Generation

The generator provides the heating or cooling of the distribution network which then will transport the heat or cold to the emissive device of the air handling unit. The emissive devices can be specified as a list using the HVAC template.

Visualisation

It is possible to visualise the generation system using a particular colour. This colour will be used in the 3D visualisation in the results section. In case you assign conspicuous colours to the various templates, this will give you a quick overview of the different templates used in the project.

Configuration

configuration

For the heat loss and EPG calculation, a distinction is made between individual and collective systems. For heat loss, this distinction is made to determine the design capacities for buildings with individual and/or collective installations in a building complex.

For EPG, this distinction is made for the standard efficiencies of heating boilers and the determination of auxiliary energy for heating. For domestic hot water, systems with circulation pipes and hot water storage tanks, as well as systems with block heating where heat is transferred to domestic hot water via a heat exchanger, are considered collective systems

Calculation method Auxiliary energy

In case of individual systems, both the flat rate and detailed method can be chosen to calculation the auxiliary energy for heating.

• Flat rate: The auxiliary energy for individual systems is determined using the flat rate method.
• Detailed: The auxiliary energy for individual systems is determined according to quality statements. A sub-screen ‘Auxiliary energy heating’ appears for the generators in which the auxiliary energy can be specified in multiple ways.

Generators

To specify the generator system a choice can be made among a heat generator, a cold generator, and a domestic hot water generator. A combi-heat generator can be specified for heating and domestic hot water.

Generator (preferent)

“For the generator within the ‘System’, it can be indicated whether it is preferred. This is only relevant if multiple generators are specified for Heat, Domestic Hot Water, or Cold; if a single generator is specified, it is automatically preferred. If multiple generators are specified for Heat, Domestic Hot Water, or Cold, but no preferred generator is specified, the rules in NEN 7120 dictate that a preferred generator will be chosen. If a preferred generator is specified and the rules are exceeded, the EPG calculation will issue a notification.”

Type

Location of the generator

The location of the generator can be indicated here. This location is only taken into account for individual boilers for which the efficiency is determined flat rate. The location does not make a difference for all other generators. The option ‘Inside zone’ indicates the generator is ‘located within the boundaries of the EPG calculation’. For the other options the calculations are performed with the generator ‘placed outside the boundary of the EPG calculation’.

• Inside zone generator is placed INSIDE the boundary of the EPC calculation.
• Inside building and outside zone generator is placed OUTSIDE the boundary of the EPC calculation
• Against building generator is placed OUTSIDE the boundary of the EPC calculation
• Inside parcel generator is placed OUTSIDE the boundary of the EPC calculation
• Outside parcel generator is placed OUTSIDE the boundary of the EPC calculation

Type

The type of the generator can be selected from a presented list of options.  This list is generated depending on the configuration of the generation (individual or collective) and the selected system (heat, cold, domestic hot water, or combi). An overview of the generator for different configurations and systems is presented below:

Heat generator (individual and collective systems)

Cold generator (individual and collective systems)

Domestic hot water generator (individual systems)

Domestic hot water generator (collective systems)

Combi heat generator (individual systems)

Combi heat generator (collective systems)

 

Heat system

Heat certificate

For a boiler used for heating and/or domestic hot water, you can indicate the type of boiler here. Depending on the choice, this determines both the standard and part-load efficiency (see tables 14.11 and 19.19 of NEN 7120). For high-efficiency (HR) boilers, the return temperature of the distribution network is also important for the part-load efficiency.

Heat certificate

 

Generator with pilot

For a Conventional Efficiency Boiler and an Improved Efficiency Boiler used for heating, it can be indicated whether there is a pilot light present. Additional thermal auxiliary energy use is accounted for in this case (see section 14.6.5 of NEN 7120).

Modulating power control

A power control can be specified here in the case of a generator for heating. The power control effects charging the auxiliary energy use of the generator.

Lower modulation

If modulating power control has been applied, then the lower level of modulation can be specified in the range from 0.4 – 1.0. In case the specified limit is below 0.4, then the standard of 0.4 is assumed.

Energy

In case of a Conventional Efficiency Boiler for heating, it should be specified whether this boiler is fired by gas or oil. This choice can be made only if the heat certificate is ‘Conventional efficiency’.

• Gas gas-fired boiler
• Oil oil-fired boiler

Cold generator

Energy carrier

In case of a compression chiller (cold generator) it should be specified whether it concerns a compression chiller driven by a gas engine or by electricity.

• Gas engine gas engine driven compression chiller (or heat pump)
• Electricity electrically driven compression chiller (or heat pump)

Source

Specification of the source of the compression chiller. This impacts the input of the Building Simulation Efficiency.

Specifications

The specifications of a compression chiller (cold generator) are specified from this selection list. The flat rate efficiency is determined based on these specifications. Additionally, the auxiliary energy use to dispose the cooling power of the cold generation is determined using these specifications. The specification ‘high temperature delivery system’ is not included in the selection list as this is passed on to the cooling system in the resource ‘Distribution’.

• Not specified
• Dry cooler
• Evaporation condenser
• Wet cooling tower
• Low temperature cold source

Compressor

Specification of the compressor details. This choice can only be made if the type is set to compression chiller and the building simulation efficiency is set to part-load efficiency.

Closed circuit

In case of a compression chiller or absorption chiller, this box indicates whether the wet cooling tower or evaporation condenser is a closed circuit. This property is taken into account to determine the auxiliary energy required to dispose the cooling power.

Pump(s) / ventilator(s) with speed control

This box indicates that the pumps of the cooling water circuit between the cooling machine and cooling source, or the ventilators of the air-cooled condensers or cooling towers, have speed control. This property affects the determination of auxiliary energy required for the generation of the cooling system.

Custom thermal conversion factor

For the gas-driven compression chiller you may deviate from the flat rate thermal conversion factor by manually specifying its value.

Publications

 

Shaft power

The shaft power of the engine of the gas-driven compression chiller should be specified in order to determine the thermal power of the cold generator.

Water flow

In case cold storage is applied as cold generator, the flow of groundwater or the flow through the soil heat exchangers should be specified to determine the thermal cooling power.

Domestic hot water system

Certificate domestic hot water

The certificate for domestic hot water should be specified for the (combi) boiler or hot water system in order to determine the flat rate efficiency of the (combi) boiler.

• No: no certificate applicable;
• CW: certificate comfort water is applicable;
• HRww: certificate high efficiency hot water is applicable.

Application class

The Gaskeur-CW-comfort class (Dutch) certificate should be specified for a (combi) boiler or hot water system. This certificate is applied to determine the flat rate efficiency of the (combi) boiler.

• Comfort class 1 ‘sink’ for kitchen use only.
• Comfort class 1* is equivalent to Comfort class 1 with the addition night shower tapping of Comfort class 2 of 3.5 dm³/min
• Comfort class 2 certificate high efficiency is applicable
• Comfort class 3 domestic hot water flow of at least 6 dm³/min at 60º, and filling a bath tub with 100 dm³ water at 40º within 12 min.
• Comfort class 4 domestic hot water flow of at least 7.5 dm³/min at 60º, and filling a bath tub with 120 dm³ water at 40º within 11 min.
• Comfort class 5 domestic hot water flow of at least 7.5 dm³/min at 60º, and filling a bath tub with 150 dm³ water at 40º within 10 min.
• Comfort class 6 domestic hot water flow of at least 7.5 dm³/min at 60º, and filling a bath tub with 200 dm³ water at 40º within 10 min.

Publications

 

Biomass

For (combi-)boiler or heat pump it needs to have a quality mark to determine the flat rate of the kettle (zie tabel 19.16 NEN 7120).

• Biomass for boilers according to Activity Decree
• Biomass for boilers according to minimum burning quality in Annex O
• Biomass other

Publications

 

Power

The properties of the heat generator are specified here. The power of the heat generator is determined by the specified power of the air ventilation units in the various rooms which are calculated, and the part which is required for the heating coil in the air handling unit. The total power is doubled to ensure sufficient power is available to provide for the air ventilation units and the heating coil. The input and output temperature are important to determine the flow.

Thermal power

The maximum thermal power of the generator can be specified here, expressed in kW. In case ‘Unlimited’ is specified no excess hours will develop based on a limited power of the generator. If excess hours do develop in this case, another component has to be specified.

• Unlimited: it is assumed the generator has an unlimited power
• Cosum value: The maximum power produced by the generator should be specified. If the required power is higher that this delivered power, the design temperature may not be reached. In this case one should increase the power or use a secondary generator.

Rated power vs Thermal vs Shaft power

 

Efficiency Building Simulation

This option is available when a specific value is entered for the thermal power. The efficiency is used in the Energy & Cost module to calculate energy consumption.

• Part-load efficiency: efficiency is determined hourly, depending on the type of generator. You can read more about part-load models in this article.
• Yearly averaged efficiency: a fixed (annual average) efficiency is used for calculations.

Supply temperature

Supply temperature of the heat pump in °C.

Nominal source temperature

Nominal temperature of the source associated with thermal power, nominal supply temperature, and nominal efficiency. Input is necessary for part-load efficiency in the case of Heat Pump, Compression Chiller, and Absorption Chiller types.

Nominal supply temperature

Nominal supply temperature of the distribution network associated with thermal power, nominal source temperature, and nominal efficiency. Input is necessary for part-load efficiency in the case of Heat Pump, Compression Chiller, and Absorption Chiller types.

If the supply temperature generated by the generator and the source temperature are the specified values, then the generator produces the specified power. If the specified supply temperature of the distribution network or the source temperature is different, then the power is rescaled.

Reference source temperature

Annual average reference temperature of the source. Input is necessary for part-load efficiency in the case of Heat Pump, Compression Chiller, and Absorption Chiller types. This source temperature is used throughout the year. If the source is outdoor air, it does not need to be filled in because it is derived from the climate data file.

Nominal efficiency

Nominal efficiency associated with nominal source temperature, nominal supply temperature, and reference source temperature. Input is necessary for part-load efficiency in the case of Heat Pump, Compression Chiller, and Absorption Chiller types.

Costum conversion efficiency

If deviating from the default efficiency, this can be indicated here. For a heating heat pump, this is the COP value, and for a cooling heat pump (specified as compression chiller), this is the EER value. A quality statement must accompany the deviating efficiency.

Conversion efficiency

Specification of the efficiency (or COP, EER) of the generator if a deviating efficiency (quality statement) is provided.

Efficiency domestic hot water

Specification of the efficiency of domestic hot water in case of a combined generator (Heating & Domestic Hot Water) if a deviating efficiency (quality statement) is provided.

Heat pump

Watch the webinar here

COP meets minimum value

If a heat pump for heating is specified where the efficiency (COP value) must be determined by default, you can indicate here whether the COP value meets the conditions as indicated in table 14.14 NEN 7120. The minimum COP value is only used for electric heat pumps for residential buildings where the efficiency (COP) is determined by default; see table 14.13 NEN 7120.

If a heat pump boiler for domestic hot water is specified where the efficiency (COP value) must be determined by default, you can indicate here whether the heat pump meets the generation efficiency of at least 2.2 as per Annex A (see table 19.16).

Publications

 

Type

Specification of the type of heat pump

Combined heat pump

If the applied heat pump is a combined heat pump, this is indicated here.

Source

Specification of the heat pump source. This affects the input for Building Simulation Efficiency.

Specification of the heat pump source. For the EPG (Energy Performance of Buildings) calculation, this is only applicable if the efficiency needs to be determined by default; see tables 14.13 and 14.16 NEN 7120. In Building Simulation, the source only affects calculations when part-load efficiency is considered.

Publications

 

Air-to-water heat pump

When specifying a heat pump, you can indicate here whether the heat pump is of the air-to-water type. For an air-to-water heat pump, both the energy fraction and efficiency must be provided according to a quality statement as per Annex E NEN 7120. The energy fraction is only applicable if multiple generators are specified for heating.

The option for air-to-water heat pump appears only if “Outdoor air” or “Return air” is specified as the source (residential or utility).

Publications

 

Energy fraction

Specification of the energy fraction if an air-to-water heat pump is specified. The energy fraction is the share of the total heat or cold supply provided by a heat or cold generator. In the case of only one generation device, the value of the energy fraction is 1. For an air-to-water heat pump with non-integrated auxiliary heating, the share is determined from the heat supplied by the heat pump.

Publications

 

Minimum air flow rate

For a heat pump water heater, a minimum air volume flow rate may be required to operate properly. If this is known according to the manufacturer’s specifications, it can be indicated here, and the minimum flow rate can be specified in dm3/s. If no minimum air volume flow rate is provided, it will be determined based on the floor area of the building or part of the building.

Publications

 

Source

It affects when part-load efficiency is considered.

DHW energy fraction

When choosing a booster heat pump with the heat source specified as the heating system and building cooling, please fill in the energy fraction for domestic hot water.

Cogeneration

Electrical power

Specification of the electrical power of the (micro)CHP. This power is used according to the default method to determine the thermal and electrical conversion factors of the (micro)CHP according to table 14.17 NEN 7120. The conversion factors indicate what portion of the supplied energy is converted into heat and what portion into electricity.

Publications

 

Custom conversion efficiency

Deviation from the default values of the conversion factors for heat and electricity can be specified here by providing different conversion factors. Quality statements must be provided to support these deviations.

Thermal

Specification of the thermal conversion factor of the (micro)CHP as specified by the manufacturer if a different conversion factor (quality statement) is provided.

Electric

Specification of the electrical conversion factor of the (micro)CHP as specified by the manufacturer if a different conversion factor (quality statement) is provided.

Auxiliary energy for heating

Calculation method Auxiliary energy

The auxiliary energy of an individual device can be specified in two detailed ways:

• Annual auxiliary energy: in MJ; if the annual auxiliary energy is provided in the quality statement of a device, it can be specified here.
• According to Annex C: the auxiliary energy consumption of a device is determined according to Annex C of NEN 7120, where a number of constants and the nominal values according to the quality statement are specified.

Publications

 

Auxiliary energy

Specification of annual auxiliary energy in MJ according to the device’s quality statement.

Constant A - C and nominal B

Constant A

Device constants for calculating auxiliary energy according to the device’s quality declaration (see Annex C NEN 7120).

Constant B

Device constants for calculating auxiliary energy according to the device’s quality declaration (see Annex C NEN 7120).

Constant C

Device constants for calculating auxiliary energy according to the device’s quality declaration (see Annex C NEN 7120).

Nominal B

The nominal load of the device in kW higher heating value according to the device’s quality declaration (see Annex C NEN 7120).

Solar boiler

Solar collector

At the solar collector, you have to choose which solar collector is used in the system. The entry of solar collectors must take place through Tools and Solar Collector (heat).

Depending on how the solar collector is used (Heat, Hot water, or Heat & Hot water), the input screen will be adjusted to the data for the different systems.

Calculation Method

Calculation method for determining the solar contribution of solar energy systems for domestic hot water. This method can only be specified if a solar boiler (domestic hot water) is indicated with a collector area greater than 6 m2 and less than or equal to 10 m2. For solar boilers (domestic hot water) with a collector area of 6 m2 or less, calculation method a is used by default. For solar boilers (domestic hot water) with a collector area greater than 10 m2, or for solar energy systems (heating) or solar combination systems (heating and domestic hot water), calculation method b is used by default (see section 19.6.3 NEN 7120).

Simple (method a): The solar contribution of the solar boiler to domestic hot water is determined according to section 19.6.3 NEN 7120.
Comprehensive (method b): The solar contribution of the solar boiler to domestic hot water is determined according to Annex I NEN 7120.

Publications

 

Type

Type of solar water heater as used for a domestic hot water system. The type of solar water heater can only be specified if the solar water heater is used solely for domestic hot water, and the system is configured for “Tapwater.”

1. Pre-heater solar water heater with secondary heating appliance: The solar water heater acts as a pre-heater with a storage tank for storing the heated water, which is then further heated by a boiler (combination boiler) during use. In the generation configuration, alongside the solar water heater, a boiler (combination boiler) must be specified as a heat source.

2. Integrated gas-fired auxiliary heater: The solar water heater is heated via a heat exchanger in the storage tank by a boiler (combination boiler). Hot water is tapped directly from the storage tank. In the generation configuration, alongside the solar water heater, a boiler (combination boiler) must be specified as a heat source.

3. Integrated electric auxiliary heater: The solar water heater includes an integrated electric heating element in the storage tank. Hot water is tapped directly from the storage tank. For domestic hot water, no additional heat source is required in the generation configuration.

Publications

 

Mode of operation for supplementary heating

Specification of the control type of the supplementary heating of the solar energy system. The control type is used to determine a correction factor for the capacity of the storage tank of the solar energy system and is only used for calculation method b when a solar energy system with integrated electric supplementary heating is chosen. See table I.5 NEN 7120 for details.

Publications

 

Zonnekeur

If the solar energy system meets the conditions required for the Zonnekeur label, this can be indicated here. This affects the default determination of the annual solar contribution under calculation method a (see tables 19.10 and 19.11 NEN 7120) and the default determination of the efficiency, heat loss coefficient, and angle dependency coefficient of the solar collector under calculation method b (see tables I.2 and I.3 NEN 7120).

Publications

 

Annual Solar Contribution

The annual solar contribution used in calculation method a can be determined either based on standard values from tables 19.10 and 19.11 of NEN 7120 or can be specified in detail. A quality statement must be provided for detailed specification.

Standard: The annual solar contribution is determined according to tables 19.10 and 19.11 of NEN 7120.
Detailed: The annual solar contribution is specified as ‘Energy output at solar energy exit’ in MJ/year. This value is derived from a quality statement and must be provided for the calculation.

Insulated pipes

For determining the losses of the pipes in the collector circuit, you can indicate here whether the pipes are insulated or not. The input regarding the pipe insulation is only applicable for calculation method b. See table I.4 NEN 7120.

Auxiliary energy

Calculation method

The auxiliary energy of a solar energy system can be determined either by default or in detail. For the detailed method, a quality declaration must be provided.

• Default: The auxiliary energy is determined according to Section 19.8.4 NEN 7120.
• Detailed: The auxiliary energy is input based on a quality declaration, which must be added to the calculation.

Publications

Collector pump present

For the collector pump and the collector pump control, auxiliary energy will be charged if a collector pump is present. This can be indicated here.

Calculation values

When specifying the presence of a collector pump and the flat-rate calculation method for determining auxiliary energy, you can indicate here whether the calculation values of the collector pump should be determined flat-rate or based on self-disclosure.

Flat-rate: The power of the collector pump is determined flat-rate according to par. 19.8.4.3 NEN 7120;
Self-disclosure: The power of the collector pump and the collector pump control is known and can be specified here in watts.

Publications

Power collector pump

The power of the collector pump should be specified here, expressed in W. This parameter can only be stated if the calculation method is flat rate, a collector pump is available, and the design values are specified as custom values.

Power collector pump control

The power of the collector pump control should be specified here, expressed in W. This parameter can only be stated if the calculation method is flat rate, a collector pump is available, and the design values are specified as custom values.

Auxiliary energy collector pump and control

The annual auxiliary energy for the collector pump and the collector pump control can be specified here according to a quality statement, expressed in MJ / year. This auxiliary energy can only be specified if the calculation method is detailed and a collector pump is available.

Frost protection available

Auxiliary power will be charged if frost protection is available, which can be indicated here.

Power frost protection

The power of the frost protection system should be specified here, expressed in W. This parameter can only be stated if the calculation method is flat rate and frost protection is available.

Auxiliary energy frost protection

The annual auxiliary energy for the frost protection can be specified here according to a quality statement, expressed in MJ / year. This auxiliary energy can only be specified if the calculation method is detailed and frost protection is available.

Storage tank (domestic hot water)

Own input heat transfer

The heat transfer coefficient of the heat storage is determined flat rate by default, but may also be specified in detail by presenting an own heat transfer coefficient in W/K. This coefficient is used to determine the heat loss and heat storage. The heat transfer coefficient is only asked for if the calculation method is performed in detail and according to method B.

Location

The location of the storage tank is important as it is used to determine the heat loss.

• Outside
  The heat loss of the storage tank is determined with the outside air as ambient temperature.
• Unheated space
  The heat loss of the storage tank is determined with an ambient temperature in between the heated space and the outside air.
• Heated space
  The heat loss of the storage tank is determined with an ambient temperature equal to the heated space.

Volume

The total volume of the storage tank of the solar energy system is specified here, expressed in dm³. The volume is used to determine the reduction factor for the yield of solar energy in PVT-systems, and to determine the correction factor for the efficiency of heat storage in systems with integrated reheating.

Hot water storage tank

For biomass device for domestic hot water, the insulation of the hot water storage tank must be specified:

• Uninsulated
• Minimum thickness of 10 mm
• Minimum thickness of 20 mm

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