Rain Tank Analyser
This software is intended, primarily, for sizing raintanks for domestic use of water -- in-house as well as outdoors, if required: however, there is a limit to storage volumes - 20,000 litres. The model can also be applied to commercial/industrial situations provided the 20,000 L limit is recognised. In (these) situations where very large catchment (roof) areas are available, then a solution to the problem of "sizing" can be found by segmenting the catchment so that each segment requires a rainwater tank of capacity not exceeding 20,000 L.
The main features of the analysis include three graphs:
Upper display: this shows two curves giving "% supplied", meaning "% of annual demand that is supplied" (orange curve), and "Yield, kL"(blue curve). Information obtained from these curves can be related directly to any selected tank size (kL) within the range presented on the horizontal axis. The display includes a "suggested" size for the tank storage.
Middle display: this includes the same "Yield, kL"(blue curve) as above, plus a green curve which provides economic information as "cost per kL" of raintank water delivered to the household or business. [Supporting economic analysis information is included in the Data sheet.] A minimum cost per kL can be deduced from the curve by inspection.Bottom display: this includes the same "Yield, kL" (blue curve) as above, plus a purple curve which provides supply information relating to the number of days that the tank is empty. There may be additional days where the tank can supply part of the daily demand.
Please click on the this link raintankBETAv2 (4 Mb)
Please note some aspects of the analysis may not function with version of Excel preceding 2003.