Title 24 Report Glossary

Glossary of Terms for a Title 24 Report

Title 24 Report incorporate these energy terms listed below. These terms will help you understand some of the acronyms and words that appear on the Title 24 Report.

Acceptance Requirements
Test procedures that include equipment and systems to be tested, functions to be tested, conditions under which the test shall be performed, the scope of the tests, results to be obtained, and measurable criteria for acceptable performance. (California)

An addition is the extension or increase in the conditioned floor area and volume of a building. This includes converting an existing unconditioned space to a conditioned space, such as remodeling a basement, garage or attic. The standards require energy compliance analysis and documentation for all additions that increase the conditioned space and volume of the building.
AFUE (Annual Fuel Utilization Efficiency)
The ratio of annual output energy to annual input energy, which includes any non-heating pilot input loss and, for gas- or oil-fired furnaces or boilers, does not include electric energy.

Airflow Across the Evaporator
The efficiency of air conditioners and heat pumps is affected by the airflow across the evaporator (or condenser in the case of a heat pump). Measuring the temperature split or temperature drop across the evaporator and comparing this measurement to reference tables can verify proper airflow. See also Thermostatic Expansion Valves (TXV).

An alteration is any change to a building’s water heating system, space conditioning system, lighting system, or envelope that is not an addition.

Alternative Calculation Method (ACM)- Title 24 Report
An alternative calculation method is one of the Commission’s Public Domain Computer Programs or any other calculation method approved by the Commission. (California)

Alternative Component Packages
An alternative component package is one of the sets of prescriptive requirements contained in the standards. Each package is a set of measures that achieve a level of performance, which meets the standards. These are often referred to as the prescriptive packages or packages. Buildings that comply with the prescriptive standards shall be designed, constructed and equipped to meet all of the requirements of one of the alternative packages of components for the appropriate climate zone. (California)

Automatic Time Switch
An automatic time switch is a device capable of automatically turning loads off and on based on time schedules.

Btu/hr (Btu/h)
British thermal unit per hour, also abbreviated Btu/h. One Btu equals the amount of heat needed to raise the temperature of one pound of water one degree Fahrenheit. Used for measuring heating and cooling equipment output.

Building Envelope
The building envelope is made up of the elements of a building that enclose conditioned spaces and through which thermal energy may be transferred to or from the exterior.

Climate Zone- Title 24 report
The Energy Commission established 16 climate zones that represent a geographic area for which an energy budget is established. These energy budgets are the basis for the Title 24 energy standards. (California)

Coefficient of Performance, Cooling (COP)
The coefficient of performance for cooling is the ratio of the rate of net heat removal to the rate of total energy input, calculated under designated operating conditions and expressed in consistent units.

Coefficient of Performance, Heating (COP)
The coefficient of performance for heating is the ratio of the rate of net heat output to the rate of total energy input, calculated under designated operating conditions and expressed in consistent units.

Combined Hydronic Space/Water Heating
A combined hydronic space conditioning and water heating system is one in which both domestic hot water and space heating is supplied from the same water heating equipment. Combined hydronic space heating includes both radiant floor systems and convective or fan coil systems.

Conditioned Floor Area (CFA)
Conditioned floor area is the total floor area (in square feet) of enclosed conditioned space on all floors of a building, as measured at the floor level of the exterior surfaces of exterior walls enclosing the conditioned space.

Conditioned Footprint Area
The conditioned footprint is the total area of the building footprint, in square feet, not including unconditioned space. The conditioned footprint area may be equal to the first floor area, or it may be greater. The footprint area is the total area of floor over unconditioned space (not over conditioned space), ambient air and slab-on-grade. One way to think of the conditioned footprint area is as the area of the largest conditioned floor in the building plus the conditioned floor area of any projections from other stories that extend beyond the outline of that largest floor.

Conditioned Space
In residential compliance, conditioned space is space in a building that is either directly conditioned or indirectly conditioned.

Controlled Ventilation Crawl Space (CVC)
The Energy Commission has approved an exceptional method for analyzing the energy impact of buildings with raised floors which use foundation wall insulation and have automatically controlled crawl space vents. The method is available as an option using an approved computer method with unique modeling criteria. (California)

Cooling Load
The rate at which heat must be extracted from a space to maintain a desired room condition.

Cool Roof
A cool roof is a roof surface with a high reflectivity and high emittance. A cool roof rejects solar heat before it enters the building by reflecting it back to the atmosphere.

Crawl Space Title 24 report
A crawl space is a space immediately under the first floor of a building adjacent to grade. The thermal characteristics of a crawl space (or any similar vented unheated space below a raised floor) tend to reduce heat loss and heat gain into the building compared with an open, unprotected space below the floor. Compliance credit for the crawl space is assumed to be equivalent to an additional R-6 insulation value. R-6 insulation is not modeled when a raised floor is over an open area or over a garage. (California)

Daylight Area
The floor area under skylights or next to windows. The daylight area includes primary sidelit daylight area, secondary sidelit daylight area, and skylit daylight area.

Daylighting Control, Automatic Multi-level;
A multi-level lighting control that automatically reduces lighting in multiple steps or continuous dimming in response to available daylight. This control uses one or more photosensors to detect changes in daylight illumination and then change the electric lighting level in response to the daylight changes.

Decorative Gas Appliance
A decorative gas appliance is a gas appliance that is designed or installed for visual effect only, cannot burn solid wood, and simulates a fire in a fireplace. A decorative gas appliance installed in a new residential building or addition cannot contain a continuously burning pilot light, and cannot use indoor air for cooling a firebox jacket if the indoor air is vented to the outside of the building. (California)

Demand Response
Controlling electricity loads in buildings in response to an electronic signal sent by the local utility requesting their customers to reduce electricity consumption.

Demising Partition
A demising partition is a wall, fenestration, floor, or ceiling that separates conditioned space from enclosed unconditioned space.

Design Heat Gain
The design heat gain is the total calculated heat gain through the building envelope under design conditions.

Design Heat Loss
The design heat loss is the total calculated heat loss through the building envelope under design conditions.

Dimming, Continuous
A lighting control method that is capable of varying the light output of lamps over a continuous range from full light output to minimum light output.

Dimming, Stepped
A lighting control method that varies the light output of lamps in one or more pre-determined discrete steps between full light output and off.

Directly Conditioned Space
Directly conditioned space is an enclosed space that is provided with wood heating, is provided with mechanical heating that has a capacity exceeding 10 Btu/(hr

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