to make
multiple proposals. If a consulting engineer conducts
the bid, it is essential to make it clear that this bid is the
only bid for this equipment; there will be no opportunity
to rebid when the project is released for general contractor bidding. Reps who are not experienced with this process may consider this a "budget" and not provide competitive pricing, mistakenly thinking there will be an
opportunity later to provide the "real bid" to contractors.
It must be made clear that this is the "real bid." Also,
bidders should be allowed to deviate from the speciﬁcations in any way provided the deviations are spelled out
in the bid form. This ensures that the selection process
is not skewed to any one product. Deviations from the
specs are considered during the bid evaluation, just like
any other selection consideration.
5. Adjust pricing if there are secondary cost impacts of some options. For example, open-drive chillers require that a fan-coil be added in the chiller room
due to motor heat gain. As another example, most low
mass boilers require a minimum ﬂow bypass while a
higher mass boiler may not. Note that cost is only one
consideration so these adjustments may be rough order
of magnitude estimates (ROMs) provided by the project
estimator.
6. Collect the bids and compile into a single table to
allow side-by-side comparison of the various features.
Usually, the engineer also provides additional subjective
information in the table, such as relative maintenance
costs, prior experience with each product or manufacturer, etc.
7. Meet with all team members who care to participate to discuss the bids and make a selection. On
a p&s project where contractors are not yet on board,
the meeting would typically be just the engineer and
D E C E M B E R 2 0 19

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ASHRAE Journal - December 2019

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