Honeywell LCBS User Manual

LCBS CONNECT SOLUTION
31-00118EFS—01 12
Honeywell Integrated Economizer Control - High Limit and Changeover
Strategies
North America features widely different climates. ASHRAE and other code bodies recognize this fact and provide control
guidance. These organizations drive application and use of economizer systems regionally. These different climate zones
drive different economizer application practices. For example, air in Honolulu and Miami is far hotter, higher dew point
and has almost no capability to be used to augment the HVAC cooling process.
NOTICE
As a service contractor, you probably know what your customer's needs are. Continue to set controls how you see
fit. We haven't seen any building code or ASHRAE police roaming any U.S. streets, yet!
The information below describes the use of the following economizer strategies.
Strategy 1: Differential Enthalpy with Fixed Dry Bulb Temperature Limit
This technique can be used in all ASHRAE climate zones. Successfully applied, excellent energy savings can accrue to
building owners. LCBS Connect remote services alerting and analytics can help you fine tune settings to maximize
customer energy savings and maintain comfort.
How does it work? If there is a call for cooling and return air enthalpy is less than outdoor air enthalpy and the outdoor air
temperature is below high limit, changeover set point, RETURN air will be used to cool your customer's building. If there is
a call for cooling and return air enthalpy is GREATER than outdoor air enthalpy and the outdoor air temperature is below
high limit, changeover set point, OUTDOOR air will be used to cool your customer's building.
Enthalpy hysteresis is adjustable to make sure that you don't experience excessive enabling and disabling of the
economizer cycle potentially overusing the economizer actuator. It is advised that you don't change this value unless you
talk to a Honeywell distributor or customer support professional.
Strategy 2: Outdoor Air Enthalpy
This technique can be used in all climate zones. HVAC professionals like this method as it's relatively simple to deploy. As
with all economizer limit and changeover strategies, LCBS Connect remote services alerting and analytics can help you
fine tune setting to maximize customer energy savings and maintain comfort. There is an ASHRAE prescriptive value
suggestion at 28 LB/BTU changeover. Many folks find this a bit warm and could result in customer, client comfort issues.
How does it work? If there is a call for cooling and outdoor air enthalpy is less than outdoor air enthalpy set point and the
outdoor air temperature is below high limit, changeover set point, outdoor air will be used to attempt to cool your
customer's building.
Again, enthalpy hysteresis is adjustable to make sure that you don't experience excessive enabling and disabling of the
economizer cycle potentially overusing the economizer actuator. It is advised that you don't change this value unless you
talk to a Honeywell distributor or customer support professional.
Strategy 3: Differential Temperature
This technique is suggested to be used in zones 1B, 2B, 3B, 3C, 4B, 4C, 5A, 5B, 5C, 6A, 6B, 7, and 8. See map on page 16.
HVAC professionals like this method as it's relatively simple to deploy and understand. As with all economizer limit and
changeover strategies, LCBS Connect remote services alerting and analytics can help you fine tune setting to maximize
customer energy savings and maintain comfort.
How does it work? If there is a call for cooling and outdoor air temperature is less than return air temperature and the
outdoor air temperature is below high limit, changeover set point, outdoor air will be used to attempt to cool your
customer's building. If there is a call for cooling and outdoor air temperature is GREATER than return air temperature and
the outdoor air temperature is below high limit, changeover set point, RETURN air will be used to attempt to cool your
customer's building.
Temperature hysteresis is adjustable to make sure that you don't experience excessive enabling and disabling of the
economizer cycle potentially overusing the economizer actuator. It is advised that you don't change this value unless you
talk to a Honeywell distributor or customer support professional.
Strategy 4: Outdoor Temperature
This technique is suggested to be used in zones 1A, 2A, 3A, 4A, 5A, 6A, 1B, 2B, 3B, 3C, 4B, 4C, 5B, 5C, 6B, 7, and 8. See map
on page 16.

Honeywell LCBS Specifications

General

Brand	Honeywell
Model	LCBS
Category	Controller
Language	English