The Belimo EV075+AKRX-E N4HH is a 2-way 3/4" pressure independent characterized control valve (PI-CCV) with integrated thermal energy metering, rated 11 GPM nominal flow, driven by an electronic fail-safe AKRX-E actuator in a NEMA 4 enclosure with a humidistat-controlled internal heater. It combines a characterized control valve, an ultrasonic flow sensor, supply and return temperature sensors and a communicating actuator in one assembly, so a single device controls flow, measures delivered energy and reports coil performance over BACnet, Modbus or MP-Bus.
Specifications sourced from belimo_EV075_AKRX-E_N4HH_datasheet_en-us.pdf (Belimo exact assembly datasheet, rev 2026-08-19). Verified 2026-08-21.
Common Applications
- Terminal units - fan coils, chilled beams and chilled ceilings, and two-pipe changeover terminals where heating and cooling setpoints are switched over the bus
- Small chilled-water or hot-water coils
- Branch and riser flow verification on small distribution
- Applications requiring measured delivered energy, not just valve position
- Low Delta T remediation, where coil performance must be proven rather than assumed
- Wet, washdown or high-humidity mechanical rooms requiring a NEMA 4 rated enclosure
- Locations where condensation risk is driven by humidity rather than temperature alone
- Circuits that must drive to a defined safe position on power loss
These are documented Belimo Energy Valve application families, not a manufacturer recommendation for this specific model. This valve is an EV4-generation product, on which design flow (V'max) is adjustable across 25-100% of its 11 GPM nominal flow, giving a selectable range of 2.75 to 11.0 GPM. Any application below is suitable only where the required design flow falls inside that range. Source: belimo_ev-4.0-operations_manual_en-us.pdf, Vmax setting, p.37; nominal flow from the exact-model datasheet.
Warranty
Belimo 5-Year Limited Warranty. Coverage is subject to Belimo's applicable Terms and Conditions of Sale and to any product-specific warranty requirements. See Section IX of the Belimo Energy Valve technical documentation for the full terms.
Key Features
Measures delivered energy
An ultrasonic flow sensor plus supply and return temperature sensors compute actual thermal energy through the coil, so the valve reports BTU delivered rather than inferred position.
Pressure independent control
The characterized control valve holds the commanded flow across the stated differential pressure range, so balancing valves and repeat commissioning are not required.
Manages Delta T
Belimo Delta T Manager logic limits flow when the coil is not producing useful temperature difference, addressing Low Delta T Syndrome and reducing pumping energy.
Native BACnet, Modbus and MP-Bus
Communication is integral to the actuator: BACnet/IP, BACnet MS/TP, Modbus TCP, Modbus RTU and MP-Bus are supported directly, with no separate protocol gateway.
Electronic fail-safe positioning
On loss of supply the actuator drives to its configured fail-safe position using stored energy, with no mechanical spring return.
NEMA 4 with humidistat-controlled internal heater
The enclosure carries a NEMA 4 rating and an internal heater, cycled on measured humidity to suppress condensation inside the housing.
Technical Specifications
| Valve Pattern | 2-way |
| Valve Size | 0.75" [20] |
| Nominal Flow (V′nom) | 11 GPM |
| Body Pressure Rating | 360 psi |
| Differential Pressure Range | 5...50 psi / 1...50 psi, see "Flow Reduction Chart" |
| Flow Characteristic | equal percentage or linear |
| Fluid | chilled or hot water, up to 60% glycol max (open loop/steam not allowed) |
| Fluid Temperature | 14...250°F [-10...120°C] |
| Pipe Connection | Internal thread / NPT (female) |
| Flow Measurement Accuracy | ±2% @ 20°C [68°F] |
| Flow Repeatability | ±0.5% (Flow) |
| Flow Sensor Technology | Ultrasonic with glycol and temperature |
| Nominal Voltage | AC/DC 24 V |
| Voltage Range | AC 19.2...28.8 V / DC 21.6...28.8 V |
| Power Consumption (Running) | 35W |
| Transformer Sizing | 44 VA |
| Ethernet Connection | RJ45 socket |
| Power over Ethernet | DC 37...57 V |
| Communicative Control | BACnet/IP, BACnet MS/TP Modbus TCP, Modbus RTU MP-Bus Cloud |
| Control Signal Y | 2...10 V |
| Position Feedback U | 2...10 V |
| Running Time (Motor) | 90 s |
| Running Time Fail-Safe | <35 s |
| Control Accuracy | ±5% |
| Min. Controllable Flow | 1% of V'nom |
| Manual Override | external push button |
| Servicing | maintenance-free |
| Degree of Protection NEMA/UL | NEMA 4 |
| Enclosure | UL Enclosure Type 4 |
| Ambient Temperature | -22...122°F [-30...50°C] |
| Ambient Humidity | Max. 100% RH |
| Storage Temperature | -40...176°F [-40...80°C] |
| Valve Body Material | Nickel-plated brass body |
| Stem | stainless steel |
| Seat | PTFE |
| Characterized Disc | TEFZEL® |
| Ball | stainless steel |
| O-ring | EPDM |
Documentation
Related Products
Frequently Asked Questions
What is the nominal flow rate of the Belimo EV075+AKRX-E N4HH?
The EV075+AKRX-E N4HH is rated 11 GPM nominal flow (V′nom) at a valve size of 3/4".
Does the Belimo EV075+AKRX-E N4HH support BACnet natively?
Yes. BACnet/IP and BACnet MS/TP are integral to the actuator, alongside Modbus TCP, Modbus RTU and MP-Bus. No external protocol gateway is required.
What enclosure rating does the Belimo EV075+AKRX-E N4HH carry?
NEMA 4 / UL Enclosure Type 4. Belimo does not publish an IEC/EN IP rating for this model.
What is the difference between the N4HH and N4HT versions?
The N4HH version cycles its internal heater on relative humidity inside the enclosure. Both carry the same NEMA 4 rating; the difference is what triggers the heater.
Is the Belimo EV075+AKRX-E N4HH fail-safe?
Yes - it uses an electronic fail-safe actuator that drives to a configured position on loss of supply power.
Why might the EV075+AKRX-E N4HH arrive with a gray actuator cover?
Belimo has advised that a supplier issue means some NEMA 4 actuator covers ship in gray rather than orange until further notice. Protective properties and product specifications are unchanged.
Belimo 5-Year Limited Warranty. Coverage is subject to Belimo's applicable Terms and Conditions of Sale and to any product-specific warranty requirements. See Section IX of the Belimo Energy Valve technical documentation for the full terms.
- Type:
- Energy Valve (PI-CCV)
- Valve Pattern:
- 2-Way
- Valve Size:
- 3/4 Inch
- GPM:
- 11
- Actuator Type:
- Fail-Safe
- Actuator Model:
- AKRX-E
- Voltage:
- 24VAC/DC
- Communication:
- BACnet/Modbus/MP-Bus
- NEMA 4/4X:
- Yes
- Enclosure Heater:
- Humidistat
- Connection Type:
- NPT Female
