FAQ
Can I use a wood fuelled boiler in my house?
Wood fuelled boilers can be used in both the domestic home, country mansion and commercial or community premises.
What size boilers will I need?
Rough guide for heat loads, domestic house 10-30kW, Farm house 30-50kW, mansion 75-150kW.
Take a look at our Boiler sizing worksheet
What does Carbon Neutral mean?
Carbon dioxide (CO2) taken from the atmosphere by trees during their growth – when they decay or are burned the (CO2) is released back into the atmosphere. In a managed woodland or energy crop the fuel burned is balanced with new planting so the crop is carbon neutral. Mature forests give off and use an equal amount of (CO2).
What types of fuel are there?
Log, chip and pellet.The more handling the wood fuel is subjected to the higher the cost therefore logs have the lowest cost and pellet the highest. Pellets are made from compressed sawdust waste products and is appx. 8x25mm in size. Chip fuel if handled efficiently is the cheaper fuel per kW supplied (if comparing to oil and LPG). Chip is made from forestry thinnings and the chip must be of suitable quality.
 |
|
 |
| Logs | Chips | Pellets |
What do I need to think about when considering a Chip Store?
Chip store design is an important aspect of successful chip storage.
80% of the cost of wood heating during a typical life span of 25 years resting with the fuel - not installation, getting it right must be a priority from day one. Consider how the fuel will be delivered, stored and used.
Is there another way to cover the chip?
TopTex protection fleece
TopTex - covering the pile of wood chips with a commercially available fleece. 4m roll x 50 mtrs and 5m roll x 50 mtrs at .88p per square metre - roll price (4m) £242.05 incl VAT and carriage. (5m) £293.75 Price per roll incl VAT and carriage.
TenCate Geosynthetics (UK) Ltd
Unit B2 Haybrook Estate
Halesfield 9
Telford
Shropshire TF7 4QW
T: 01952 588066
F: 01952 588466
E: c.watkins@tencate.com
W: www.tencate.com
How to convert BTU to Kw
To convert BTU to Kw divide by 3,400. Therefore 50,000 BTU is equal to appx. 15kw.
What are the fuel costs?
If you spend £500 per year on oil, consider a log boiler, if more than £1,000 a wood chip system. Logs locally here (at time of writing) are £40 per tonne and oil at 39p per litre. Wood chips at £40-50 per tonne at 20-25% moisture content, give heating 1.6p per kW hour. Heating oil at 39p per litre gives 3.9p per kWh. Heating with LPG at 20p per kg gives 2.32p per kWh- LPG is currently 31.45p.
Pellet are easiest to handle. Check with your local supplier for pricing and delivery.
What about Moisture Content (MC)?
If the MC is >30% chip will compost, If the MC is a low percentage this will result in high blade wear, higher energy consumption and particle breakdown and prouduction of dust. Rough guide for moisture contents, Log 20%, Chip 20%, Pellet 8-10%.
It is important to consider quality of chip (or log) and the moisture content. Too wet and it does not burn well, too dry and it burns too quickly - aim for around 20-25%.
To calculate moisture content %
= we weight of sample - dry weight of sample x 100
_____________________________________
wet weight of sample
Moisture meters are available commercially, such as
http://thermometer.co.uk/31-moisture-meters-damp-meters
Chip Volume / Weight
Conversion of dry (20-25% moisture content) wood
_________________________________________
1 tonne = 2 cubic metres of solid wood = 4-5 loose
cubic metres of chip*
*bearing in mind that chip size will have an effect, contents can settle in transit and density of wood varies.
To convert BTU to Kw divide by 3,400. Therefore 50,000 BTU is equal to appx. 15kw.
