ASHRAE Journal - May 2020 - 28

ROUNDTABLE

FIGURE 2 Energy recovery ventilator.

Fresh Air to
Inside

Stale Air to
Outside

A requirement was added for energy recovery ventilators in non-transient (apartments and condominiums,
but not hotels) dwelling units (Figure 2).
A definition was added for series energy recovery,
which is a technology that provides significant energy
conservation in warm, humid climate zones.
A requirement was added for occupied-standby mode
ventilation shutoff. "When a zone is scheduled to be
occupied, and an occupant sensor indicates no occupants are within the zone." This became possible after
Standard 62.1 (IAQ) allowed zero ventilation in unoccupied zones, even if scheduled to be occupied. Airflow
is allowed when zones are outside of their temperature
limits.
Energy Recovery Chillers for Hospitals
Limited to: Acute Inpatient hospitals with 24 hr operation and chilled water capacity at design conditions
>300 tons (1055 kW), and that have simultaneous heat
and cooling above 60°F (16°C) outside air temperature.
Some climate zones are exempted. The size requirement
is for 7% of the design capacity at design conditions, not
including standby chillers.
A requirement was added for indoor pool dehumidifier energy recovery.
Air Curtains are now permitted in lieu of vestibules in
some climate zones and some building heights. This will
require coordination between mechanical engineers,
electrical engineers, and architects. Who will specify the
air curtains?
Motor selection was simplified and made more able to
handle ECMs and motors that are not rated in BHP.
Some of the Guideline 36 (Hight Performance
Sequences of Operation for HVAC Systems) sequences
have started to be incorporated into 90.1. In my opinion,
incorporating these sequences can save both first and
operating costs for our clients.
28

ASHRAE JOURNAL

ashrae.org

M AY 2020

IMAGE COURTESY OF AMERICAN ALDES

Stale Air
From Inside

Fresh Air
From Outside

Q3: The 2019 edition of Standard 90.1 includes
significantly enhanced verification, testing, and
commissioning requirements. Can you help designers, contractors, and building owners understand
those requirements and their impact on design and
construction?
Leonard Sciarra: There are a few things to note on
the new commissioning requirements. First there
are two levels of requirements: (1) Verification and
functional performance testing (FPT) is required
for all buildings. (2) commissioning is only required
in larger or more complex buildings, so only 20% of
U.S. buildings will require full commissioning. The
following buildings require only verification and
FPT:
1. Buildings, additions, or alterations with less than
10,000 ft2 (930 m2) of conditioned space and combined
heating, cooling, and service water heating equipment
totaling less than 960,000 Btu/h (281 kW) in capacity.
2. Buildings or portions of buildings that use the
Simplified Approach Option for HVAC Systems in
Section 6.3 (limited to buildings 25,000 ft (2300 m2) in
size).
3. Dwelling units.
4. Nonrefrigerated warehouses.
Another improvement with the new FPT/commissioning requirements is that the reporting requirements are consistent across disciplines and located in
Section 4 (the administrative section), while the specific items that may need to be tested or verified are in
each specific section (mechanical, envelope, lighting,
etc).
Commissioning and function performance testing do
not take the place of inspections, which cover the basic
level of compliance. However, inspections may be part
of an FPT or commissioning program and may be performed by the Authority Having Jurisdiction, the A/E
team, contractor or trade partner, or owner or owner's
representative. So, on each building project, discussion
around the inspection process should occur.
Reid Hart: Generally, the functional performance
testing and verification requirements have not
changed since the 2016 edition. However, requirements have been clarified, and functional testing
added for service water heating controls, power, and
other equipment. Informative Appendix H makes it

https://www.ashrae.org/

ASHRAE Journal - May 2020

Table of Contents for the Digital Edition of ASHRAE Journal - May 2020