Wood Burning Stoves and Heat Pumps

It might seem like a true backwards step to think of wood-burning stoves as a way to reduce carbon emissions. After all, didn’t we abandon them long ago to move to coal and finally central heating? Can burning wood even reduce a carbon footprint?

The simple answer is that although you’re releasing CO2 into the atmosphere when you burn wood, since it’s a renewable resource, meaning what’s put out is absorbed by tress, and the new growth means things are sustained.

As to going backwards, well, no it’s not. The new generation of stoves and wood-burning boilers are very sophisticated. Granted, it’s not ultra high-tech, but the bottom line is how effective it is.

How It Works

By having a stove with a backboiler, either integral on clip-in (stainless steel is best), you can either supplement or entirely run your hot water and heating system. Unless you’re extremely handy, you’ll need to work with a plumber or heating engineer on the set up of the system, and you’ll need the room for the stove and boiler.

You’ll find that a good backboiler/stove system will have a relatively low output to the room but a high output to the boiler – which, after all, is what you want. It’s possible to obtain grants for boiler systems.

In case you think you have to spend all your time putting in logs and cutting wood, rest easy. Those days are gone, and modern stoves have a 90% efficiency. If you go with wood pellets and wood chips, there are automatic feeding systems which hold enough fuel for 1-3 days, but once again, you’ll also need to have the room for them.

If you’re going to do this properly, be sure you use sustainable timber, from somewhere relatively local, which generally should be no problem.

Depending on what you want to use the boiler for, bear in mind that hot water will take about 8-10,000 BTU, while an average radiator uses in the region of 5,000 BTU.

You can combine boilers with solar heating, since you obviously won’t want to run a wood boiler during the warm summer months.

Heat Pumps

The theory behind heat pumps is incredibly simple – it uses the heat that’s in the ground to warm your house, pushing it out with a ground pump. You will still have to pay for the electricity that runs the pump, but the heat itself is free. The investment isn’t cheap, around £9,000, but it can pay for itself relatively quickly.

What You Need

This is a system that’s only going to work if you have a garden, and one with a reasonable size, at that, so bear it in mind. There are two options, the first involving a trench around 100 metres long, the second, a little easier, or a spiral loops 10 metres long. If space is truly restricted, you can use a borehole.

In the trench, which needs to be a metre deep so it’s below the frost level, a pipe, called a ground loop, is laid to capture the ground heat in a flowing liquid. The liquid goes to the heat pump, which then uses it to heat your radiators.

Again, it’s not a project for novices or even intermediate handymen; you’ll need to work with a heating engineer to make it happen smoothly. It’s possible to obtain a grant from the Low Carbon Buildings Programme.

Of course, either one of these methods represents a significant investment in your property, but both significantly lower your carbon footprint.