Linked Heating Systems

Linked heating systems are where the wood burning stove and the boiler can be linked together to create a combined heating solution. Solar panels and underfloor heating can also be included in a linked heating system.

Ventilation

The level of ventilation is critical in an energy efficient house. The air-tightness of the house can have a significant impact on the house’s energy rating. Having spent time and money heating the air in a room the last thing you want to do is to allow that air to escape.

An open fire and most room open gas heaters operate with a chimney of 200mm internal diameter. In the SAP calculation a 200mm diameter chimney is deemed to lose 20 cubic metres of air every hour.

The ventilation loss from a chimney with a smaller diameter is half this rate at 10cm³. Most stoves operate on a flue of 150mm internal diameter.

A closed loop stove and chimney system, in which the new generation of stoves take the combustion air directly from outside the house will reduce the air loss from the room to virtually zero.

Understanding SAP

SAP is the Standard Assessment Procedure used to calculate the overall energy efficiency and carbon output of a house.

The program produces a single value for the energy efficiency of the house and for the amount of CO₂ given out. The energy efficiency and CO₂ output of the components of the house are combined to produce an overall result for the house.

A more efficient or less carbon intensive component can be used to compensate for a less efficient/more carbon intensive one.

This method of ‘carbon trading’ within the house means that a less carbon intensive appliance like a wood burning stove can be used to compensate for a more carbon intensive appliance.