Commission Delegated Regulation (EU) No 1254/2014Show full title

ANNEX VIII U.K. Measurements and calculations

1. The specific energy consumption (SEC) is calculated using the following equation: U.K.

where:

• SEC is the specific energy consumption for ventilation per m² heated floor area of a dwelling or building [kWh/m².a];

• t_a is annual operating hours [h/a];

• pef is the primary energy factor for electric power generation and distribution [-];

• q_net is net ventilation rate demand per m² heated floor area [m³/h.m²];

• MISC is an aggregated general typology factor, incorporating factors for ventilation effectiveness, duct leakage and extra infiltration [-];

• CTRL is the ventilation control factor [-];

• x is an exponent that takes into account non-linearity between thermal energy and electricity saving, depending on motor and drive characteristics [-];

• SPI is specific power input [kW/(m³/h)];

• t_h is total hours heating season [h];

• ΔΤ_h is the average difference in indoor (19 °C) and outdoor temperature over a heating season, minus 3 K correction for solar and internal gains [K];

• η_h is the average space heating efficiency [-];

• c_air is the specific heat capacity of air at constant pressure and density [kWh/(m³ K)];

• q_ref is the reference natural ventilation rate per m² heated floor area [m³/h.m²];

• η_t is the thermal efficiency of heat recovery [-];

• Q_defr is the annual heating energy per m² heated floor area [kWh/m².a] for defrosting, based on a variable electric resistance heating.

  ,

  where:

  • t_defr is the duration of the defrosting period, i.e. when the outdoor temperature is below – 4 °C [h/a]; and

  • ΔΤ_defr is the average difference in K between the outdoor temperature and – 4 °C during the defrosting period.

  Q_defr applies only to bidirectional units with recuperative heat exchanger; for unidirectional units or units with regenerative heat exchangers, Q_defr = 0.

SPI and η_t are values derived from tests and calculation methods.

Other parameters and their defaults are given in Table 1. The SEC for label classification is based on the ‘average’ climate.

2. The annual electricity consumption per 100 m² floor area (AEC) (in kWh/a electric per year); and the annual heating saved ((AHS), which means the annual saving in consumption of energy for heating (in kWh fuel gross calorific value per year) are calculated as follows, using the definitions in point 1, and the default values given in Table 1, for each type of climate (average, warm and cold): U.K.

;

.

Table 1

SEC calculation parameters

a Defrosting applies only to bidirectional units with recuperative heat exchanger and is calculated as Qdefr = tdefr*Δtdefr*cair*qnet*pef. For unidirectional units or units with regenerative heat exchangers, Qdefr = 0
general typology					MISC
Ducted ventilation units					1,1
Non-ducted ventilation units					1,21
ventilation control					CTRL
Manual control (no DCV)					1
Clock control (no DCV)					0,95
Central demand control					0,85
Local demand control					0,65
motor & drive					x-value
on/off & single speed					1
2-speed					1,2
3-speed					1,5
variable speed					2
Climate	th in h	ΔΤh in K	tdefr in h	ΔΤdefr in K	Qdefr ain kWh/a.m2
Cold	6 552	14,5	1 003	5,2	5,82
Average	5 112	9,5	168	2,4	0,45
Warm	4 392	5	—	—	—
Defaults					value
specific heat capacity of air, cair in kWh/(m3K)					0,000344
net ventilation requirement per m2 heated floor area, qnet in m3/h.m2					1,3
reference natural ventilation rate per m2 heated floor area, qref in m3/h.m2					2,2
annual operating hours, ta in h					8 760
primary energy factor electric power generation & distribution, pef					2,5
space heating efficiency, ηh					75 %