Water-Source Heat for NT's Packwood House

Midlands based Lorien Engineering Solutions has helped a flagship National Trust property drive down its yearly operating costs by some £23,000 with the installation of a water source heat pump.

The pioneering system, installed at Packwood House in Warwickshire, is one of the first installed at a National Trust property and was completed over the winter with 5,000 metres of pipe submerged in the lake in a series of coils. The heat pump works by circulating a food safe glycol fluid within the pipes, which absorbs solar energy held in the water.

The team of sustainability engineers at Burton based Lorien designed and managed the installation, and they estimate that it will save Packwood House £23,000 per year that is currently spent on oil. The project took 90 days to complete and was financed by a £192,500 grant from energy provider npower.

Lorien’s Stuart Perry explained how the system works: “The high efficient vapour circulates cool glycol through the vast pipe array submerged in the lake where the low grade heat from the water is naturally absorbed and thus raises its temperature.

“The fluid is then passed through a compressor unit which increases the temperature considerable enough to change the liquid into vapour, the vapour then passes back through a condenser section where the temperature is lowered again and the vapour changes back to a liquid. This is where the useful latent heat is captured, stored and subsequently used to heat the property.

“This constant cycle is virtually silent and although the process requires an electrical demand to run, will produce up to four times as much energy as it needs to run.”

A 250 metre  trench was dug to connect the pipes to the new heat pump units by the house, replacing existing oil-fired boilers.

Packwood’s house manager Joy Tovey said: “The water source heat pump is a really great addition to the property. It provides us with a constant source of steady heating which for older types of our properties such as Packwood House, are essential. Over time it will save us a lot of money, allowing us to invest in essential property maintenance and the conservation of our chattels for us and future generations to enjoy.”

The property will also receive around £6,000 each year from the government’s renewable heat incentive programme.

Lorien and the National Trust: Over the past 5 years, Lorien have worked on in excess of 80 projects with the National Trust with a focus on renewable energy systems (heat pumps, biomass, solar and hydro-electric) to Mansion Properties and their wider Estates.  Lorien further specialise in the provision of environmental control, delivering re-servicing, conservation heating and overall building management to both modern and listed buildings.

Heat recovery units (above)

Trenching to Manor House (below)