Regulation 75 Calculation of heat loss in certain circumstances
This regulation applies to participants who own an accredited RHI installation for which an application for accreditation was made on or after 24th September 2013.
Where the Authority is satisfied that relevant piping complies with the requirements in paragraph (3)(a), (b) or (c), the heat lost through that piping may be disregarded when determining the kWhth of heat generated by the plant which is used for eligible purposes.
The requirements in this paragraph are that—
each length of piping which is 10 metres or less and situated outside a building is properly insulated;
each length of piping which is greater than 10 metres and situated outside a building is—
properly insulated, and
the average annual heat lost from all such piping based on a heat loss calculation is less than 3% of the projected annual heat output of the plant; or
the piping is situated inside a building.
Where relevant piping which is properly insulated is—
situated outside a building;
each length of such piping is greater than 10 metres; and
the average annual heat lost from all such piping is more than 3% of the projected annual heat output of the plant,
a heat loss calculation may be used to establish the heat lost from such piping when determining the kWhth of heat generated by the plant which is used for eligible purposes.
A heat loss calculation may be used to establish heat lost when determining the heat generated by the plant which is used for eligible purposes where in the opinion of the Authority—
physical constraints, reasons of safety or environmental conditions mean that it is not reasonably practicable to install a class 2 heat meter or steam measuring equipment;
a class 2 heat meter or steam measuring equipment would provide less accurate results than a heat loss calculation;
the cost of installing a class 2 heat meter or steam measuring equipment would be disproportionate when compared with the total installation cost of the plant; or
the administrative cost to the Authority of processing information from a class 2 heat meter or steam measuring equipment would be disproportionate when compared with the amount of heat which may be measured.
Where in addition to heat supplied by the plant—
heat generated solely by gas or electricity is supplied to the same heating system of which the plant forms part; and
one or more meters are installed which measure the total amount of gas or electricity used to generate that heat,
the quantity of that gas or electricity expressed in kWh may be converted into kWhth provided such a calculation is based on an assumption that 100% of the fuel is converted into heat.
In this regulation, “relevant piping” means piping which conveys heat for, or returns heat following its use for, a purpose for which heat is supplied by the heating system of which the plant forms part.