S-Series Technical Manual
109
Cambridge Air Solutions
Overview
Energy efficient, Genuine Cambridge
®
direct
gas-fired heating equipment can comply with the
requirements of ANSI/ASHRAE/IESNA Standard
90.1-2010. Compliance is shown on the Cambridge
heater nameplate.
Purpose of ASHRAE Standard 90.1
ASHRAE Standard 90.1 provides minimum
requirements for the energy efficient design and
construction of new commercial buildings in the
United States. The standard covers the entire
building, setting minimum equipment efficiency
levels for components that may be used, rather than
setting standards for component manufacturing.
The provisions of this standard do not apply to
single family houses, low rise residential buildings
and buildings (or portions of buildings) that use
energy primarily for industrial, manufacturing or
commercial processes.
Compliance Requirements:
The following are required for Cambridge heaters to
comply with Standard 90.1:
• Controls (Section 6.4.3)
Total airflow of all heaters less than 10,000 cfm
- The Cambridge TSS Controller will meet the
standard. A properly configured building DDC
system with the necessary programming for zone
control, automatic shutdown and setback can also
meet the standard.
Total airflow of all heaters exceeds 10,000
cfm - The Cambridge TSS Controller with
optimum start control will meet the standard. A
properly configured building DDC system with
the necessary programming for zone control,
automatic shutdown, setback and optimum start
can also meet the standard.
Units intended to operate continuously - No
special controls are required to meet the standard.
• Damper (Section 6.4.3.4.3)
A damper is required on each heater. The
Cambridge Motorized Discharge Damper (MDD)
will meet the standard.
• Labeling (Section 6.4.1.5.1)
The heater must be labeled to indicate that it
complies with the requirements of the standard.
The nameplate of Cambridge heaters includes the
required labeling.
• Efficiency (Section 6.4.1.3)
Direct gas-fired heating equipment has no
minimum efficiency requirement. However
Cambridge certifies that its equipment has a
100% combustion efficiency (Ec) and a 92%
thermal efficiency (Et).
ANSI/ASHRAE/IESNA STANDARD 90.1
TEMPERATURE AVERAGING (TAS-2)
OPTION
(See Figure 3)
The TAS-2 option allows one thermostat to have two
sensing locations. Each enclosure has two thermistor
sensors prewired in series (see A). The sensor leads are
then connected to the thermostat in parallel (see B). The
thermostat display will show the average of the tempera-
tures at the two sensing locations. The TAS-2 is a unique
application. Consult the design drawing and/or your
Cambridge Representative for placement assistance.
Figure 2
Figure 3
Figure 1
