Technology installed:

A MCZ Musa Hydro pellet burning stove, a new hot water cylinder and radiators.

Generating capacity:

13kW

Property:

Two bedroom semi-detatched

Installation date:

2011

How it works:

Wood pellets are fed into a fuel hopper on the top of the stove. When activated (either by timer or manually) the stove fires up and the pellets are released in the combustion chamber. Once on the stove modulates its output depending on the needs of the user ie. burns more chips when more heat is required. Water is heated and transferred to the radiators and to a separate unvented hot water cylinder for domestic hot water.

What is it replacing?

Electric storage heaters and an electric boiler. During winter this system was costing £65-70 per week.

Who installed it?

Green Flame Stoves- Supplier (John Lawrie-installed it)

Installation cost:

Approx. £9,000

Grant/Funding received/will receive (FiTs/RHI etc):

Renewable Heat Premium payment of £950 (grant), and will possibly be eligible for the Renewable Heat Incentive payments when they come in (expected spring 2014), current suggested tariff is 5.2-8.7p/kWh for biomass burners. The owners do not have cavity wall insulation which could hinder any future RHI payment. The owners have decided not have cavity wall insulation due to neighbours properties being treated for damp problems after the insulation was done.

Any planning issues:

None

Inconvenience/disruption levels of installation:

The owner found the installation process very disruptive as all the floor boards needed to be raised to install the new radiator system. This process took approximately five full days (9am-6pm).

How long did it take to plan/install:

The owners looked into options over a couple of months but once they had decided on a technology the process was fairly swift.

Noise/smell issues:

There is minimal smell which is not too indifferent from normal wood burning but the owner does find the noise levels intrusive. When the system starts up it makes quite a whiney noise and then the combustion process has quite a roar to it. The internal fan has been disconnected and this has reduced the noise level – but it is still fairly noisy.

Onward running costs/needs:

The burner requires woodchip pellets which the owner buys in by the pallet (approx 150 10kg bags). One bag costs £2.60. The burner also requires regular cleaning to remove ash from the grate and filters (at least every few days). The owners found that it was necessary to purchase a new/separate vacuum cleaner to perform this task. Additionally the air filter at the back of the stove needs cleaning every two to three weeks.

Owner’s comments/advice:

Although the owner acknowledges that the house is warmer than with the old storage heaters and that the cost is cheaper (approx £49 (pellet plus electricity) per week in winter compared to £65-70 before) they are not completely satisfied with the pellet burner. The installation requires a lot of effort to keep running via the delivery, storage and manual feeding of the pellets, and then also the cleaning of the stove. The owner has to keep the pellets in a garage which is separate from the house, this means that the pellets are delivered to one place, manually hauled to the garden in smaller amounts and then loaded into the machine (1 ½ bags per day). This continued physical effort does concern the owner. Additionally the owner feels that the running costs and noise levels are higher than expected.

If you did it again would you do anything differently?

The owner feels like that it perhaps would have been worth paying a little more to get an air-to-water heat pump.

Recommend the technology:

No, but would recommend the installer.

Estimated payback time:

Approx 16.5 years (based on a savings in heating/hot water costs between £546 per year)

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