2.5: HVAC Systems Control

(35 maximum points possible)

2.5.1 Automation Systems (15 points)

GREEN GLOBES #2.5.1.1 Is there automation system controllability for energy systems (e.g. programmable thermostats, time clocks, occupancy sensors, etc.)? 

• Yes (10 points) 
• No (0 points)

Assessment Guidance

For this criterion the space should have independent control and/or monitoring capability for systems that affect energy usage, lighting and thermal comfort. Either single controls per unit or programmable access to a central Building Automation System (BAS) would be sufficient, as long as the master BAS does not override zone programming. Small, constant systems like single toilet exhausts and plug loads need not be controlled by the BAS, though the BAS should carry the necessary fault alarms for building systems.

GREEN GLOBES #2.5.1.2 Can the heating, ventilation and air-conditioning serving interior zones be controlled independently of the heating, ventilation and air-conditioning serving adjacent spaces that are not part of the interiors project? 

• Yes (5 points) 
• No (0 points) 
• N/A

Tooltip

The tenant space either has its own dedicated HVAC systems or the space systems are extensions of a larger building HVAC system. Check “Yes” if there are dedicated HVAC systems controllable by tenants. Or check “Yes” if the heating, cooling, and ventilation loads of the space are served by building HVAC systems, are controlled by the tenants, and the loads of other spaces do not limit the HVAC systems capacities or efficiencies. NOTE: Independent control of HVAC systems, as used for a tenant space, is an eligibility requirement for SI certification.

Assessment Guidance

The purpose of this criterion is to ensure that tenants have direct control over how their space heating, cooling, and ventilation requirements are met. If the building’s central HVAC system serves multiple zones, including tenant spaces, the tenant needs to have independent control over how the central HVAC system serves the tenant space. If adjacent spaces, for example, induce large cooling loads from a server room, or adjacent spaces require over-ventilation of the tenant space because supply air cannot be modified by the SI tenant, then this criterion cannot be met.

2.5.2 Domestic Hot Water Heaters (20 points)

GREEN GLOBES #2.5.2.1 Are the new hot water heaters tankless instant hot-water heaters or do they meet the efficiency requirements of ANSI/ASHRAE/IES Standard 90.1-2010? 

• Tankless instant hot-water heaters (10 points) 
• Meets ANSI/ASHRAE/IES Standard 90.1-2010 (10 points) 
• No (0 points) 
• N/A

Tooltip

Mark “N/A” if hot water is centralized for the whole building, and the tenant has no control. If the tenant purchases water heating equipment—e.g. for a break room—then either Yes the equipment is tankless and/or complies with ASHRAE Standard 90.1-2010, or No the equipment is neither.

Assessment Guidance

This criterion is also considered N/A when the central boilers are used to produce domestic hot water via a heat exchanger.

References 

• ANSI/ASHRAE/IES Standard 90.1-2010

GREEN GLOBES #2.5.2.2 Are all building gas domestic hot water heaters equipped with intermittent electrical igniters and low NOX burners? 

• Yes (10 points) 
• No (0 points) 
• N/A

Tooltip

Mark “N/A” if there are no domestic hot water heaters dedicated to the space.

Assessment Guidance

Natural gas water heaters can have electric ignition instead of a constantly burning pilot light. The electric ignition can be of the intermittent type that will only light the pilot (and then main burners) when the system calls for heat. This saves on auxiliary natural gas usage.

When fossil fuels are burned, nitric oxide and nitrogen dioxide are produced. These pollutants initiate reactions which result in the production of ozone and acid rain. The nitrous oxides (NOx ) come from two sources: high-temperature combustion (thermal NOx ) and nitrogen bound to the fuel (fuel NOx ). For clean-burning fuels like natural gas, fuel NOx generation is insignificant. Almost all water heater manufacturers offer models with low NOx or ultra-low NOx burners.

During Stage I, provide specifications and/or product submittals showing all non-electric domestic water heaters have intermittent electrical igniters and have low-NOx burners.

This criterion is also considered N/A when the central boilers are used to produce domestic hot water via a heat exchanger.

© 2020 Green Building Initiative, Inc. ALL RIGHTS RESERVED.