Quick Finder
Contact Us
Call us now for EXPERT advice...
0845 680 2183
Ask An Expert

The Whole House Approach for New Builds: 

The three main energy requirements of a property are:

  1. Electricity
  2. Heating
  3. Water

This document runs you through the products and their costs (both supply and installation). A summary of the products used and their associated costs are as follows:

 

   

System   Cost

Installation   & Commissioning

Solar PV

 

Standard 4kWp

£3,747.58

£2,498.39

 

Roof Integrated Slate system

£6,018.31

£4,012.20

 

 

   

ASHP

 

DHW

£2,437.60

£780.00

 

Central Heating

£6,485.00

£2,450.00

 

UFH System (whole house)

£5,719.65

£3,900.00

 

 

   

GSHP

 

Horizontal Looping

£8,738.52

£7,854.25

 

Vertical Looping / Bore Hole

£8,738.52

£14,963.25

 

 

   

MVHR

£3,398.72

£1,170.00

 

 

   

Rainwater Harvesting

£3,287.50

£1,850.00

 

 

   

Grey Water System

NA

£850.00

 

 

   

Waste Water Heat Recovery

£890.00

£245.00

 

All prices are indicative and dependant on a site survey. These prices have been based on a new build property. 

1.Electricity:

For electricity we use standard Solar PV systems that turn daylight into electricity. There are two main systems that you can choose from:

Standard Solar PV Modules:

These are standard modules that measure (approximately) 1.6 square meters and are connected in series to form an array.

Roof Integrated Modules:

Both systems qualify for the UK Governments Feed in Tariff (FiT) system. However, to obtain the maximum tariff rate the system should not be over 4kWp. A 4kWp system in the South of the UK will produce around 3,633kWh of electricity. This is how much energy is required to run a 4 bedroom house. However, due to natural living habits, and the fact that PV does not produce electricity at night and cannot store the electricity it produces, the house will export electricity to the grid during the day and import electricity at night times (and in winter). However, with the Feed in tariff system the net annual electricity bill should be a cash flow to the client[1].

The cost and financials of each system are as follows:

System

On Roof

In Roof

Total System Power

4 kWp

3.995   kWp

System Cost (Vat Excl)

£6,245.97

£10,030.51

Annual FiT Payment & Elec Bill   Savings

£808.59

£807.58

Total FiT Payment over 20 years

£20,352.66

£20,327.21

Annual Return

12.95%

8.05%

Payback Period (Years)

7.72

12.42

 

Heating:

There are two heating requirements of a property:

  1. Central Heating (C/H)
  2. Domestic Hot Water (DHW)

For the heating system we split the Central Heating from the Domestic Hot Water and use a separate Heat Pump for either system. The reason why we suggest splitting the C/H and DHW into separate systems is to give you the greatest efficiency and lowest cost running, whilst maintaining the highest safety standards. The principle points underlying our design philosophy are:

  1. All standard heat pumps are designed to run within an operating temperature spread of 30 – 45 degrees Celsius system temperature. If you go above this, the efficiency level falls away quickly, meaning that you give back the efficiency you have gained on the Central Heating side whenever you need domestic hot water (DHW) delivered (at 55 – 60 degrees Celsius). Thus, with our configuration, the heat pump is never overstretching itself.
  2. If using only one unit for both Central Heating and Domestic Hot Water, in summer you will be starting and running a large compressor just to maintain the availability of DHW. This is very inefficient and high cost compared to running the Energie system.
  3. In winter, a single unit will only be able to give you either Central Heating or Domestic Hot Water warming at any one time. So either the DHW runs colder or the C/H does not get the required attention.
  4. In winter, the single ASHP will be running much harder than it should be when producing the 55 Degrees Celsius DHW – this is a costly exercise and will shorten the life span of the ASHP.
  5. A standard ASHP will not provide a pasteurisation cycle for the DHW system – the Ecocent does, once a week and it is critical to maintaining the quality of domestic water.
  6. To deliver DHW, a standard ASHP needs to be a minimum of 3kW larger than when delivering heat for space heating alone – so has the single ASHP trying to perform both functions has higher overall capital cost.

For the C/H heating system we recommend that you use an [ESP 15 kW] Classic Unit for the Central Heating (sited outside the house) and, for domestic hot water (DHW), we suggest the use of the ESP 300ltr Ecocent unit (a very stylish unit that many of our clients actually use to make a ‘feature’ for the house).

 

ASHP Units: Central Heating: [ESP 15kW ASHP]

The Central Heating ASHP’s are all built using the “best in class” components, including best in class safety devices – Wilo water pumps, Danfoss Heat Exchangers, Oak Industries evaporators, Hitachi/Sanyo compressors, etc. This means that they are robust and that spares will be available over the unit life span. The cabinets are stainless steel to ensure that the units remain clean and tidy throughout their life span; even the screws are stainless steel.

The Central Heating ASHP is fitted with the water pump and flow switch inside. You will need to put a buffer tank between the ASHP unit and the heat distribution system and we would suggest using a 200 ltr tank. The buffer tank will mean fewer, but longer, heating cycles because it will give the heating system adequate water content to export heat from the ASHP to the point of delivery at the same time as providing a heat store – this is the best and most economic way to run a heat pump because most power is used by a heat pump when starting up the compressor.

The buffer tank will be equipped with a [3]kW immersion heater that will be for manual operation as the heating “final resort” in exceptional circumstances. We keep this “last resort” back up as a manually operated facility so that a conscious decision must be made to use the extra heating capacity and because we do not envisage that you will need to employ the facility frequently.

In relation to start up current, the [15]kW unit is unique in that it has two smaller compressors (rather than one [15]kW compressor) that start up in series and never together. Along with the soft starts, this means that they have a very low start up current requirement. We also offer a controls upgrade that will deliver exceptional efficiency. The upgraded controls will cause the compressors to switch on and off individually and to individually modulate output in a coordinated way to ensure that the lowest input power is called upon to deliver the amount of heat required by the house. This means that, in cold weather, you have the capacity of [15] kW to call upon and, on warmer days, the unit will operate with a much lower output (and hence power draw). The upgrade also gives the ASHP the ability to learn over time what the most cost effective way to heat your house in all ambient conditions.

The [15]kW Classic ASHP is MCS accredited, making it potentially eligible for payments under the Renewable Heat Incentive (RHI) Scheme that is due to start next year (eligibility backdated to cover units installed after July 2009)[2].

The cost of the ESP [15]kW Classic is as follows:

 

System   Cost

Installation   & Commissioning

Central Heating

£6,485.00

£2,450.00

  

ASHP Units: Domestic Hot Water: ESP Ecocent 300ltr

 The Ecocent unit is a combined DHW cylinder with a fully integrated heat pump (680W). It generates hot water by extracting heat from air ducted to it.

Ducting for installation of the Ecocent will form part of the MVHR system so that the Ecocent forms an integrated part of the whole house mechanical ventilation and heat recovery (MVHR) system. The air intake for the Ecocent will be from the MVHR ductwork sources and this air will be diverted to the Ecocent automatically (by the Ecobox diverter) upon the Ecocent starting up to replenish the DHW temperature. At the same time, the Ecocent will communicate with the MVHR heat exchanger and cause it to pause so that the two elements of the system are not competing for the same air. Once the Ecocent has replenished the DHW temperature, the process will reverse. When the air passes through the Ecocent, the heat will be extracted and will be transferred to the water stored in the integral cylinder and cold air will be expelled, unless used for cooling – the cold air could be put to good use in the summer for cooling, in a larder, wine storage area, conservatory, etc. The use of the cold air can be facilitated by a second Ecobox diverter that is automatic or manually switched over for the summer – however, separate ducting to handle this cooling facility would need to be installed to focus the cold air delivery to the chosen areas within the house.

The Ecocent is available with 2 secondary coils that enable you to introduce secondary heat sources (although not needed) or to take heat from the unit for other purposes (e.g. towel rails). You get all the flexibility of a hot water cylinder, but with the low running costs of the integrated ASHP.

The Ecocent unit is very efficient (a COP of over 4.0 across the heating curve, up to 55 Degrees Celsius), low cost to run and designed and built to the highest safety standards. It can be run as a vented or unvented system and is supplied with a magnesium anode fitted as standard (to protect the stainless steel cylinder) as well as having a second coil in the cylinder that can be used to incorporate a secondary source of heat if you wish (either now or in the future). A mandatory safety feature of the Ecocent is that it will automatically go through a pasteurisation cycle once a week to prevent the growth of legionella.

The unit is exceptional value given that you will not have to purchase a separate hot water cylinder and given the very low running cost and reduction is system capital cost as noted below – by comparison with solar thermal panels, the Ecocent is lower cost to buy and install (by quite some margin) and the Ecocent will provide you with 100% of your hot water requirements all year round (whereas a solar thermal system will provide a maximum of 50% of the annual requirement).

Standing heat loss from the integrated cylinder is minimal and you can save up to 70% on your DHW costs annually – this will not be the case if you use a single ASHP unit for both C/H and DHW duties. The Ecocent will also mean that you can reduce the size of the space heating unit, thus lower the cost of equipment on that side of the system. With the smaller ASHP required, the Ecocent is reducing the overall cost of the heating system by an amount that more than covers the TOTAL COST of the Ecocent – effectively achieving 100% payback before it is switched on.

The fact that the ASHP’s require electricity to run the Solar PV system is installed to generate the electricity required by the heat pumps.

 The cost of the Ecocent DHW unit is as follows:

 

 

System   Cost

Installation   & Commissioning

DHW

£2,437.60

£780.00

 Under Floor Heating (UFH):

 Heat pumps work best with Under Floor Heating systems, and the cost of an UFH system for both the ground floor and first floor fully installed is as follows:

 

System Cost

Installation & Commissioning

UFH System (whole house)

£5,719.65

£3,900.00

 

The system includes screeding the downstairs floor and using aluminium spreader plates on the first floor. The pipes are guaranteed for 50 years and all manifolds, thermostats and zoning is included in the above cost.

 

Ground Source Heat Pumps:

 Another variation of heat pumps is a Ground Source Heat Pump. This is where the heat is extracted from the ground. There are two main types of system, and to give a comparative quote I show prices for each using a 15kWp heat pump:

 

   

System   Cost

Installation   & Commissioning

GSHP

 

Horizontal Looping

£8,738.52

£7,854.25

 

Vertical Looping / Bore Hole

£8,738.52

£14,963.25

 

 The system is for full installation and uses a Vaillant Ground Source Heat Pump.

 Mechanical Ventilation and Heat recovery (MVHR):

 Whilst we profess to say that the number one rule about renewable energy is insulation; insulation and more insulation, it is also true that all buildings must have ventilation systems so that old, stale air (that can become dangerous to your health) is removed and replaced with new, fresh air. This is especially true in areas where there is a lot of condensation such as in the kitchen or in bathrooms as this ventilation will avoid problems with damp. Passive houses also need these systems as they are essentially “sealed” houses.

Traditionally ventilation systems revolve around extractor fans and air vents on window frames. Mechanical Ventilation Heat Recovery (MVHR) systems take out the old air, which has already been warmed to the desired temperature of the building occupier, and uses this old hot air to warm the new, fresh air as it comes into the building. The two airs never mix, and thus the new fresh air can be distributed into the building already heated, thereby requiring less heating from the buildings traditional heating system. 

MVHR systems can capture and re-use up to 90% of heating lost through ventilation systems. We use Rega Ventilation systems in our developments. As noted above, the Ecocent unit can be fully integrated in to the MVHR system and this will ensure maximum efficiency across the systems as well as providing for very effective ventilation and heat recovery.

The costs of the MVHR system are as follows:

   

System   Cost

Installation   & Commissioning

MVHR

£3,398.72

£1,170.00

 

Rainwater Harvesting:

We supply and install a Direct RWH System from Freerain. Direct systems are easy to install and provides a pressurised clean water supply to your toilets for flushing; washing machines and dishwashers for cleaning; and garden taps for watering etc as the are connected directly to the Mains supply.

The rainwater is collected through the drainpipe system and goes through an initial filter process that gets rid of larger particles such as leaves and twigs. From here it enters the storage tank where, as it settles, any large particles will float to the bottom of the tank. As water is needed from the tank it goes through a smaller filter before it heads to the house. 

There is not enough annual rainfall in the UK to provide all water needs for a house. Thus the use of rainwater is limited to washing machines, toilets, gardens and dishwashers. Also, the rainwater would have to go through a much stricter (and expensive) cleaning process if it was to be used for bathing or heating systems.

The Storage tank is connected to the Mains Water supply in case it ever runs low of rain water it can then be topped up and continues to supply the necessary appliances.

The cost of the system, including the plumbing for the grey water system is as follows:

 

   

System   Cost

Installation   & Commissioning

Rainwater Harvesting

£3,287.50

£1,850.00

 

 

   

Grey Water System

NA

£850.00

 

Waste Water Heat Recovery:

Waste Water Heat Recovery Systems capture the heat from used hot water and use it to pre-heat the incoming water supply. The systems can capture up to 50% of the heat lost through waste water and are easily installed to new builds and retro-fit properties. 

The system itself is made out of copper piping, a good heat transfer unit: 

The waste water passes through the inner pipe whilst the clean cold water passes through the outer pipe. This transfers heat from the waste water to the incoming cold water supply, where it is then passed to the boiler for further heating. The cold water is typically heated by at least 10 degrees Celsius and thus reduces the amount of energy required to heat the water by the boiler. The pipe measures 2m in length and can be easily installed on new and existing systems. The costs (per unit) are as follows:

   

System   Cost

Installation   & Commissioning

Waste Water Heat Recovery

£890.00

£245.00