The DATA Specification Text

From Heatweb Wiki
Jump to: navigation, search

The following specification text can be used as guidance when writing a District heating design specification.

DATA

All apartments should be fitted with a Heat Interface Unit (HIU). Each HIU should take its primary heat source from a district heating system, and must be capable of indirectly exchanging heat to the apartment heating system and Domestic Hot Water.

The HIU should be fitted with plate heat exchangers capable of the heating and hot water loads of the property. It should be possible for the heating plate heat exchanger to effectively operate at 3.4kW output at 80 deg C Primary flow & 65-35 deg C across the heating circuit whilst maintaining a turbulent flow on the primary circuit. It should also be possible for both the heating and hot water temperatures to be pre-set on the unit during commissioning, the heating temperature should be settable for radiator or underfloor heating systems, however all temperature controls should be inaccessible to the occupant.

The DHW mode should be activated by a flow turbine at 0.6 l/min, and the HIU should have a primary boost function to accelerate the primary flow to the plate heat exchanger, enabling the HIU to achieve DHW setpoint stability within 60 seconds from cold.

Each HIU should be fitted with an EPP casing to reduce heat loss. The casing should be fitted with tamper-proof security screws to restrict access to internal components. Overall dimensions of the HIU must not exceed 640mm High x 490mm Wide x 271mm Deep.

Each HIU should be fitted with an ultrasonic energy meter. The energy meter should enable wired connection to an M-Bus network but also have 3 pulse inputs to make possible the connection of additional hot and cold water meters and an electricity meter. The energy meter must be accessible to the occupant without the need to remove the HIU casing. The heat meter must also be powered by the M-Bus network with battery back-up should the M-Bus network fail.

Each HIU shall include the following features:-

  • Commissioning settings accessible locally via a laptop or handheld device.
  • Self learning and adjusting to fluctuations in primary system pressure.
  • Option for remote connectivity for data logging, fault finding, and adjustment of operating parameters.
  • Stepper Motor control over both the heating and hot water circuits with full primary closure within 5 seconds of tap closure.
  • DHW Set-point between 45C and 60C.
  • Return temperature limitation.
  • Anti-legionella cycle if there has been no hot water draw-off for 24 hours.
  • Intelligent Domestic Hot Water pre-heat function with the ability to turn the pre-heat off after a defined period of inactivity and the ability to set the pre-heat temperature independently of the DHW temperature.
  • Landlord Security valve fitted within the casing. Valve must be full bore and close on loss of power.
  • Pre-plumbing bracket with isolation valves and flushing bypass.
  • 8 Ltr Heating Expansion Vessel.
  • Optional Secondary return pump on DHW circuit.
  • Optional Low flow Heating plate heat exchanger to achieve 3.5kW Output.
  • Qp1.5 Heat Meter with M-Bus output and 3 Pulse Inputs

Heating Performance

  • Maximum - 25kW - @ 30°C ΔT across Secondary Flow/Return (based on 75°C Primary flow temperature)

Hot Water Performance

  • Minimum - 1 ltr / Min
  • Maximum - 65kW - 20.5 ltr / Min @ 55°C (based on 80°C Primary flow temperature)

DATA PLUS

All apartments should be fitted with a Heat Interface Unit (HIU). Each HIU should take its primary heat source from a district heating system, and must be capable of indirectly exchanging heat to the apartment heating system and Domestic Hot Water.

The HIU should be fitted with plate heat exchangers matched to the heating and hot water loads of the property. It should be possible for the heating plate heat exchanger to effectively operate at 3.4kW output at 80 deg C Primary flow & 65-35 deg C across the heating circuit whilst maintaining a turbulent flow on the primary circuit. It should also be possible for both the heating and hot water temperatures to be pre-set on the unit during commissioning, the heating temperature should be settable for radiator or underfloor heating systems, however all temperature controls should be inaccessible to the occupant.

The DHW mode should be activated by a flow turbine at 0.6 l/min, and the HIU should have a primary boost function to accelerate the primary flow to the plate heat exchanger, enabling the HIU to achieve DHW setpoint stability within 60 seconds from cold.

Each HIU should be fitted with an EPP casing to reduce heat loss. The casing should be fitted with tamper-proof security screws to restrict access to internal components. Overall dimensions of the HIU must not exceed 640mm High x 490mm Wide x 271mm Deep.

Each HIU should be fitted with an ultrasonic energy meter. The energy meter should enable wired connection to an M-Bus network but also have 3 pulse inputs to make possible the connection of additional hot and cold water meters and an electricity meter. The energy meter must be accessible to the occupant without the need to remove the HIU casing. The heat meter must also be powered by the M-Bus network with battery back-up should the M-Bus network fail.

Each HIU shall include the following features:-

  • Commissioning settings accessible locally via a laptop or handheld device.
  • Self learning and adjusting to fluctuations in primary system pressure.
  • Option for remote connectivity for data logging, fault finding, and adjustment of operating parameters.
  • Stepper Motor control over both the heating and hot water circuits with full primary closure within 5 seconds of tap closure.
  • DHW Setpoint between 45C and 60C.
  • Return temperature limitation.
  • Anti-legionella cycle if there has been no hot water draw-off for 24 hours.
  • Intelligent Domestic Hot Water pre-heat function with the ability to turn the pre-heat off after a defined period of inactivity and the ability to set the pre-heat temperature independently of the DHW temperature.
  • Landlord Security valve fitted within the casing. Valve must be full bore and close on loss of power.
  • Pre-plumbing bracket with isolation valves and flushing bypass.
  • 8 Ltr Heating Expansion Vessel.
  • Optional Secondary return pump on DHW circuit.
  • Optional Low flow Heating plate heat exchanger to achieve 3.5kW Output.
  • Qp2.5 Heat Meter with M-Bus output and 3 Pulse Inputs

Heating Performance

  • Maximum - 25kW - @ 30°C ΔT across Secondary Flow/Return (based on 80°C Primary flow temperature)

Hot Water Performance

  • Minimum - 1 ltr / Min
  • Maximum - 75kW - 24 ltr / Min @ 55°C (based on 80°C Primary flow temperature