Under Floor heating design and installation with a heat pump or boiler

One of the most important factors when designing a heating system is to understand the integration of the heat source be it a ground\air source heat pump or gas\oil boiler and the effects flow temperatures have on performance, efficiency and comfort. This is even more important when using under floor heating due to the slow reaction time, meaning any action you take today (raise room temperature) takes effect tomorrow. We provide a complete design and installation service for all types of under floor applications.

Our standard solid floor design is based on a screeded floor construction with the underfloor heating pipes clipped to floor grade insulation and embedded within the screed layer. With a standard sand/cement based screed the thickness of screed should comply with the requirements of BS 8204, which specify a minimum screed thickness of 75mm except for domestic and light loading applications where a thickness of 65mm is acceptable. Alternatively a liquid flow screed can be used with a minimum thickness of 50mm.

Where under floor heating is required in suspended timber floors there a number are number of different methods to consider; metal diffuser plates, over lay systems and pipe clipped to insulation between the joists.

Due to the different construction methods we offer a free technical design service for all types of under floor heating to make sure the right system is applied every time.

Uponor under floor heating design, 16mm 20mm PEX pipe, manifolds, diffuser plates, supsended and soild floor

What type of ground collector do I need for a ground source heat pump?

Solutions ground source slide 9

Ground source heat pumps can extract energy from the ground or water using a closed loop or open loop collector. The size of the array is dependent on a number of factors including but not limited to the peak heating and cooling loads and usage of the building.

The most common design is to use a horizontal collector buried in a trench 1.2m deep x 1m wide. This method does require a large amount of ground and can not be used to build on. A typical 3 bedroom house would require 300-400m of pipe.

If space is an issue then a vertical borehole can be drilled. The bore hole is drilled to depths of up to 150m for residential properties. One of the most important factors with drilling is to ensure a thermal grout is pumped in to remove air from around the bore hole pipe. A lot of companies do not do grout and rely on the water table which will vary throughout the year. This will cause inefficiencies in the heat pump and potential system failure.

Ground source heat pump design and installation open trench slip trench

The slip trench design uses a 200mm wide bucket to install a single collector pipe. Trenches must be a minimum of 1m apart.

 The open trench design uses a 1m wide bucket to install the collector pipe either side of the trench. Trenches must be a minimum of 1m apart.

Clivet Ground Source Heat Pump for Hayle Renewable Business Park

Hayle Marine - Clivet XENN Ground Source Heat Pump - Heating - 8 x 100m Bore holes - SD SoultionsAs a specialist in commercial ground source heat pumps we were asked to provide a turnkey package for the design and installation of a system capable of supplying heating and cooling to this flag ship renewable energy centre in Hayle, Cornwall.

Using our expertise in designing heat pump systems that provide heating and cooling we are able to store rejected energy from the cooling cycle within the bore hole array which is then harvested during the heating operation. A total of 8 x 100m bore holes were drilled in the car park and distributed from a sealed manifold chamber.

Not only does this increase the performance and efficiency of the heat pump but also reduces the capital cost due to fewer bore holes being required.

From our extensive commercial range we selected 2No Clivet XENN Ground Source Heat Pumps working in cascade to provide increased part load efficiency. A BacNet building management interface provides remote access to the 80kW heating\cooling system.

The heat pump supplies a 800L buffer tank providing space heating at 45˚C and cooling at 7˚C to the Uponor under floor system.

The building is in the process of claiming the Non Domestic RHI tariff which will provide a revenue for the next 20 years.