NIBE S1157 Ground Source Heat Pump Inverter Controlled 9kW, 13kW, 18kW

Description

The NIBE S1157 is an intelligent, inverter-controlled ground-source heat pump designed for both new construction and the modernization of existing heating systems in properties of various sizes. By continuously adjusting the compressor speed to match the building’s current heating demand, the heat pump ensures a consistent indoor temperature while minimizing operating costs year-round. Its well-thought-out design—lacking an integrated hot water tank—results in a remarkably low unit height. This simplifies installation in spaces with limited ceiling height, while allowing hot water capacity to be tailored to the property’s specific needs through the use of an external storage tank or water heater.

Note: Velltra guarantees that all NIBE products marketed and sold by us are manufactured in Sweden and feature top-quality components, specifically adapted for the Nordic market and its demanding climate.

Advanced Inverter Technology and High Energy Efficiency

At the heart of the NIBE S1157 lies a variable-speed inverter compressor, which eliminates the energy-intensive start/stop cycles characteristic of traditional on/off heat pumps. The unit produces exactly the amount of heat and hot water required at any given moment, resulting in an outstanding SCOP (Seasonal Coefficient of Performance) of up to 5.8. This level of efficiency places the unit in the highest possible energy class for space heating, whether operating at a flow temperature of 35 °C or 55 °C. The result is significantly lower heating costs, regardless of whether the system is connected to underfloor heating, low-temperature radiators, or traditional high-temperature heating systems.

Flexibility and Compact Design

With a total height of just 1500 mm, a width of 600 mm, and a depth of 620 mm, the NIBE S1157 offers exceptional installation flexibility. Its compact profile makes it ideal for basements, laundry rooms, or utility rooms with low ceilings—spaces where a combined unit with an integrated water heater might not fit. Since the hot water tank is installed separately—either next to or near the heat pump—you have complete freedom in choosing its capacity. Options range from standard tanks for smaller households to larger storage volumes or integration with solar thermal collectors for properties with high hot water demand.

Intelligent control with NIBE Sense and myUplink

As part of the NIBE S-series, the S1157 is equipped with advanced software and seamless connectivity via NIBE Sense. The system analyzes the building’s heating patterns and incorporates local weather forecasts and current electricity prices—using spot-price optimization—to schedule operation as economically as possible, without compromising comfort. Built-in wireless connectivity allows the heating system to easily connect to myUplink, providing a complete overview and the ability to control the unit remotely via a smartphone or tablet. Furthermore, automated over-the-network software updates ensure that the system is continuously enhanced with new features and refined algorithms throughout its entire service life.

Available output capacities for various property requirements

To ensure optimal sizing, the NIBE S1157 is available in three distinct output capacities: 9 kW, 13 kW, and 18 kW.

• NIBE S1157-9: Well-suited for modern detached homes with normal to medium energy demands.
• NIBE S1157-13: A powerful option for larger detached homes, older properties with higher energy requirements, or smaller multi-family dwellings.
• NIBE S1157-18: Designed for very spacious properties or commercial premises with significant heating loads.

All output versions share the same compact external dimensions and high efficiency, ensuring consistency in sizing and project planning.

Environmental performance and reliable warranty terms

The NIBE S1157 is designed with modern refrigerant circuits that minimize its environmental footprint. With a carbon dioxide equivalent of just 0.011 tonnes for the 9 kW and 13 kW models, and 0.015 tonnes for the 18 kW model, the unit meets very stringent environmental requirements. Please note that the manufacturer’s full warranty is not applicable for units bought in Sweden and installed outside Sweden.

Simple integration and customized installation

Thanks to the unit’s standardized connections and modular design, installation can be carried out efficiently and smoothly. The heat pump can be connected to a variety of heat sources—most commonly geothermal boreholes, but also surface-laid ground loops or lake/water-source collectors, depending on the specific site and soil conditions. The smart display and intuitive user interface simplify commissioning, guiding the installer through the adjustment of heating curves, external sensors, and circulation pumps.

A secure purchase and delivery experience with Velltra Velltra is a pioneer in the field of heat pumps, having delivered thousands of units to satisfied customers across the EU over the years. When you shop with us, your investment is protected every step of the way. All our shipments are fully covered by transport insurance, ensuring a fast and seamless resolution process should any transport damage—however unlikely—occur.

Technical specifications

Common dimensions and specifications for the series

• Width: 600 mm
• Depth: 620 mm
• Height: 1500 mm
• SCOP: Up to 5.8
• Declared tapping profile: XL
• System efficiency class for space heating 35 °C: A+++
• System efficiency class for space heating 55 °C: A+++
• Product efficiency class for space heating 35 °C: A+++
• Product efficiency class for space heating 55 °C: A+++
• Efficiency class for domestic hot water heating: A+

Model-specific data

NIBE S1157-9

• Net weight: 101 kg
• Refrigerant quantity, CO2 equivalent: 0.011 tonnes
• Nominal output: 9 kW

NIBE S1157-13

• Net weight: 101 kg
• Refrigerant quantity, CO2 equivalent: 0.011 tonnes
• Nominal output: 13 kW

NIBE S1157-18

• Net weight: 101 kg
• Refrigerant quantity, CO2 equivalent: 0.015 tonnes
• Nominal output: 18 kW