2016 Title 24 Codes & Standards Enhancement (CASE) Proposal

ASHRAE Electricity Savings – Direct Digital Control (DDC) May 20th, 2014

Scott Bailey, EIT ASWB Engineering 2501 Chambers Road, Suite 103, Tustin CA (714) 731-8193

Stakeholder Meeting: Agenda • • • • • • • •

Code change overview Measure impacts Code change history Summary of current code requirements Typical practices Methodology for savings analysis Initial data and findings Specific stakeholder requests

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Proposed Code Change Overview • Proposed code change would add mandatory requirements for Direct Digital Control (DDC) systems to be installed in certain building applications • Based on ASHRAE 90.1-2013 (Section 6.4.3.10) requirements

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Proposed Code Change Overview Direct Digital Control (DDC) • Title 24 Definition: Direct Digital Control is a type of control where controlled and monitored analog or binary data, such as temperature and contact closures, are converted to digital format for manipulation and calculations by a digital computer or microprocessor, then converted back to analog or binary form to control mechanical devices.

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Measure Impacts • Applies to all new buildings, additions and retrofits (alterations) except for very small buildings where DDC would not be cost effective • These mandated controls will have capabilities that will facilitate energy management and energy saving measures: – Collect data from input and output points – Intercommunicate between zones, air distribution, heating and cooling plant controllers – Graphically display data and trends 5

Measure Impacts Proposed TABLE 120.2-A DDC Applications and Qualifications (based on ASHRAE 90.1-2013)

BUILDING STATUS

APPLICATION

QUALIFICATIONS

Air-handling system and all zones served by the system Chilled-water plant and all coils and terminal units served by the system Hot-water plant and all coils and terminal units served by the system Zone terminal unit such as VAV box

Individual systems supplying more than three zones and with fan system bhp of 10 hp (7.45 kW) and larger Individual plants supplying more than three zones and with design cooling capacity of 300,000 Btu/h (87.9 kW) and larger Individual plants supplying more than three zones and with design heating capacity of 300,000 Btu/h (87.9 kW) and larger Where existing zones served by the same air-handling, chilled-water, or hot-water system have DDC

Alteration or addition

Air-handling system or fan coil New air-handling system and all new zones served by the system New or upgraded chilledwater plant

Where existing air-handling system(s) and fan-coil(s) served by the same chilled- or hot- water plant have DDC Individual systems with fan system bhp of 10 hp (7.45 kW) and larger and supplying more than three zones and more than 75% of zones are new Where all chillers are new and plant design cooling capacity is 300,000 Btu/h (87.9 kW) and larger

Alteration or addition

New or upgraded hotwater plant

Where all boilers are new and plant design heating capacity is 300,000 Btu/h (87.9 kW) and larger

New building New building

New building

Alteration or addition Alteration or addition Alteration or addition

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Proposed Code Change History Why are we proposing this measure? • This measure is being proposed to provide buildings with the control infrastructure to: – improve building HVAC operations – implement energy efficient measures – manage energy demand

• The proposed measure is derived from ASHRAE 90.1 (2013) Section 6.4.3.10

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Proposed Code Change History • ASHRAE includes additional energy saving measures when DDC is installed to the zone level, which will be incorporated into Title 24: – VAV Setpoint Reset – static pressure setpoint shall be reset based on the zone requiring the most pressure – Multiple-Zone VAV System Ventilation Optimization – reduce outdoor air intake – Hydronic Variable Flow Systems – differential pressure setpoint shall be reset based on value position 8

Current Code Requirements • 2013 Title 24 does not require the installation of DDC systems in buildings • IF a DDC system is installed to the zone level voluntarily, the following Title 24 requirements apply: – Demand Control Ventilation – Title 24 Section 120.1(c) • Building must have demand control ventilation

– Automatic demand shed control – Title 24 Section 120.2(h) • Controls must be programmed to allow centralized demand shed for non-critical zones 9

Typical Practices • Medium and large buildings – Typically built with an Energy Management Control System (EMCS). – Typically the EMCS are digital and therefore are considered to be DDC systems, so existing Title 24 requirements for demand control ventilation and automatic demand shed controls would apply – Would benefit from new DDC requirements for Setpoint Reset Logic

• Small buildings (except very small buildings) – Not typically built with EMCS or DDC system – Would benefit from DDC systems and measures 10

Methodology for Savings Analysis • Energy and Demand Impacts – The energy saving methodology takes into consideration the following: • Typical building size and HVAC system • Minimum compliant DDC to Title 24 • Impact of Climate Zone

– Energy savings will be model using eQUEST software simulating representative building types and sizes across all California climate zones

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Assumptions for Savings Analysis • Current Assumptions: – Cost to implement is based on size of building and number of HVAC zones – The proposed measure will have the greatest impact on small buildings because medium and large buildings are already in compliance • May limit the potential energy savings because proposed standard is holding the line of what is already typical practice

– Most savings will be derived from Demand Control Ventilation and Setpoint Reset Logic – Savings from automatic demand shed controls will not be included because participation in an IOU demand response programs is not required 12

Initial Data and Findings • Initial Findings: – Analysis is still underway – Initial findings indicate savings will be low relative to other measures because: • buildings most likely impacted will be of small size • medium and large buildings will have to comply with the proposed standard, but typically these buildings are in compliance except for the new DDC Setpoint Reset Logic, so there maybe some savings.

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Requests from Stakeholders • We would greatly appreciate any information you are able to provide to assist our efforts – technical information – market trends and forecast – cost data

• If you would like to provide us with any additional feedback or information, send an email to [email protected] 14

Questions? Scott Bailey ASWB Engineering (714) 731-8193 [email protected]

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Excerpt from 2013 Title 24 Section 120.1(c)3 – Mandatory Ventilation Requirements 3. Required Demand Control Ventilation. HVAC systems with the following characteristics shall have demand ventilation controls complying with 120.1(c)4: A. They have an air economizer; and B. They serve a space with a design occupant density, or a maximum occupant load factor for egress purposes in the CBC, greater than or equal to 25 people per 1000 ft² (40 square foot or less per person); and B. They are either: i. Single zone systems with any controls; or ii. Multiple zone systems with Direct Digital Controls (DDC) to the zone level. EXCEPTION 1 to Section 120.1(c)3: Classrooms, call centers, office spaces served by multiple zone systems that are continuously occupied during normal business hours with occupant density greater than 25 people per 1000 ft² per Section 120.1(b)2B, healthcare facilities and medical buildings, and public areas of social services buildings are not required to have demand control ventilation. EXCEPTION 2 to Section 120.1(c)3: Where space exhaust is greater than the design ventilation rate specified in Section 120.1(b)2B minus 0.2 cfm per ft² of conditioned area. EXCEPTION 3 to Section 120.1(c)3: Spaces that have processes or operations that generate dusts, fumes, mists, vapors, or gases and are not provided with local exhaust ventilation, such as indoor operation of internal combustion engines or areas designated for unvented food service preparation, or beauty salons shall not install demand control ventilation. EXCEPTION 4 to Section 120.1(c)3: Spaces with an area of less than 150 square feet, or a design occupancy of less than 10 people per Section 120.1(b)2B. EXCEPTION 5 to Section 120.1(c)3: Spaces with an area of less than 1,500 square feet complying with Section 16 120.1(c)5.

Excerpt from 2013 Title 24 Section 120.2(h) – Mandatory Control Requirements for Space Conditioning Systems (h) Automatic Demand Shed Controls. HVAC systems with DDC to the Zone level shall be programmed to allow centralized demand shed for non-critical zones as follows:

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The controls shall have a capability to remotely setup the operating cooling temperature set points by 4 degrees or more in all non-critical zones on signal from a centralized contact or software point within an Energy Management Control System (EMCS).

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The controls shall have a capability to remotely setdown the operating heating temperature set points by 4 degrees or more in all non-critical zones on signal from a centralized contact or software point within an EMCS.

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The controls shall have capabilities to remotely reset the temperatures in all non-critical zones to original operating levels on signal from a centralized contact or software point within an EMCS.

4.

The controls shall be programmed to provide an adjustable rate of change for the temperature setup and reset.

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The controls shall have the following features: A. Disabled. Disabled by authorized facility operators; and B. Manual control. Manual control by authorized facility operators to allow adjustment of heating and cooling set points globally from a single point in the EMCS; and C. Automatic Demand Shed Control. Upon receipt of a demand response signal, the spaceconditioning systems shall conduct a centralized demand shed, as specified in 120.2(h)1 and 120.2(h)2, for non-critical zones during the demand response period. 17