Calculations and methodology
For the annual and daily hot water costs
The figures for heating water with Logicor's InLine Hot Water System are taken from actual measurements on a real system taken using industry standard power analyser equipment (Precision Power Scope PX8000) from Yokogawa with an accuracy of 0.01%.
Our calculation method for the cost of heating bath water with an Electric Immersion Heater and Modern A-Rated Gas Heater is outlined below.
Last calculations made 18 December 2015.
T1 = Temperature of cold water entering system in Kelvin (K)
T2 = Temperature of hot bath water in Kelvin (K)
V = Volume of bath water (litres)
S = Specific heat capacity of water is 4.18 J/cm3/K
Be = Boiler efficiency (A-Rated is assumed 90%)
EJ = Energy required to heat water in Joules
EB= Energy required to heat water with boiler efficiency adjustment
C = Cost to heat one bath
(EJ) Energy required to heat the water in Joules is therefore :
EJ (in Joules) = S x (T2-T1) x V x 1000
Adjustment to account for the boiler efficiency (EB in Joules) is therefore :
EB (in Joules) = EJ x ((1 + (100-Be)) / 100)
To convert Joules to kWh (1 kWh = 3600000 Joules) is therefore :
EB (in kWh) = EB (in Joules) / 3600000
(C) The cost to heat one bath in kWh is therefore:
C = EB x Energy price per kWh
Logicor (CH) Ltd. Unit 7, Thornes Office Park, Monckton Road, Wakefield, WF2 7AN, United Kingdom
Logicor (CH) Limited is an Appointed Representative of Improveasy Ltd., a company registered in England and Wales (Co. Reg. number 7807352). Registered Office: Manchester Business Park, 3000 Aviator Way, Manchester M22 5TG. The firm is authorised and regulated by the Financial Conduct Authority (FRN 708623). The firm is authorised as a Broker, not a Lender, and offers credit facilities from a panel/one lender. The credit is subject to application and status.