Module B1 Study Book - the Graduate School of the Environment

Apart from energy labelling, there is also another way of assessing products.
The Eco Design of Energy Using Products Directive is introducing Minimum
Environmental Performance Standards (MEPS). The aim is to take the worst
performing products of a product category off the market. However, this is
only applicable if total EU sales per year are more than 200,000. In the case
of hot tubs we have to assume that with about 10-15,000 annual sales in the
UK, the total for the rest of the EU will not be in excess of 200,000 (DEFRA
2006 online).
It does seem strange that the above directive only takes into account numbers
of products sold without taking into account the value of the product and the
energy consumption per product.
Ideally, energy labelling and MEPS should highlight the worst performing
hot tubs and stop their production. The information of energy labelling would
show consumers the true cost of a hot tub over its lifetime, and will help them
to make a more informed purchasing decision.
The challenge is to compare energy consumption, taking into account the
many variables that influence the performance. The basic testing procedures
have to set fixed parameters for:
• ambient temperature (eg. average UK annual temperature is 9°C);
• water temperature (eg. around 38°C);
• filtration settings of the pump(s) (eg constant or specific amount of
time per hour);
• heating setting of the pump(s) (eg constant regulated by thermostat
or limited specific amount of time per hour);
• usage (eg half an hour, 6 days a week).
With these parameters set, the differences in energy efficiency will come
from:
• volume of water in the hot tub (approximate range between 800 and
1800 litres);
• cover type/thickness (approximate range between 5 and 15 cm);
• type and efficiency of pumps (eg separate small pump for heating
only is more energy efficient);
• shell insulation (thickness of foam around the acrylic shell);
• type of additional insulation (ranges from no insulation to special
insulation guards or full foam);
• availability of timers (eg sleepmode for nighttime or other downtime).
3. The future: Reducing energy consumption and introducing
renewable energy solutions
3.1 Manufacturers
Manufacturers of hot tubs are working on more energy efficient versions
through panel insulation, pump and heater types, settings, and covers.
However, they do not have any plans at the moment to develop hot tubs with
sources of renewable energy, or develop hot tubs that can be connected to
Student Essay: Mirjam Lytton-Lange 201