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Manor Way Industrial Estate, Manor Way, Woking, Surrey

Crown Estate, Windsor Great Park

The Crown Estate has properties in Windsor Great Park all of which have oil fired central heating systems. In view of their commitment to Sustainable Energy. they wished to trial an air source heat pump (ASHP) installation in one of the properties - High Standing Lodge- which had become due for a total refurbishment. Subject to their experience on this trial, they may proceed with further ASHP installations when appropriate to do so.

The Crown Estate has its own Sustainability Agenda and ASHP’s may become part of their refurbishment programme. Oil fired boilers are one of the most inefficient heating and hot water systems for residential homes, in addition to the carbon emissions level and potential pollution from oil spillage. Replacement with an ASHP can save up to 50% in energy costs. When an oil fired boiler becomes due for replacement in any domestic situation, an ASHP is now recognised as the obvious solution.

High Standing Lodge is an old, solid wall construction, 3 bedroom 2 bathroom property of approx 140 sq.m and is situated on the edge of Windsor Great Park. In June 2009, Heat Pump Installations Limited (HPI) were approached to survey the property and provide a proposal for an ASHP. HPI Ltd are the ONLY Air Conditioning/Heat Pump company which Surrey and Hampshire Trading Standards see fit to recommend to their Surrey consumers in their “Buy With Confidence” scheme (see www, and They have an excellent reputation in the Surrey area which had come to the attention of The Crown Estate Chief Surveyor.

Anthony Afram and his team appraised the property for suitability and concluded that existing low temperature ASHP’s were not suitable given the constraints of the poor insulation profile of the property and the client’s wish to retain a radiator heating solution. HPI had learnt about the launch of a Daikin Atherma HT range, and presented this as one of the best options for this trial installation.

The new Daikin Altherma High Temperature features industry first “cascade” heat pump technology and is able to deliver a water flow temperature of up to 80°C and hot water storage at 70°C . This meant that small radiators could be used with confidence and a low hot water storage volume would meet the requirements.

The Daikin Altherma HT 11 kW unit was selected from the HT range. This system consists of three components.

1. The outdoor unit containing the first of the heat pumps which takes the low grade heat from the surrounding air. The outdoor unit was located near to the house out of sight where the redundant oil storage tank had been.

2. The indoor unit comprises a second compressor system and heat transfer unit which is able to take the upgraded heat from the outdoor unit and to deliver this via a heat exchanger to provide water up to 80°C. The indoor unit was located within the utility room.

3. The Daikin 200 litre hot water cylinder was conveniently mounted on top of the indoor unit. This was the first Daikin Altherma HT installation in the UK and both HPI and Daikin were able to ensure that the installation of the system was successfully completed. Both teams worked well together and the unit was commissioned on the 23rd July 2009. The client team visited the site, saw the unit and was suitable impressed. The first installation provided experience for HPI who are now confident that they will be able to achieve the average 4 day installation times as for Daikin Altherma LT model. The installation has been running well since commissioning with water flow temperatures of 75°C and hot water storage temperatures of 70°C being recorded.

The main benefits of Altherma HT at this property are:

Anthony Afram Managing Director of HPI Ltd said

“This was the first installation in the UK for a DAIKIN Altherma HT. We believe that for similar applications where we see older properties with poor insulation characteristicsand traditional radiator systems the HT model will be the natural selection. There is no other comparable model as yet in the UK and the product will now form the basis of our penetration into the existing homes market. In the UK alone 1.6 m boilers are replaced annually and in many cases (particularly with oil fired or direct electric heating) it is a “no brainer” to switch to an ASHP as the marginal additional costs will be paid back from reduced running costs in only a few years”.

Crown Estate

“The Dakin Altherma HT system could not have come to the market at a better time. We have been struggling to justify ASHP technology with LT output, due to the need to backup the system and boost supplies with electrical heat input in our older properties. The trial of the Daikin Altherma HT system the first of its type in the country was a great opportunity for The Crown Estate to become involved in what we consider to be the way forward as part of our sustainability refurbishment commitment to traditional built housing stock. Both HPI and Daikin Airconditioning UK Ltd. have provided us with the confidence and backup to ensure the smooth installation of the product which required only minor adaptation to the existing heating and hot water pipe work.”