F1355

NIBE F1355 is a current high-output inverter-driven ground-source heat-pump family. NIBE’s UK page lists F1355-28 and F1355-43. The inverter-driven compressors vary heat production with demand, but the model designation is not a guarantee of output at every design condition.

Output and cascade use

Selection should use the capacity and electrical-input tables for the exact suffix at the proposed source and heating-water temperatures. The building heat loss, hot-water demand and operating strategy determine whether one unit or a cascade is appropriate.

NIBE says an F1355 can be installed with up to nine other NIBE heat pumps, giving a published maximum of ten units in a cascade. A cascade needs designed staging, hydraulic flow, controls and electrical supply. Adding nominal model numbers does not establish available system output at the coldest source condition.

System arrangement

F1355 is an indoor brine-to-water heat pump without an integrated domestic hot-water cylinder. It requires a designed ground, borehole or suitable water-source circuit, heating distribution and the necessary circulation, expansion, safety and electrical equipment. Domestic hot water needs an external cylinder and associated controls where required.

NIBE gives the family an A+++ heating energy label and identifies myUplink monitoring and control. The label is based on standardised product tests, while online data shows operation rather than proving the ground-array or heating-system design. Seasonal performance also depends on source temperature, brine pumping, flow temperature and hot-water use.

Ground-side and heating design

System sizing uses room-by-room heat loss, design flow temperature, emitter output and hot-water assumptions. The ground array is defined by the assumed geology or water condition, borehole or collector arrangement, extraction rate, antifreeze, flow and pump duty.

A cascade adds the exact models, lead-lag sequence, low-load behaviour, hydraulic arrangement, combined electrical demand and resilience strategy to that calculation. Cooling, pool, solar or supplementary-heat integration also needs compatible accessories and its own control logic.

Warranty eligibility depends on registration, installer route, servicing and the complete NIBE UK terms.

Related entries

• NIBE
• NIBE F1345
• Ground source heat pumps
• Heat-pump sizing