How to minimise the operational cost and environmental impact of on-premise laundries
Commercial cleaning consultant, BRIAN CLARK questions the long-term cost of operation and environmental impact of top loading versus front load washers, and shares what criteria to consider when choosing washing machines for communal laundries.
Communal laundries in accommodation facilities are often equipped with top loading commercial washing machines. However, a quick look at manufacturers’ specifications shows that top load washers use a lot more water – as much as 130 litres a wash cycle more – than front loading machines and generate a significant amount of wastewater.
As facilities managers strive for greener buildings and lower operational costs, it begs the question – what is the long-term cost of operation and environmental impact of top loading versus front load washers and what are other criteria to consider in building specifications for on-premise and accommodation laundry?
COMPARING WATER IN AND WATER OUT
There are two factors to take into account when looking at water usage and associated costs. They are water in and water out. Water in is the water required to perform a wash cycle, while water out is the wastewater discharge generated. Water in/water out costs vary considerably, depending on a facility’s location and are priced as much as $7 per kilolitre or more in some areas.
The compiled table below shows estimated water usage and wastewater discharge for an accommodation facility with 25 washing machines in communal laundries over a four-year period. For the purpose of the exercise, it is assumed that the machines perform six wash cycles per day over 260 days of the year. The water in usage rates are based on the published manufacturer’s specifications of a commonly used 8 kilogram commercial top loading washer and a new generation direct drive front loading 100-kilogram commercial washer.
As there are different absorption rates with different fabrics and water retention is a factor of spin efficiency, the water out rate is an estimation of 60 percent of water-in in both cases. Water costs are based on 2011 Brisbane water rates of $2.61 per kilolitre and discharge of $1.31 per kilolitre.
The exercise shows potential reductions in water usage of over 19.3 million litres of water and 11.6 million litres reduction in wastewater over a four-year period. Based on Brisbane water charges, there is a potential saving of over $65,841 in water charges alone over the same period.
COMPARING DETERGENT USE
The second part of the exercise looks at the replacement of powdered detergents with automatic detergent feed pumps, which can be fitted to new generation washers. Detergent feed pumps are programmed to introduce liquid detergent and softener in the exact amounts required for the wash cycle and at the correct phase of the wash cycle.
An automated feed system provides potentially significant operational savings, environmental and safety advantages in particular, as user contact with uncontrolled chemicals and detergents powders is all but eliminated, as the chemicals are supplied from a central locked storage area.
As can be seen from the exercise, auto detergent feed systems have the potential to save approximately 9360 kilograms of powdered detergent over four years, with a potential saving of $4350 after taking into account an allowance for the initial cost of the pump system.
The detergent usage factors used in the exercise are taken from manufacturers’ recommended dosage per wash. It should be noted that there can be significant variations in price and dosage between products and that dosage is also affected by soil type, wash size and water hardness.
COMPARING ENERGY EFFICIENCY
Look for commercial washers with direct drive motors rather than the older belt drive type. Manufacturer data indicates that belt drive machines use up to 30 percent more power than direct drive machines. In addition, the regular maintenance requirement with belts, pulleys and gearboxes is eliminated in direct drive units, thus driving down operating costs and reducing energy consumption.
The G force generated in the spin cycles is a key factor in machine efficiency and in reducing energy usage in communal laundries. It can vary from less than 220 G for top loaders up to 413 G for front loaders. Basically, the higher the G force, the better the rinsing, and fabric is far dryer at the end of the wash cycle, meaning less drying time and a dramatic reduction in energy needed to run the dryer. An ideal spin force on a 10-kilogram machine should exceed 400 G on high spin.
Larger capacity washers and dryers mean more throughput. For instance, a 10-kilogram machine provides 25 percent more capacity than an eight-kilogram machine and users may be able to do their entire week’s wash in one load instead of two, providing more savings in water, energy and operational costs, along with improved availability of laundry equipment.
New technology in access control and remote laundry management has the potential to reduce water and energy usage and operating costs even more.
COMPARING SPACE UTILISATION
The biggest cost in community laundry is the size and number of buildings required. The easiest way to ensure the laundry system chosen will take up minimal space is to purchase stackable washers and dryers. Stack machines consist of a commercial dryer stacked on top of a commercial washer.
Stacked machines use the floor space of a single unit and are only available in front loading configurations. It is worth choosing stack washers that can be assembled on-site, as large preassembled units are bulky, heavy to handle and may not fit through doorways.
Modernising the specifications for your communal laundry facilities has the potential to save millions of litres of water, reduce wastewater, minimise detergent usage, provide better wash results and improve user safety. It is an exercise worth doing.