Rain Water Feasibility:

Data required:

Average sleepers per day: average of sleepers per day during the whole year.

Annual rainfall: the data of the specific region must be inserted. This can be obtained from the folllowing Met Office link: www.metoffice.gov.uk.

Main roof hotel area: the area that is going to be used to collect the rainwater in m^2.

Potential collection areas: any other remaining useful collectable areas.

Specify Roof Surface Type: in order to obtain the Runoff Coefficient, the material used in the roof has to be selected from the list.

Estimated Annual Demand: choose more specific demand starting from the most commonly use to the less, in order to realise if the rainwater is enough to meet the following purposes. Garden use, toilet flushing and washing machines are the main usage, but rain can be used for showers and baths.

Garden Use:
Days per year: estimation of the number of days that the garden will be watered.
                        Specific water capacity: estimation of the litres consumed.

Use of water in Common rooms:
Times per day: estimation of times per day toilets is used. The tool takes into account the average number of sleepers per day.
Specific water capacity: the water consumed by each one of the previously

Also, estimation of times per day washing machines and dishwashing machines are used.

Use of water in Guest rooms:
Times per day: estimation of times per day that each of the three different services (toilet, bath and shower) are used. The tool takes into account the average number of sleepers per day.
Specific water capacity: the water consumed by each one of the previously

Output:

Annual collectable rainwater and the collectable water per day: potential collectable water in order to compare it to the total annual consumption.

Total water consumption: takes in account the usage (per day or per year) and consumption estimated to calculate the total water consumption per year (m^3) for the following items:

• Garden use

• Common rooms
• Toilets
• Washing cycles
• Dishwashing cycles

• Guest rooms
• Toilets
• Baths
• Showers

Average amount of water required: estimates both daily and annually the amount of water required to satisfy the demand.

• Daily, annually in common rooms
• Daily, annually in guest rooms

ANNUAL consumption in Guest Rooms and Common Rooms: adds the annual consumption of both areas (common and guest rooms).

Sufficient roof water available: shows if the collectable rainwater is enough to meet the specified demand.

Rain Water Financial Analysis:

Data required:

Current water use cost: divides the total water cost in four different categories:

• Quarterly water supply bill
• Quarterly sewage bill
• Quarterly drainage bill
• Total Quarterly Water bill

Capital costs: divides the budget used to finance the project in five different categories:

• Site preparation costs (number of hours taken*hourly rate)
• Purchase of components (tank, filters, pumps, electrical, wiring control)
• Collection and distribution pipework
• Installation and commissioning

Operating costs: once the rainwater harvesting system has been installed there are some operating costs that have also to be accounted. These are divided in five categories:

• Annual consumables
• Annual electricity operating costs
• Labour cost from maintenance costs

Water unit cost: the price in pounds per m^3 of the water used.

Fixed charge/quarter: the price in pounds of the fixed charge paid quarterly.

Incentive grant (ROC): amount in pounds of the grant received for the installation of the rainwater harvesting system. for hotels it can be all the capital cost.

Output

Current water use cost: gives the amount in pounds that can be saved with the use of this system for the specified parameters in four different categories:

• Annually water supply bill
• Annually sewage bill
• Annually drainage bill
• Total Annually Water bill

Potential water savings: Gives the following values:

• Total annual collectable rainwater
• Annual financial Water Savings
• Revised annual Water Bill

Total capital costs and payback:

Incentive grant (ROC): amount in pounds of the grant received for the installation of the rainwater harvesting system, for hotels it can be all the capital cost.

Total operational cost per annum

Payback period (years): shows the years needed to amortise the invested amounts.