Case study: Monks Lake Farm

A large new build detached property off the gas network in Surrey, Monks Lake Farm is one of the first examples of the latest product innovation from Kensa Heat Pumps, the Hybrid ground source heat pump.

Overlooking a large lake at the foot of the property, Monks Lake Farm enjoys not only magnificent views but also a highly efficient heating system thanks to the lake acting as the renewable heat source for the heat pump via a number of pond mats.

Share Button

A large new build detached property off the gas network in Surrey, Monks Lake Farm is one of the first examples of the latest product innovation from Kensa Heat Pumps, the Hybrid ground source heat pump. The Hybrid Twin Compact provides an affordable solution for customers requiring high temperature space heating and hot water with high efficiencies. Blending the efficiency of a standard Twin Compact model with a High Temperature Twin Compact results in efficient space heating and higher water temperatures, without the need for direct electric top-up.

Overlooking a large lake at the foot of the property, Monks Lake Farm enjoys not only magnificent views but also a highly efficient heating system thanks to the lake acting as the renewable heat source for the heat pump.

A number of pond mats were lowered to the bottom of the lake and connect to the property’s Hybrid heat pump, providing a system design that is efficient, cost-effective, and unobtrusive. Feeding the property’s underfloor heating and hot water system, the pond mats deliver a number of advantages:

  • The heat transfer rate from water is higher than that in the ground and the water is in close contact with all of the pipe at all times.
  • The flow/circulation of water provides constant energy replacement.
  • The use of a water source removes the need of digging large trenches reducing the cost of installation.
  • The return temperature to the heat pump is generally 5-6ºC higher increase the COP of the heat pump.

Featuring a 15kW Hybrid ground source heat pump, Monks Lake Farm will benefit from hot water temperatures to 65ºC and space heating to 50ºC. This is achieved by the Hybrid ground source heat pump using a different refrigerant in each of the unit’s compressors. By using the best properties of each refrigerant, the Hybrid removes the need to increase the compressor size of the unit to compensate for any de-rating in heat output associated with pure High Temperature refrigerant, and as a result saves the end user money.

To deliver space heating and hot water the first compressor in Kensa’s Hybrid uses Standard temperature (R407C) refrigerant, whilst the second compressor uses High Temperature (R134a) refrigerant. Both compressors work together to deliver the space heating. When producing hot water, both compressors work together initially, but once the hot water gets hotter than the Standard temperature compressor’s return temperature set point, this compressor turns off. The compressor with the High Temperature refrigerant then takes over on its own to provide an extra 15°C to the hot water cylinder.

Key Facts

  • One of the first examples of Kensa's 15kW Hybrid heat pump
  • Hot water to 65ºC and space heating to 50ºC
  • Pond mats
  • Self build new build
  • Single phase
  • Domestic RHI