4.2 Equipment Requirements

With the exception of chillers as described in Section 4.2.2 below, all of the equipment efficiency requirements are mandatory measures.

The mandatory requirements for mechanical equipment must be included in the system design, whether compliance is shown by the prescriptive or the performance approach. These features have been shown to be cost effective over a wide range of building types and mechanical systems.

It is worth noting that most mandatory features for equipment efficiency are requirements for the manufacturer. It is the responsibility of the designer, however, to specify products in the building design that meet these requirements.  Manufacturers of central air conditioners and heat pumps, room A/C, package terminal A/C, package terminal heat pumps, spot air conditioners, computer room air conditioners, central fan-type furnaces, gas space heaters, boilers, pool heaters and water heaters are regulated through the Title 20 Appliance Efficiency Regulations. Manufacturers must certify to the Energy Commission that their equipment meets or exceeds minimum standards.  The Energy Commission maintains a database which lists the certified equipment and can be found at:

www.energy.ca.gov

Additionally, manufacturers of low leakage air-handling units must certify to the Energy Commission that the air-handler unit meets the specifications in Reference Joint Appendix JA9.

4.2.1    Mechanical equipment subject to the mandatory requirements must:

A.         Be certified by the manufacturer as complying with the efficiency requirements as prescribed in Sections:

§110.1 Mandatory Requirements for Appliances

§110.2 Mandatory Requirements for Space Conditioning Equipment

(a) Efficiency

(d) Gas- and Oil-Fired Furnace Standby Loss Controls

(f) Low Leakage Air-Handling Units

§110.3 Mandatory Requirements for Service Water Heating Systems and Equipment

(a) Certification by Manufactures, and

(b) Efficiency

§110.4 Mandatory Requirements for Pool and Spa Systems and Equipment

(a) Certification by Manufactures

§110.5 Natural Gas Central Furnaces, Cooking Equipment, and Pool and Spa Heaters: Pilot Lights Prohibited

B.         Be specified and installed in accordance with Sections:

§110.2 Mandatory Requirements for Space Conditioning Equipment

(b) Controls for Heat Pumps with Supplementary Electric Resistance Heaters

(c) Thermostats

(e) Open and Closed Circuit Cooling Towers (blowdown control)

§110.3 Mandatory Requirements for Service Water Heating Systems and Equipment

(c) Installation

§120.1 Requirements for Ventilation

§120.2 Required Controls for Space Conditioning Systems including Occupant Controlled Smart Thermostats (OCST)

§120.3 Requirements for Pipe Insulation

§120.4 Requirements for Air Distribution Ducts and Plenums

§120.5 Required Nonresidential Mechanical System Acceptance

4.2.2    Equipment Efficiency      

All space conditioning equipment installed in a nonresidential building subject to these regulations must be certified as meeting certain minimum efficiency and control requirements. These requirements are contained in §110.2 of the Standards.  Minimum efficiencies vary based on the type and capacity of the equipment.  The following Tables, which are based from Tables 110.2A-110.2K of the Standards, list the different minimum efficiencies.

Table 4-1 Efficiencies for unitary air conditioners and condensing units

Table 4-2 Unitary and Applied Heat Pumps

Table 4-3 Air Cooled Gas Engine Heat Pumps

Table 4-4 Water Chilling Packages Minimum Efficiency

(Cont.) Table 4-4 Water Chilling Packages Minimum Efficiency

Table 4-5 Packaged Terminal Air Conditioners and Heat Pumps

(Cont.) Table 4-5 Packaged Terminal Air Conditioners and Heat Pumps

Table 4-6 Heat Transfer Equipment

Table 4-7 Performance Requirements for Heat Rejection Equipment

Table 4-8 Electrically Operated Variable Refrigerant Flow Air Conditioners

Table 4-9 Electrically Operated VRF Air to Air and Applied Heat Pumps

(Cont.) Table 4-9 Electrically Operated VRF Air to Air and Applied Heat Pumps

Table 4-10 Warm-Air Furnaces and Combination Warm-Air Furnaces/Air-Conditioning Units, Warm-Air Duct Furnaces, and Unit Heaters

Table 4-11 Gas and Oil Fired Boilers

In the above tables, where more than one efficiency standard or test method is 'listed, the requirements of both shall apply. For example, unitary air-cooled air conditioners have an EER requirement for full-load operation and an IEER for part-load operation. The air conditioner must have both a rated EER and IEER equal to or higher than that specified in the Standards at the specified Air-Conditioning, Heating, and Refrigeration Institute (AHRI) standard rating conditions   Similarly, where equipment can serve more than one function, such as both heating and cooling, or space heating and water heating, it must comply with the efficiency standards applicable to each function.

Where a requirement is for equipment rated at its “maximum rated capacity” or “minimum rated capacity,” the capacity shall be as provided for and allowed by the controls during steady state operation. For example, a boiler with high/low firing must meet the efficiency requirements when operating at both its maximum capacity and minimum capacity.

Exceptions exist to the 'listed minimum efficiency for specific equipment, the first being water-cooled centrifugal water-chilling packages that are not designed for operation at ANSI/AHRI Standard 550/590 test conditions of 44°F leaving chilled water temperature and 85°F entering condenser water temperature with 3 gallons per minute per ton condenser water flow shall have a minimum maximum full load COP kW/ton and NPLV ratings adjusted using the following equation:

•      Adjusted maximum full-load kW/ton rating = full load (kW/ton) rating from
Table 110.2D/Kadj

•      Adjusted maximum NPLV rating (kW/ton) = IPLV ( kW/ton) rating from
Table 110.2D/Kadj

Where:

Kadj = (A) x ( B)

A = (0.00000014592 x (LIFT)⁴) – (0.0000346496 x (LIFT)³ )+ (0.00314196 x (LIFT)²) – (0.147199 x *(LIFT)) + 3.9302

LIFT  = LvgCond – LvgEvap (°F)

LvgCond = Full-load leaving condenser fluid temperature (°F)

LvgEvap  = Full-load leaving evaporator fluid temperature (°F)

B = (0.0015 x LvgEvap) + 0.934

The adjusted full-load and NPLV values are only applicable for centrifugal chillers meeting all of the following full-load design ranges:

•      Minimum Leaving Evaporator Fluid Temperature: 36°F

•      Maximum Leaving Condenser Fluid Temperature: 115°F

•      LIFT ≥ 20°F and ≤ 80°F

Centrifugal chillers designed to operate outside of these ranges are not covered by this exception and therefore have no minimum efficiency requirements.

The other exception is for positive displacement (air- and water-cooled) chillers with a leaving evaporator fluid temperature higher than 32°F, shall show compliance with Table 4-3 when tested or certified with water at standard rating conditions, per the referenced test procedure.

4.2.3    Equipment not covered by the Appliance Efficiency Regulations is regulated by §110.2 and §110.3.

To comply, equipment specified in the plans and specifications must meet the minimum standards mandated in that section. Manufacturers of equipment not regulated by the Appliance Efficiency Regulations are not required to certify their equipment to the Energy Commission; it is the responsibility of the designer and contractor to specify and install equipment that complies.

To verify certification, use one of the following options:

A.   The Energy Commission’s website includes listings of energy efficient appliances for several appliance types. The website address is www.energy.ca.gov. The Energy Commission’s Hotline staff can provide further assistance 1-800-772-3300 or (916) 654-5106 if not found on the website.

B.   The complete appliance database can be downloaded. This requires spreadsheet programs compatible with Microsoft EXCEL. To use the data, a user must download the database file (or files), download a brand file and a manufacturer file and then decompress the files. Next, the user will need to download a description file that provides details on what is contained in each of the data fields. With these files, and using database software, the data can be sorted and manipulated.

C.   The Air Conditioning, Heating and Refrigeration Institute (AHRI) Directory of Certified Products can be used to verify certification of air-conditioning equipment.  This is available on their website at www.ahrinet.org.

4.2.4    Controls for Heat Pumps with Supplementary Electric Resistance Heaters 

The Standards discourages the use of electric resistance heating when an alternative method of heating is available.  In the case of a heat pump, these systems may contain electric resistance heat strips which act as a supplemental heating source.  If this system is to be used then controls must be put in place that limits the use of the electric resistance to not operate when the heating load can be satisfied with the heat pump alone.  This includes the requirement that the thermostat must be able to provide step up controls that will incrementally adjust the indoor temperature setting so that the heat pump can gradually raise the temperature until the final desired indoor temperature is reached. Also, the controls must set a “cut-on” temperature for compressor heating which is higher than the “cut-on” temperature for electric resistance heating, and the “cut-off temperature for compression heating is higher than the “cut-off” temperature for electric resistance heating. 

Several exceptions exist for this requirement; if the electric resistance heating is for defrost, star-ups and follows the room thermostat set points (or another control mechanism designed to preclude the unnecessary operation) or the heat pump is a room air-conditioner heat pump.

4.2.5    Thermostats

When a central energy management control system is not included in the design of the HVAC system, then a thermostat with setback capabilities must be installed.  This requirement applies to all unitary heating or cooling systems, which includes heat pumps, to have a thermostat that is capable of at least 4 set points in a 24 hour period.  In the case of a heat pump the control requirements of section 4.2.4must also be met.  'In addition, per §120.2(b)4, all unitary single zone, air conditioners, heat pumps, and furnaces, the thermostat must comply with the requirements of Reference Joint Appendix JA5, also known as the Occupant Controlled Smart Thermostats, which are capable of receiving demand response signals in the event of grid congestion and shortages during high electrical demand periods.

There are two exceptions to 120.2(b)4 Occupant Controlled Smart Thermostats:

1.   Systems serving zones that must have constant temperatures to protect a process or product (e.g. a laser laboratory or a museum).

2.   The following HVAC systems do not need to comply with the setback thermostat requirement:

a.   Gravity gas wall heaters,

b.   Gravity floor heaters,

c.   Gravity room heaters,

d.   Non-central electric heaters,

e.   Fireplaces or decorative gas appliance,

f.    Wood stoves,

g.   Room air conditioners,

h.   Room heat pumps

4.2.6    Furnace Standby Loss Controls

Forced air gas- and oil-fired furnaces with input ratings ≥225,000 Btu/h are required to have controls and designs that limit their standby losses:

A.   They must have either an intermittent ignition or interrupted device (IID). Standing pilot lights are not allowed.

B.   They must have either power venting or a flue damper. A vent damper is an acceptable alternative to a flue damper for furnaces where combustion air is drawn from the conditioned space.

Any furnace with an input rating ≥225,000 Btu/h that is not located within the conditioned space must have jacket losses not exceeding 0.75 percent of the input rating. This includes electric furnaces as well as fuel-fired units.

4.2.7    Open and Closed Circuit Cooling Towers

All open and closed circuit cooling towers with rated capacity of 150 tons or greater must have a control system that maximizes the cycles of concentration based on the water quality conditions based on either conductivity or flow.  If the controls system is conductivity based then the system must automate bleed and chemical feed based on conductivity.  The installation criteria for the conductivity controllers must be in accordance with the manufacturer’s specifications in order to maximize accuracy.  If the control system if flow based, then the system must be automated in proportion to metered makeup volume, metered bleed volume, recirculating pump run time or bleed time.

The makeup water line must be equipped with an analog flow meter that is either wired or wireless and an overflow alarm to prevent overflow of the sump in the event of water valve failure.  The alarm system may send an audible signal or an alert through an EMCS (energy management control system). 

Drift eliminators are of a louvered or comb like design that is installed at the top of the cooling tower to capture water particles that become entrained in the air stream.  These drift eliminators are now required to achieve drift reduction to 0.002 percent of the circulated water volume for counter-flow towers and 0.005 percent for cross-flow towers.

Additionally, maximum achievable cycles of concentration must be documented based on local water supply (which is reported annually by the local utility) and Langelier Saturation Index (LSI) of 2.5 or less.  A calculator that is approved by the Energy Commission must be used in this process and the compliance form must be reviewed and approved by the Professional Engineer (P.E.) of record.

4.2.8    Pilot Lights    

Pilot lights are prohibited in:

A.   Fan type central furnaces. This includes all space-conditioning equipment that distributes gas-heated air through duct work §110.5(a). This prohibition does not apply to radiant heaters, unit heaters, boilers or other equipment that does not use a fan to distribute heated air.

B.   Household cooking appliances unless the appliance does not have an electrical connection, and the pilot consumes less than 150 Btu/h §110.5(b).

C.   Pool and spa heaters §110.5(c)(d).

4.2.9    Commercial Boilers

A commercial boiler is a type of boiler with a capacity (rated maximum input) of 300,000 Btu per hour (Btu/h) or more and serving a space heating or water heating load in a commercial building.

1.   Combustion air positive shut-off shall be provided on all newly installed commercial boilers as follows:

A.   All boilers with an input capacity of 2.5 MMBtu/h (2,500,000 Btu/h) and above, in which the boiler is designed to operate with a non-positive vent static pressure.  This is sometimes referred to as natural draft or atmospheric boilers.  Forced draft boilers, which rely on a fan to provide the appropriate amount of air into the combustion chamber, are exempt from this requirement.

B.   All boilers where one stack serves two or more boilers with a total combined input capacity per stack of 2.5 MMBtu/h (2,500,000 Btu/h).  This requirement applies to natural draft and forced draft boilers.

Combustion air positive shut-off is a means of restricting air flow through a boiler combustion chamber during standby periods, used to reduce standby heat loss.  A flue damper and a vent damper are two examples of combustion air positive shut-off devices.

Installed dampers can be interlocked with the gas valve so that the damper closes and inhibits air flow through the heat transfer surfaces when the burner has cycled off, thus reducing standby losses.  Natural draft boilers receive the most benefit from draft dampers because they have less resistance to airflow than forced draft boilers.  Forced draft boilers rely on the driving force of the fan to push the combustion gases through an air path that has relatively higher resistance to flow than in a natural draft boiler.  Positive shut-off on a forced draft boiler is most important on systems with a tall stack height or multiple boiler systems sharing a common stack.

2.   Boiler combustion air fans with motors 10 horsepower or larger shall meet one of the following for newly installed boilers:

A.   The fan motor shall be driven by a variable speed drive, or

B.   The fan motor shall include controls that limit the fan motor demand to no more than 30 percent of the total design wattage at 50 percent of design air volume.

Electricity savings result from run time at part-load conditions.  As the boiler firing rate decreases, the combustion air fan speed can be decreased.

3.   Newly installed boilers with an input capacity of 5 MMBtu/h (5,000,000 Btu/h) and greater shall maintain excess (stack-gas) oxygen concentrations at less than or equal to 5.0 percent by volume on a dry basis over firing rates of 20 percent to 100 percent. Combustion air volume shall be controlled with respect to firing rate or measured flue gas oxygen concentration.  Use of a common gas and combustion air control linkage or jack shaft is prohibited.  Boilers with steady state full-load thermal efficiency 85 percent or higher are exempt from this requirement.

One way to meet this requirement is with parallel position control.  Boilers mix air with fuel (usually natural gas although sometimes diesel or oil) to supply oxygen during combustion.  Stoichiometric combustion is the ideal air/fuel ratio where the mixing proportion is correct, the fuel is completely burned, and the oxygen is entirely consumed.  Boilers operate most efficiently when the combustion air flow rate is slightly higher than the stoichiometric air-fuel ratio.  However, common practice almost always relies on excess air to insure complete combustion, avoid unburned fuel and potential explosion, and prevent soot and smoke in the exhaust.  Excess air has a penalty, which is increased stack heat loss and reduced combustion efficiency.

Parallel positioning controls optimize the combustion excess air to improve the combustion efficiency of the boiler.  It includes individual servo motors allowing the fuel supply valve and the combustion air damper to operate independently of each other.  This system relies on preset fuel mapping (i.e., a pre-programmed combustion curve) to establish proper air damper positions (as a function of the fuel valve position) throughout the full range of burner fire rate.  Developing the combustion curve is a manual process, performed in the field with a flue-gas analyzer in the exhaust stack, determining the air damper positions as a function of the firing rate/fuel valve position.  Depending on type of burner, a more consistent level of excess oxygen can be achieved with parallel position compared to single-point positioning control, since the combustion curve is developed at multiple points (firing rates), typically 10 to 25 points.  Parallel positioning controls allow excess air to remain relatively low throughout a burner’s firing range.  Maintaining low excess air levels at all firing rates provides significant fuel and cost savings while still maintaining a safe margin of excess air to insure complete combustion.