Honeywell EHIU1 Heat Interface Unit
Product Specification Sheet
Certifications
CE, ACS, RT2012 Titre V
General Description and Application
The HyBo (Hydraulic Interface Unit) is a hydraulic interface installed in multi-family dwellings, connecting centralized systems to individual flats. It combines the efficiency of a centralized boiler with the benefits of individual control and metering. The EHIU1 is a model within the HyBo family.
Main Functions Managed by the EHIU1 Unit:
- Heating: Hydraulic interface between the main rise and the flat, supporting high temperature output, balancing, metering, and on/off control via a room thermostat.
- Domestic Hot Water (DHW): Instantaneous production.
- Domestic Cold Water (DCW): Hydraulic interface between the main rise and the flat, including metering.
The EHIU1 performs best in typical heating systems designed for variable flow characteristics, with high temperature differences (ΔT°) and low return temperatures. High ΔT° conditions minimize nominal water flow, allowing for a more flexible distribution system.
EHIU1 Advantages
- Electronic controller with PID algorithm for safe and comfortable DHW temperature characteristic curves.
- Enhanced safety: no gas or combustion within individual flats; a single centralized boiler offers better control and safety. Instantaneous DHW production enhances hygiene.
- Reduced installation costs: only 3 pipes are needed, potentially using a single rise for both heating and DHW. No ventilation system is required.
- Improved efficiency: pipes and heat exchanger insulation reduce heat losses.
- Minimized flow: allows for smaller pipeline dimensions, reducing costs and simplifying installation.
- Low flow system: reduces pump size and electricity consumption by lowering total system pressure drop.
- Pipeline balancing: low flow systems with low pressure drop pipelines facilitate balancing.
- Low return temperatures: guarantee optimal performance for systems like condensing boilers, district heating, and heat pumps.
- High ΔT°: reduces measurement errors for meters (ref. EN1434, UNI10200).
Hydraulic Scheme
The document includes a hydraulic scheme diagram illustrating the unit's connections and components. The EHIU1 unit includes:
- 1: Manual isolation valve
- 2: Two-way on/off motorized valve
- 4: Blind pipe for energy meter
- 6: Strainer
- 7: Heat meter temperature sensor pocket
- 8: DPCV pressure sensor pocket
- 9: Blind pipe for cold water meter
- 11: Static balancing valve
- 12: Two-way modulating motorized valve
- 13: Heat exchanger
- 14: DHW temperature sensor
- 15: Flow meter
- 16: Manual air vent
- 17: Electronic control
Connections are labeled A through H:
- A: Heating supply from centralized system
- B: Heating supply to apartment
- C: Heating return from apartment
- D: Heating return to centralized system
- E: Domestic Cold Water (DCW) inlet
- F: Domestic Cold Water outlet to apartment
- H: Domestic Hot Water (DHW) outlet to apartment
Working Principles
The unit manages several functions:
- Heating Control: A motorized on/off valve responds to commands from an external thermostat (not included) to open or close the heating circuit.
- Domestic Hot Water (DHW) Production: Instantaneous DHW is produced via a heat exchanger. An electronic system with a PID algorithm and a modulating valve ensures precise temperature control, providing safe, comfortable, and efficient operation, even at low flow rates. When a hot water tap is opened, a flowmeter signals the electronic controller. The controller prioritizes DHW production by diverting all heating fluid to the heat exchanger. Domestic cold water is heated directly. The controller adjusts the modulating valve based on DHW temperature feedback to maintain the set temperature. The system reacts quickly to maintain stable DHW temperatures during flow variations. Optional functions include a warm heat exchanger for faster response and an eco-function to prevent unnecessary DHW activation.
Examples of Working Conditions for DHW Production
The document presents tables detailing working conditions for DHW production with 24-plate and 40-plate heat exchangers, showing parameters like DCW temperature, DHW temperature, flow rates, heating supply/return temperatures, and Delta T (°C) for various scenarios.
Balancing: The unit is equipped with a Honeywell Kombi-3-plus for static balancing. An optional diaphragm can be added for differential pressure automatic balancing.
Metering: The unit is predisposed for 2 heatmeters and 1 watermeter (not included). The first heatmeter measures total energy consumption (heating and DHW), while a second (optional) heatmeter measures heating-only consumption, allowing DHW consumption to be calculated by difference.
Product Codes
| Product Code | Description | Cabinet |
|---|---|---|
| EHIU1-840SIF | EHIU1 with high capacity heat exchanger (40 plates) | no |
| EHIU1-840SIC | EHIU1 with high capacity heat exchanger (40 plates) | yes |
| EHIU1-824SIF | EHIU1 with standard heat exchanger (24 plates) | no |
| EHIU1-824SIC | EHIU1 with standard heat exchanger (24 plates) | yes |
| EHIU1-CAB | Stand-alone cabinet |
Technical Data
Heating circuit to/from flat
- Kind of fluid: Water VDI 2035 (max glycol 30%)
- Max. temperature: 90 °C
- Max. operating pressure: 6 bar
- Max. Flow rate: 1.5 m³/h
- Nominal flow rate: 1.25 m³/h
- Kvs value (m³/h): (A-B)+(C-D): 2.68 (static balancing), 2.18 (automatic balancing)
Heating circuit to/from heat exchanger
- Flow control: Electronic controller with PID algorithm, Motorized modulating valve with equal-percentage regulation disk
- Max. Flow rate for quiet operation: ~1.3 m³/h
- Kvs value (m³/h): (A-D): 1.76 (24 plates); 1.88 (40 plates)
Domestic cold water (DCW) line
- Kind of fluid: Water max hardness 15dGH and pH 7-9
- Max. temperature: 30 °C
- Max operating pressure: 6 bar
- Max. Flow rate: According to meter characteristics
- Nominal flow rate: According to meter characteristics
- Kvs value (m³/h): (E-F): 5.06
Domestic hot water (DHW) line
- DHW production device: Braze welded heat plate exchanger in stainless steel
- Temperature control: Electronic controller with PID algorithm
- Kind of fluid: Water max hardness 15dGH and pH 7-9
- Max. temperature: 60 °C (max set-point)
- Max. operating pressure: 6 bar
- DHW production flow activation: 3.5 l/min (programmable)
- DHW production flow deactivation: 2.5 l/min (programmable)
- Max. flow rate: 22 l/min
- Kvs value (m³/h): (E-H): 1.83
Pipes and connections
- Pipes material and size: Copper, Ø18 x 1 mm
- Connections material and size: Brass - G 3/4"M
Motorized Valve
- Operation time ON/OFF valve: 15 sec
- Operation time Modulating valve: 15 sec
Electrical supply
- Voltage, Frequency: 230 V ±10%, 50 Hz
- Max. power consumption: 10 W
- IP protection (IEC 60529): 20
Supports
- Hydraulic support material: Galvanized sheet 1 mm
- Cabinet/frame and door material: Pickling sheet 1 mm
- Cabinet/frame and door color: RAL 9010
Ambient conditions
- Installation: Indoor
- Ambient temperature range: 5-55 °C
- Humidity range: 25-85% (must not condense)
Other characteristics
- Balancing: Static (dynamic as option)
- Metering: Predisposition for 2 heatmeters and 1 watermeter
- Insulation: Heat exchanger and pipes
- Weight (no fluids inside): 18 kg (24 kg with cabinet)
Installation
The unit is designed for indoor installation with two options:
- Basic frame version (without cabinet): For installation in a dedicated closed technical space.
- Wall hanging (with cabinet): Suitable for retrofitting in old or new buildings.
Installation Indications:
- Install the product on a vertical wall capable of supporting its operating weight.
- All connections should be from the bottom (refer to the hydraulic scheme).
- Install the product in a location protected from frost.
Electrical connections
- Electric supply cables: minimum 3 x 1.5mm²
- Room thermostat: 2 x 0.75mm²
- M-Bus connection: 2 x 0.75mm²
Dimensions
The document includes diagrams illustrating the unit's dimensions. These show the unit's width, height, and depth, with connection points labeled A, D, E, H, F, B, C. One diagram shows the unit with a cabinet, and another shows the basic frame version.
Accessories
The document lists various accessories, including meters (singlejet, ultrasonic, multijet) and M-bus masters, detailing their specifications and compatibility.
Meters and M-bus masters
Optimal combination: Possible alternatives for later installation of remote readout systems require additional parts.
Tables detail specific meter models (e.g., EW1100AC1200, EW7730K1200, EW447M1200) and M-bus masters (e.g., Izar-Center series) with their interfaces (None, Pulse output, RF, M-Bus) and functionalities.
Additional information for a correct design of the system
- Ensure working conditions (flows, temperatures, pressure) align with planned specifications.
- Proper balancing of the hydraulic system is crucial.
- Assume a correct diversity factor for DHW consumption within the building.
- Utilize an electronic variable pump.
- Consider a by-pass at the end of the main rise.
- Minimize distances between the main rise, EHIU1, and DHW terminals where possible.
- Ensure proper piping insulation.
- Heating water quality must comply with VDI 2035 standards.
- Domestic water hardness should be below 15dGH, with a pH between 7-9.
- It is recommended to install units in a protected space outside individual apartments.
Environmental and Combustion Controls
Details for Honeywell GmbH, including address, phone, and fax, are provided. The product is manufactured for and on behalf of Honeywell Technologies Sàrl.
