Reasons for changing to woodfuel
The previous heating system used radiant and electric panel
heaters that were operated on demand. These were expensive to run
and so were only turned on when needed, this often left the hall
temperature very low, which was uncomfortable for hall users.
Research and investigation found woodfuel to be the best option
over ground source heat pumps, due to the favourable costs of
installation.
System features and benefits
The new
woodfuel system provides constant background heating which serves
to keep the hall at a more reasonable temperature for users, as
well as protecting the fabric of the building against damp.
Originally pellets were delivered in bulk and manhandled into
the fuel store. For ease of use, the store has now been adapted to
accept blown pellet deliveries.
Wood fuel supply
Wood pellets are bought direct from a producer 30 miles away,
and delivered directly into the hopper via a pneumatic blower
attached to the delivery vehicle.
Blown truck loads often have a minimum delivery of about 5
tonnes. One tonne load bags delivered on a pallet are a cheaper way
to receive pellets, but require onsite handling machinery. Buying
in bags can cost up to twice the price of buying in bulk.
Dust socks or filters on the exhaust pipe will reduce dust
build-up. [Virginia: what does this mean?]
Installation issues
The building was completely renovated in 2008. Wall and under
floor insulation were improved to ensure increased heat retention,
further helping to reduce heating costs and energy consumption.
The boiler and fuel store are located within the existing
storage area of the hall, this meant that no additional boiler
house construction was required.
Two universal fitting delivery pipes
into the fuel store are required to accept blown deliveries (the
second pipe allows excess air to escape).
Lessons learned
- It is important that the user fully understands the cleaning
requirements of the boiler to maintain output and reliability
- Delivery methods need to ensure dust creation is kept to a
minimum
- Secure a local fuel source as soon as the development is
conceived
- An internal fireproof hopper can add extra costs to a project -
make sure all costs are identified and included in the budget
- Carefully consider long-term delivery options for pellets.
Blown supplies are most like current fossil fuel deliveries, with
minimal input from the user
Facts and figures
Note: figures are approximate
| Building |
| Fabric |
Breezeblock and timber structure |
| Heating system |
| Boiler manufacturer/model |
Windhager BioWin 260 |
| Maximum boiler output |
25.9 kW |
| Fuel type |
Wood pellets |
| Fuel specification |
Moisture content: <10% (M10) |
| Delivery, storage and handling |
Hopper |
| Store capacity |
5 tonnes (8 m3) usually filled in 3 tonne deliveries |
| Back-up/top-up system |
None |
| Fuel consumption, costs and savings |
| Annual woodfuel use |
12-15 tonnes |
| Annual CO2 savings |
14 tonnes |
| Wood fuel cost |
£1,600 for 26,000 kWh |
| Annual fuel cost saving at 2008/09 prices |
£1,000 |
| Payback period |
n/a - fully grant funded project |
| Installation cost and funding |
| Boiler system |
£24,000 |
| Funding source |
Scottish Community and Householder Renewables Initiative
(SCHRI), Global Environment Facility (GEF) |
| Funding support rate |
60% (SCHRI) 40% (GEF) |