Posts Tagged ‘BTU’

Learning about firewood – The Basics

admin | July 22nd, 2010 | No Comments »

firewoodFirewood is any wood like material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form.

Firewood is a renewable resource. However, demand for this fuel can outpace its ability to regenerate on local and regional level. For example in some places in the world and through history, the demand has led to desertification. Good forestry practices and improvements in devices that use firewood can improve the local wood supplies. As a Biofuel, some consider firewood to be a form of solar energy and to be relatively carbon neutral.

Firewood terms
Since firewood has been used by humans for a long time, there are many terms and concepts to describe it.

North America
Firewood can either be seasoned (dry) or unseasoned (green). It can be classed as hardwood or softwood. In most of the United States, the standard measure of firewood is a cord or 128 cubic feet, however, firewood can also be sold by weight. The BTU value can have an impact upon the price.

Harvesting firewood
Harvesting or collecting firewood varies by the region and culture. Some places have specific areas for firewood collection. Other places may integrate the collection of firewood in the cycle of preparing a plot of land to grow food as part of a field rotation process. Collection can be a group, family or an individual activity. The tools and methods for harvesting firewood are diverse.

North America
Some firewood is harvested in “woodlots” managed for that purpose, but in heavily wooded areas it is more usually harvested as a byproduct of natural forests. Deadfall that has not started to rot is preferred, since it is already partly seasoned. Standing dead timber is considered better still, as it is both seasoned and has less rot. Harvesting this form of timber reduces the speed and intensity of bushfires. Harvesting timber for firewood is normally carried out by hand with chainsaws. Thus, longer pieces – requiring less manual labour, and less chainsaw fuel – are less expensive and only limited by the size of their firebox. Prices also vary considerably with the distance from wood lots, and quality of the wood. Buying and burning firewood that was cut only a short distance from its final destination prevents the accidental spread of invasive tree-killing insects and diseases. Generally speaking, a distance of 50 miles (83 km) from cut site to final burning site is considered the longest distance that firewood should be moved.

Normally wood is cut in the winter when trees have less sap so that it will season more quickly. Most firewood also requires splitting, which also allows for faster seasoning by exposing more surface area. Today most splitting is done with a hydraulic splitting machine, but it can also be split with a splitting maul.

The above text is available under the Creative Commons Attribution-ShareAlike License. Originally written at http://maps.thefullwiki.org/Firewood

Calculate potential outdoor furnace energy savings

admin | July 7th, 2010 | No Comments »

One of the first things you should do before purchasing an outdoor furnace is to calculate your energy costs. Take these numbers and compare them to the potential costs of installing and running an outdoor furnace and we think you’ll find that the the financial benefit is there. And of course, the environmental benefit is a given.

For the calculation, you’ll need to know the amount of heat created or used in your home or business. It’s is measured in BTU’s. An average home uses 200,000,000 BTU’s of total energy for heating per year. Approximately 25% of that number is exclusively for hot water. Depending on your appliances, you could be higher or lower. Also, with how your home is insulated, the types of windows, etc, you may use more or less energy. However, using the average home and based on this total consumption, the following amounts of fuel would be required to produce 200,000,000 BTU’s.

Heating Method Annual Requirements Cost Per Unit Total Annual Cost
Electricity
58,600
$0.08
$4,688
Propane
8,264
$0.89
$7,380
Fuel Oil
5,509
$0.54
$2,947
Natural Gas
5,665
$0.21
$1,207
Wood (Birch)
8.5
$75.00
$638

The data above was provided by outdoorfurnaces.org and all the prices are in Canadian funds. However, using simply math in a chart like this spefic to the costs in your area, you’ll get a good idea of your potential savings.