Reducing hot tub heating costs – significantly!
Rising energy costs are making many owners to reconsider using their hot tubs, but this solution heats them fast and can reduce energy costs by over 60%!
Hot tubs have seen spectacular growth, both in commercial holiday parks and residential homes. However, concerns are growing over the cost of heating them, due to ever-increasing energy costs.
Most hot tubs are heated by an electric heater which typically raises the water temperature by between 1 and 2 °C per hour. So to raise the water temperature from ambient (approx. 20 °C) to operating temperature (around 38 °C) can take up to 18 hours.
Typical Energy Costs
Historically, the typical cost of heating, using the electric heater, was said to be around £2.00 per day, or £730.00 per year, for a quality hot tub with good insulation.
However, the sharp rise in energy prices has seen heating costs rise significantly to around £8.00 per day, increasing annual energy costs to as much as £3,000.00, which has caused many owners to reconsider the benefit of their hot tub!
Reducing Energy Costs
With mains electricity so expensive, switching to a more efficient energy source, such as mains gas, LPG or Biogas, is an obvious solution. This type of heating system, uses a boiler to provides hot water at up to 110 °C. This heat is then transferred to the spa water via a Bowman heat exchanger. The solution is simple, efficient and has been proven in commercial holiday parks for many years.
Controlling the System
In addition to the boiler and heat exchanger, an electrical interface links with the spa control unit, monitoring water temperature and controlling the operation of the boiler.
How It Operates
The illustration shows how the Bowman heat exchanger is installed in the spa water flow, behind the spa control unit;
1: Hot water from the boiler flows through the heat exchanger, transferring its heat to the spa water circuit.
2: An auxiliary pump returns the water to the boiler for re-heating and re-circulation to the heat exchanger.
3: The system interface connects to the spa control system to monitor spa water temperature by controlling the duration of boiler operation.
4: The interface and auxiliary pump are wired to a mains electric supply via a relay unit.
Significant Energy Savings
The Bowman heat exchanger offers hot tub owners the opportunity to significantly reduce heating costs, compared with electric heating.
In a recent installation, the owner reported that the 1400 litre hot tub was heated from 20 °C to 38 °C in approximately 3 hours. During that time, just 2.8 m³ of gas had been used – cost £3.00 approx. Previously, using electric heating, the energy cost would have been around £8.00!
Much faster heat-up times are an additional benefit. As a typical hot tub electric heater raises water temperature by only 1 – 2 °C per hour, many owners have previously run their heater constantly, to maintain pool water temperature for ‘on-demand’ availability, but clearly, with higher energy costs, that is no longer an option.
In contrast, the boiler and Bowman heat exchanger system, raises water temperature by around 6 °C per hour (i.e. 1 °C every 10 minutes), so the heating can be switched off when the tub isn’t in use, giving further energy savings.
With some system interface units, the heating can also be activated remotely, via a mobile device app, enabling the hot tub to be heated and available for immediate use when owners return home!
Bowman heat exchangers provide the vital link that enables owners to continue enjoying their hot tubs, whilst improving heating efficiency and reducing energy costs significantly!