How much does a sluice room machine cost to run? Part 1: Electricity

Cost and Carbon calculator: tooltip: Enter your own information and Recalculate, or click below for prepopulated typical profiles

 tooltip: Number of machines across site to be included
 tooltip: Average number of cycles / runs per machine per day
 tooltip: Power being used when machine is not in operation
 tooltip: Average power (in Watts) over a single cycle
 tooltip: Cycle length in seconds
 tooltip: Cost of electricity in pence per kWh

83,707 kWh
16,155 kg CO2e
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Electricity costs of running your sluice room machines

This is the first in a series of articles where we take an objective look at the whole life costs of your bedpan, pot and bottle cleaning or disposal machines. With the increase in price of electricity we will start with a look at the electrical costs, walk through a simple energy calculator and then look at some ways you can reduce annual bills at your site.

Standby power consumption

Many machines use a small amount of electricity to maintain background processes, bedpan machines are no different. There is a wide range of standby power levels, some bedpan machines require water to be kept up to temperature so it is ready to be used, others heat water on demand as part of the cycle or do not need hot water as part of the process so have much lower levels. This standby power can be determined either from the manufacturer’s literature, by measurement with electrician’s multi-meter, or if it is on a 3 pin plug then an inexpensive domestic appliance meter can be used.

Cycle power consumption

Bedpan machines are filled with a number of items and then run to operate a ‘Cycle’, either to wash and sterilise the bedpans or dispose in the case of disposable medical pulp items. This cycle involves any number of processes such as heating water, making steam, pumping, spraying water and spinning macerator blades. These processes will all take the power consumption considerably above the minimum standby level and although the exact power consumption through a cycle will vary, most manufacturers will state an average energy usage for the bedpan machine through the course of a cycle. 

Cycle length and number per day

To calculate the amount of energy used in a day by a machine we will then need to know the length of each cycle and the number of cycles in a typical day. The cycle length is again usually fixed per machine and can be found in the product literature. Many bedpan machines will have an internal usage counter, so this can be read at the start and end of a period of time, for example week, at the various machines on a site to get a good idea of this. Alternative ways to estimate this are based on rules of thumb such as the average pan usage per day per immobile patient is approximately 1.6. When it comes to comparison rather than absolute cost measurement, it is less important to know the precise number of cycles per day, only that the equivalent values are being compared, i.e. a machine with double the capacity will be run approximately half the number of times.

Getting to a total annual electricity cost

Once you have a good idea of the daily electrical cost of a bedpan washer or macerator on your site, then it is simply a matter of multiplying by the number of machines at your site, the number of days in the year, and the price per unit of electricity (currently 29p/kWh) to generate an estimate of your machine’s annual running costs.

We have filled in some default values including illustrative bedpan washer and an illustrative bedpan macerator based on manufacturer stated data on models popular in the UK. The site size we have defaulted to 10 machines as being typical of a modest sized site with around 100-200 beds, with machines being used on average 10 times per day. Please feel free to contact us if you have any queries, suggestions to improve this calculator or would like us to help review the electricity costs on your site:


Based on these illustrative examples, it is clear that a bedpan macerator costs considerably less to run than a bedpan washer disinfector, with on a like for like basis the cost of macerators being around £500 compared with £25,000 for running bedpan washers on a like for like basis. The capital cost of replacing energy intensive washing equipment for macerators is rapidly paid back if this is the only aspect that is being looked at, there are other considerations of course from a cost and practicality perspective.

Looking at standby energy usage, there are savings to be made of the order 10% by putting any bedpan washer equipment on a timer, however this may be impractical as many sluice rooms are needed 24 hours per day. Certainly reviewing the overall number of washer machines that are actually in regular operation may bring some energy saving benefits if low usage areas can be switched off.

As a welcome addition to any savings generated, there is the automatic reduction in carbon footprint associated with any efficiency improvements.

Electricity cost is only one of a number of aspects of the whole life cost of your bedpan machine, we will look at others next including the costs associated with gas (for any inbound heated water supply), maintenance, cleaning, infection control, product lifespan, any chemicals that are needed for each cycle and the costs of the bedpans themselves.

How the calculation is determined for bedpan machine cost and carbon calculator:

Annual energy usage calculation:

= (Power used during standby over a day + Power used during operation over a day) x 365 x number of machines
= ((Cycles per day x Cycle length) x Power + (86,400 seconds – (Cycles x Cycle length)) x Standby power) x Number of machines x 0.0001

Annual electrical cost calculation

= Annual energy usage x Price per kWH

CO2 Equivalent calculation:

= Annual energy usage x conversion factor [0.193 kg CO2 / kWh]