Title 24 HVAC

The 2013 Title 24 Residential Compliance Manual has laid out the HVAC requirements and standards that construction projects must comply with. These Title 24 HVAC requirements ensure that both new structures and renovations of older buildings have a mandatory “greener” use of energy. Chapter 4 of the Residential Compliance Manual addresses the requirements for heating, ventilating, and air conditioning (HVAC) systems and can serve as a single source of building HVAC requirement and information for Title 24 energy consultants, mechanical engineers and mechanical contractors.

Items covered in the HVAC chapter of Residential Title 24 manual are as follows:

1. Heating Equipment. This section addresses the requirements for heating equipment, including mandatory measures, 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 specifications for access holes in the supply and return plenums to accommodate pressure and temperature measurements by installers and HERS raters.

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 a number of 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. More information on the refrigerant charge verification procedures is included in this section.

The following information has been taken from the CEC 2013 Residential Compliance Manual (http://www.energy.ca.gov/2013publications/CEC-400-2013-001/CEC-400-2013-001-CMF-REV.pdf )

Summary of the new HVAC measures for 2013

The following is a summary of the new hvac measures for the 2013 standards, including new compliance options that provide greater flexibility in complying with the standards when using the performance method. See individual sections of this manual for more detail. Mandatory features and devices – section 150.0

1. The indoor design temperature for heating load calculations has been changed from 70 degrees to 68 degrees. [150.0(h)2]

2. Air conditioning condensers are required to be located at least 5 feet from a clothes dryer vent outlet. [150.0(h)3]

3. Gas furnaces must be designed and installed to meet the manufacturer’s maximum temperature split in heating mode. [150.0(h)4]

4. There are some changes to the tables specifying mandatory minimum insulation on air conditioning refrigerant lines. [150.0(j)2c]

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

6. There is a new reference to a mandatory duct construction standard, ansi/smacna-006-2006 hvac duct construction standard. [150.0(m)1]

7. The mandatory minimum duct insulation r-value has been raised from r-4.2 to r-6, except for ducts located completely within directly conditioned space. [150.0(m)1]

8. Duct sealing and field verification is now a mandatory measure (moved from the prescriptive packages) and can no longer be traded off by using the performance approach. [150.0(m)11]

9. There are some changes to the target leakage rates for dwellings in multifamily buildings. [150.0(m)11]

10. There are new mandatory requirements for filtration of all air passing through a ducted space conditioning system. the requirements affect the design, efficiency, pressure drop and labeling of the filtration devices. [150.0(m)12]

11. There are new mandatory requirements to ensure proper duct and filter grill sizing for forced air distribution systems that supply cooling to an occupiable space. they include requirements for a hole for a static pressure probe (hspp) and an option to either size return ducts based on prescriptive tables or field testing to meet airflow and fan watt requirements. [150.0(m)13]

12. There are some new mandatory requirements for space cooling systems that utilize automatic zonal control to meet airflow and fan watt draw requirements. [150.0(m)15]

13. The mandatory whole building ventilation requirement of ASHRAE 62.2 is now a HERS verified measure. [150.0(o)]