Kensa Shoebox

Kensa Shoebox is the original compact ground source family that remains alongside the newer Shoebox NX. Current models are the 3 kW S3-P0K and 6 kW S6-P0K, both single phase. They are separate designs with different casing sizes and hydraulic requirements.

Ratings

At B0/W35, Kensa publishes coefficients of performance of 3.54 for the 3 kW model and 3.26 for the 6 kW. Their average-climate SCOP figures at 35°C are 3.68 and 3.46. At the 55°C test application the SCOP values are 2.99 and 2.97.

Both models have a maximum flow temperature of 65°C. Higher flow temperatures reduce efficiency, so this maximum is not the same as a preferred design temperature.

Equipment and size

Both use R134a and a reciprocating compressor. The 3 kW unit measures 515 mm high, 480 mm wide and 360 mm deep and weighs 60 kg. The 6 kW measures 585 by 610 by 595 mm and weighs 100 kg.

Published sound-power ratings are 47 dB(A) and 52 dB(A). The 3 kW model has a 13 A supply rating, while the 6 kW has a 25 A supply rating. Both use Kensa’s starting-current controls, but the circuit design still needs the exact model data.

Installation context

Shoebox can be used with an individual ground array or a shared ambient loop. Each property retains its own heat pump and electricity consumption in a networked arrangement.

There is no built-in backup immersion heater. Domestic hot water uses a separate cylinder and any immersion heater is part of that system. Both models are marked Connect & Notify approved in Kensa’s current table.

Kensa’s post-February 2026 warranty structure applies only where its sale date, registration, installer and other terms are met. Older Shoebox and Shoebox Twin installations may have different documentation.

Related entries

• Kensa
• Shoebox NX
• Ground source heat pumps
• Shared ground-loop systems