1

2016 Title 24 HVAC Topics

June 4, 2013

2

Introduction CEC 2016 Title 24 Schedule

Jun 2013- Apr 2014

• CEC develop foundation.

• IOUs: research, cost-effectiveness analysis, stakeholder meetings

May-Oct 2014

• Pre-Rulemaking. CEC workshops, First Draft Language

Nov 2014

• IOUs finalize code change proposals for submittal to CEC

• CEC conducts impact analysis report

Jan 2015

• Efficiency committee workshop(s)

• CEC opens Rulemaking for Title 24

Mar 2015

• Efficiency committee hearing(s)

• CEC develops 45-day language

Jun-Sep 2015

• CEC develops 15-day language

• Title 24 CEC Adoption date

Jan 2016

• CBSC Publication date

Jan 1, 2017

• Title 24 Implementation date

3

2016 Residential Measures

All high efficacy lighting

No Ducts in Unconditioned Space:

Walls - R-21 + R5 in hot (all?) CZs

Windows 16% of floor area or high performance windows

QII - Quality Insulation Installation inspection

Tested Infiltration < 3 ACH 50

Heat recovery ventilation

Controlled supply mechanical ventilation

FDD/CID refrigerant charge/condensables

Smart Thermostat and Acc Test

Evap cooling baseline hot/dry CZs

Credit for evaporative FDD

Dual path PV with high efficiency HVAC and DHW

Multi-family prescriptive package

Compact water distribution

Shower/bath heat recovery above 1st floor

Heat pump water heating model

Updated solar thermal model

High efficiency white goods

Whole building (HERS) model including deemed plug loads.

Plug load controller

Reduced water consumption

Plug-in hybrid and EV charging circuit (MF)

ZNE CALGreen Tier

4

RESIDENTIAL HVAC

5

HVAC to Support No Ducts in Unconditioned Space

Eliminate Ducts

• Mini-split as method of getting ducts out of unconditioned space

– Improve VRF model

– Refrigerant leakage/installation training

Ducts and Air Handler in Conditioned Space

• Eliminate atmospheric furnaces

– Sealed combustion furnace

• Can be condensing but don’t have to be

– Combined water heating and space heating

• Water heater in garage but also near hot water loads

– Heat pump (ground source?)

Image Courtesy of

Inquiring Eye Home Inspections, LLC

6

Refrigerant Charge Fault Detection and Diagnostics

FDD/CID refrigerant charge/condensables (2016?)

• Propose a requirement for FDD that would verify proper refrigerant charge, lack of condensables in the system and proper airflow.

– FDD already required for nonres economizers

– Could also be applied to commercial AC

– Addresses problem of winter charge test

– Less times refrigerant system is attached to gauge set with potential for refrigerant loss and contamination of refrigerant (dirt, non-condensables)

7

Evaporative cooling

Evaporative cooling baseline hot/dry CZs

• Evaluate and develop and evaporative cooling code baseline for homes in hot/dry climate zones

• Evaporative options:

– Evaporative condensing

– Evaporative cooling of airstream

• Direct, indirect, direct/indirect

• ACM simulation model:

– based on first principles (wetbulb temperature)

– includes humidity comfort model

8

Avoiding Preemption: Multiple Path Energy Codes

Photovoltaics or Large Impact

Efficiency Measure

Minimum Federal Efficiency Equipment

Other Common Efficiency Measures

Photovoltaics or Large Impact

Efficiency Measure

Minimum Federal Efficiency Equipment

Other Common Efficiency Measures

Prescriptive Paths

Standard Path

Performance

(Software)

Approach

At least one standard path for every alternate

path with higher efficiencies

Reduced or no PV required or

other Eff Measure

Higher Efficiency Equipment than

Fed Min Eff

Other Common Efficiency Measures

Alternate Path

9

Res Ventilation

Controlled supply mechanical ventilation

• Evaluate the costs, the energy benefits and the air quality benefits from replacing exhaust based ventilation with supply based ventilation

Heat recovery ventilation

• Evaluate whether heat recovery ventilators are cost-effective in the more extreme climate zones and develop a proposal if so. This would replace the other mechanical ventilation requirements.

.

10

NONRES HVAC

11

Refrigerant Charge Fault Detection and Diagnostics

FDD/CID refrigerant charge/condensables (2016?)

• Propose a requirement for FDD that would verify proper refrigerant charge, lack of condensables in the system and proper airflow.

– FDD already required for nonres economizers

– Could also be applied to residential AC

– Addresses problem of winter charge test

– Less times refrigerant system is attached to gauge set with potential for refrigerant loss and contamination of refrigerant (dirt, non-condensables)

12

HVAC Design and ACM Measures

Low W/sf HVAC systems

• Limit connected HVAC connected load. Don't double count interlocked loads. Consider a fan efficiency requirement or W/cfm requirement

Heat recovery

• Heat recovery with thresholds by cfm of O/A and climate zone

ACM - Base Case HVAC rule set

• Performance rule set without exceptions (VAV reheat?), max W/sf, validated EPlus algorithms, base case and proposed case when AC not used, comfort model

ACM - Improved and validated VRF simulation

• Rigorous method of incorporating VRF test data into simulation that results in accurate estimate of energy impact.

ACM - VAV w/reheat, integration with DCV, chilled beam and DCV,

• Validate and improve Eplus simulation of nonresidential HVAC simulation types. Compare to eQUEST and rationalize or fix the discrepancies

13

Duct Sealing

Remove current limitations on duct sealing

• (max 5,000 sf) for single zone systems with ducts that are outdoors and in unconditioned that must have ducts sealed, tested and verified spaces

Expand sealing, testing and verifying of return ducts

• Indirectly conditioned spaces (plenums)?

Sealing testing and verifying supply ducts upstream and downstream of VAV boxes

• Outdoors and in unconditioned spaces

• Indirectly conditioned spaces (plenums)?

14

Equipment Efficiency: Dual Path Approach

Dual path prescriptive approach

• Primary path: Minimum Federal equipment efficiency with other measure (PV, window overhangs or internal/external light shelf etc),

– PV desirable as prepares code for ZNE later on

• Alternate path: Higher equipment efficiency than minimum federal levels

– HVAC, Water Heating

Performance model: PV model offsets consumption

• Performance method base case includes minimum federal equipment efficiencies with PV and …

• a method for making trade-offs with other combinations of measures

15

Measures Based on ASHRAE 90.1 Updates

Fans: AMCA 205 Fan Efficiency Grade of xx

• ASHRAE 90.1 is FEG 67

• Curve of motor/fan efficiency that varies with size

Air terminal units: maximum leakage rates

Limit reheating even during economizer mode

16

Advanced HVAC

Advanced HVAC: Nat ventilation, dedicated O/A, + chilled beam or radiant system. Evaporative cooling and desiccant cooling

• Evaluate prescriptive requirements for advanced equipment or ventilation. Remove barriers for performance options for any advanced technology.

Improved Natural Ventilation and displacement ventilation simulation • Evaluate Eplus natural ventilation model and make recommendations for the

ACM. Evaluate the feasibility and cost-effectiveness of a natural ventilation and displacement ventilation base case by climate zone..

Radiant model including comfort • Evaluate Eplus radiant heating/cooling model and make recommendations for

the ACM. Update Eplus model if necessary. Adjust setpoint temperatures based on ASHRAE 55 and operant temperature.

Absorption air conditioning • Suitable to be used with solar heating or heat recovery