4.1    Overview

4.1.1                                                                                                                   Introduction and Organization    

This chapter addresses the requirements for heating, ventilating, and air- conditioning (HVAC) systems. The requirements are presented in this chapter to serve as a source of information for mechanical system designers and mechanical system installers, as well as energy consultants, HERS Raters and enforcement personnel.

Each section in this chapter outlines the mandatory measures and when applicable, the prescriptive requirements or compliance options.  These prescriptive requirements vary by climate zone.  If the building design does not achieve the minimum prescriptive requirements, then the compliance options may be used under the performance approach to achieve compliance.

The chapter is organized under the following sections:

1.    Heating Equipment.  This section addresses the requirements for heating equipment, including mandatory metopic=(b)topicasures, prescriptive requirements, and compliance options.

2.    Cooling Equipment. This section addresses cooling equipment requirements, including mandatory measures, prescriptive requirements, and compliance options.

3.    Air Distribution System Ducts, Plenums. This section covers mandatory requirements such as duct insulation, duct system construction practices and duct diagnostic testing.  This section also covers prescriptive requirements for duct location and duct insulation, and specifications for access holes in the supply and return plenums.

4.    Controls. This section addresses mandatory requirements for thermostats and the compliance option for zonal controls.

5.    Indoor Air Quality and Mechanical Ventilation. This section covers mandatory requirements for indoor air quality including mechanical ventilation.

6.    Alternative Systems. This section covers several systems that are less common in California homes, including hydronic heating, radiant floor systems, evaporative cooling, gas cooling, ground-source heat pumps, and wood space heating.

7.    Compliance and Enforcement. In this section the documentation requirements at each phase of the project are highlighted.

8.    Refrigerant Charge. This section addresses the requirements for refrigerant charge verification including procedures prescriptive requirements and compliance option.

9.    Chapter 9 covers the heating and cooling requirements for additions to existing dwellings and for alterations to existing heating and cooling systems.

4.1.2                                                                                                                   What’s New for the 2016 Standards

The following is a summary of the new HVAC measures for the 2016 Building Energy Efficiency Standards (Energy Standards) including new compliance options that provide greater flexibility in complying with the Energy Standards when using the performance method.  See sections of this 'manual for more detail.   Mandatory Features and Devices - Section 150.0

1.          Liquid line filter driers are required to be installed on all air-conditiong condensers, as specified by the manufacturer (§150.0(h)3).

2.          There are some changes to the tables specifying mandatory minimum insulation on air-conditioning refrigerant lines (§150.0(j)2C).

3.          There are some changes to the mandatory insulation protection for insulated pipes found outside conditioned space (§150.0(j)3).

4.          The term directly conditioned space was replaced with conditioned space to capture ducts located in indirectly conditioned spaces. The mandatory minimum R-value for duct located in conditioned spaces is now R-4.2 (§150.0(m)1).

5.          Duct sealing and leakage testing for single-family dwellings and townhouses has a new target for total duct leakage, which has been reduced to 5 percent total leakage(§150.0(m)11).

6.          There are new mandatory requirements for filtration of all air passing through a ducted space-conditioning system.  The requirements affect the pressure drop and labeling of the filtration devices (§150.0(m)12C).   Prescriptive and Performance Compliance Approaches - Section150.1

1.          The refrigerant charge requirement was restructured to clearly state that minimum system airflow is required in conjunction with refrigerant charge verification (§150.1(c)7).

2.          The exception to 150.1(c)7 for packaged systems was amended to allow the installer to certify that they installed a packaged system that was charged by the manufacturer (§150.1(c)7).

3.          New requirements for duct insulation and duct system location depending on the location of ceiling or roof insulation were added. (§150.1(c)9).

4.          The prescriptive requirements for ventilation cooling have been changed. The total airflow requirement was reduced from 2 CFM/ft2 to 1.5 and the vent-free area was reduced from 1 ft2/375 CFM to 1 ft2/750 CFM (§150.1(c)12).   Additions and Alterations - Section 150.2

The Energy Standards requirements for HVAC systems in homes that are altered or added to are summarized and discussed in Chapter 9.

4.1.3                                                                                                                   Common System Types    

New California homes in the Central Valley and the desert typically have a gas furnace and split -system air conditioner that distributes heating and cooling to each room through forced air ducts. Most mandatory measures and prescriptive requirements are based on this type of system.  In some areas, a heat pump provides both heating and cooling, eliminating the furnace. In coastal climates and in the mountains, air conditioning is rare and most new homes are heated by gas furnaces.

Although the Energy Standards focus on the typical system, they also apply to other systems as well, including some radiant hydronic systems. These hydronic systems distribute hot water to parts of the home to provide heating to the conditioned spaces.

Electric resistance systems are used in some areas and applications, although it is difficult for them to comply under the Standards.

Ground-source or water source heat pump (geo-exchange) systems are also used, especially in areas where there is no gas service.  Unlike more typical air source systems, these systems use water circulated underground or in large ponds or lakes as the heat source (in heating mode) and heat sink (in cooling mode).

While the primary focus of this chapter is typical systems, a Section 4.7 discusses alternative systems.

4.1.4                                                                                                                   California Appliance Standards and Equipment Certification    

Most heating and cooling equipment installed in new California homes is regulated by the National Appliance Efficiency Conservation Act (NAECA) and/or the California Appliance Efficiency Regulations (Title 20). Both the federal and state appliance standards apply to the manufacturing of new equipment and are applicable for equipment used in replacements, repairs,  or for any other purpose. The Appliance Efficiency Regulations are enforced at the point of sale,  (except central split system air conditioners and central single package air conditioners, see Table 4-6), while the Energy Standards explained in this compliance 'manual are enforced by local enforcement agencies.

The following types of equipment (in the list below) are covered by the Appliance Efficiency Regulations. For this equipment, the manufacturer must certify that the equipment complies with the current Appliance Efficiency Regulations at the time of manufacture.

Appliances covered by the Appliance Efficiency Regulations include:

1.     Room air conditioners

2.     Room air-conditioning heat pumps

1.     Central air conditioners with a cooling capacity of less than 135,000 British thermal units per hour (Btu/hr)

3.     Btu/hr

4.     Central air conditioning heat pumps

5.     Gas-fired central furnaces

6.     Gas-fired boilers

7.     Gas-fired furnaces

8.     Gas-fired floor furnaces

9.     Gas-fired room heaters

10.   Gas-fired duct furnaces

11.   Gas-fired unit heaters

The Appliance Efficiency Regulations do not require certification for:

1.    Electric resistance space heaters

2.    Oil-fired wall furnaces, floor furnaces, and room heaters (Some are voluntarily listed with certified gas-fired furnaces).

Equipment that does not meet the federal appliance efficiency standards may not be sold in California. Any equipment covered by the Appliance Efficiency Regulations and sold in California must have the date of manufacture permanently displayed in an accessible place on that equipment. This date is frequently included as part of the serial number.

Note: Equipment manufactured before the effective date of a new standard may be sold and installed in California indefinitely, as long as the performance and prescriptive approach demonstrates energy compliance of the building using the lower efficiency of the relevant appliances However, the Department of Energy (DOE) requires that central split-system air conditioners and central single package air conditioners installed in California on or after January 1, 2015 must comply with the minimum efficiencies as specified in Table 4-6.

The compliance and enforcement processes should ensure that all installed HVAC equipment regulated by the Appliance Efficiency Regulations is certified to the California Energy Commission. Plan Review Process (Compliance)

During the plan review process the builder is responsible for demonstrating compliance with the Appliance Efficiency Regulations by providing the efficiency of the HVAC equipment that is to be installed. Typically the builder does not identify the exact make or model at this point of the process. The plans examiner is responsible for verifying that the specified equipment efficiency complies with the Appliance Efficiency Regulations.      Field Inspection (Enforcement)

It is the responsibility of the field inspector to visually verify that the product information on the installed HVAC equipment matches the efficiency that was approved by the plans examiner. To simplify the inspection , the field inspector may reference the CF2R-MCH-01-H form submitted by the builder/installing contractor. Moreover, the field inspector is responsible for verifying that the installed HVAC equipment is certified to the Energy Commission. The field inspector, at his or her discretion, may require the builder/installing contractor to provide a printout from the Energy Commission Appliance Efficiency Database of certified equipment listing the same make and model that is installed.

If the specifications labeled on the HVAC equipment do not match the equipment specifications on the Energy Commission Appliance Efficiency Database, the inspector is responsible for issuing a correction notice to the builder/installing contractor.