The Problem – The need for instant hot water
Modern living dictates that buildings shall have hot water available whenever and wherever needed – and preferably instantaneously.
Hot water is normally provided by a boiler in a centralised or localised heating system.
After draw off of hot water at a supply point, the pipe feeding that supply point remains full of hot water which, under static conditions, cools to ambient conditions.
When demand resumes, there is a delay period whilst the now cold water is replaced by water heated from the boiler. The delay is both frustrating and costly, as the volume of the static head of water must effectively be heated each time a tap or valve is opened
Traditional re-circulating System
Virtual instant hot water at taps was provided by a twin flow and return re-circulation system. The length of dead-legs was minimised so that hot water flowed soon after opening the tap, and so wastage was reduced.
This system has numerous shortcomings:
- The flow/return re-circulating pipework and thermal insulation has twice the capital and insulation costs compared with a single pipe system.
- Heat losses from the flow/return re-circulation system are twice those of a single pipe system.
- Maintenance costs are incurred with the introduction of pumps and other items having moving parts.
- Dual pipe systems require twice the space. The system must be balanced.
The Solution- The Hot Wot system
The HOTWAT single pipe temperature maintenance system overcomes ALL of the shortcomings of the re-circulation system.
The HOTWAT self-regulating heating cable is fitted to a single hot water supply pipe to maintain the hot water temperature by compensating for heat losses under no-flow conditions. Compared with a re-circulating system, this results in:
Reduced Capital Costs
The HotWat system requires:
- Half the amount of pipework
- Half the amount of thermal insulation
The cost of the heat tracing system will always be less than this saving.