Pilot Methodology
External data logging equipment is used on the M2G to record daily save and bypass data from the boilers and a temperature data logger to measure outside ambient temperature. There are two methods used to measure the hours run, outlined below. The difference between the two methodologies is that Methodology I aggregates the hours run on a daily basis, whereas Methodology II produces hours run for the period of the trial (save days and bypass days).
Sabien reserves the right to use either methodology, dependant on site conditions and external factors.
Methodology I
1. (a) Data loggers record:
DateRun Time Finish Time
- - -
(b) Temperature logger records:
DateTime in hoursTemperature
- - - - - - 1 – 24 o C
2. Sabien converts the temperature data into o day data, i.e. temperature specific to the
site, using the Degree Day Calculation formulae shown below.
3. Percentage savings are calculated as follows:
4. All pilot equipment is collected at the end of the pilot.
Methodology II
1. (a) Hour Run meters record:
Save Day Hours Run
Bypass Day Hours Run
(b) Temperature logger records:
DateTime in hoursTemperature
- - - - - - 1 – 24o C
2. Sabien converts the temperature data into o day data, i.e. temperature specific to the site, using the Degree Day Calculation formulae shown below.
3. Percentage savings are calculated as follows:
4. All pilot equipment is collected at the end of the pilot.
Degree Day Calculation Method
The method used for calculating heating degree days is as follows:
T = Temperature
Tbase = 15.5oC
DD = Degree Days
When Tmin and Tmax have been found for each day, the calculation is then one of the following:
If Tmin > Tbase, DD = 0
If (Tmax+Tmin)/2 > Tbase, DD = (Tbase - Tmin)/4
If Tmax >= Tbase, DD = ((Tbase-Tmin)/2)-((Tmax-Tbase)/4)
If Tmax < Tbase, DD = Tbase - ((Tmax+Tmin)/2)
Risks & Issues to meeting pilot timeline
Temperature logger goes ‘missing’ from roof or location.
Building load conditions change substantially, e.g. floor closed, new equipment installed, building insulation changed.
Equipment configurations may change during the pilot period and Sabien may not be notified of these changes. Such changes may occur at any point from the start date of the pilot, e.g. BMS control of boilers, BMS strategy
Equipment failure or breakdown resulting in corrupted data due to interference.
In the event of a boiler breakdown during the pilot period (inoperative boilers), Sabien reserves the right to either 1) extend the length of the quoted pilot period, or 2) use only valid data taken from the loggers during the quoted pilot period.
Please Note: Should any of the above events occur during the pilot, delays can be expected to both the duration of the pilot and delivery of the final report.