Redefining the performance of gas-fired convector heaters
Today’s gas-fired fan-assisted convectors can make very short work indeed of heating churches. Bill Sinclair of Rinnai suggests that the warm-up time would normally not exceed an hour and a hal, with the heating cost for a service generally being under £5 — including pre-heat period.
Forget the heating of village and church halls of your youth. Gas-fired convector heaters have advanced enornmously — as BILL SINCLAIR explains.Fan-assisted, gas-fired convectors are familiar items of heating equipment in churches, schools, community and sports halls. However, they are not without their problems, as Bill Sinclair, technical manager for Rinnai UK, explains. He says, ‘The established old-style convector and its associated problems is an all-too familiar fixture in our industry that dictates how many of us still view convection heating today. Search out
‘Major downfalls such as noisy and inefficient operation, cumbersome and unattractive designs, cold draughts and, more often than not, a dangerously hot outer casing, have caused specifiers to search out for new space-heating technology over using old convector heaters.’ Rinnai, which first brought convection heaters to the UK in 1979 has different ideas, and steady development has led to what Bill Sinclair argues is ‘a strong contender for the perfect space-heating solution’ for the kinds of buildings mentioned above. Among the problems that the latest-generation heaters address is up to 30% of heat generated being expelled via a very-large diameter flue and the lack of a powerful fan to overcome cold draughts — so that the temperature difference between floor and ceiling could be as much as 10 K. Rethinking
Such problems are addressed by rethinking air distribution, with warm air being delivered horizontally through at grille at the bottom of a heater and air for heating being drawn in at the top. This approach keeps warm air in the lower part of the space, considerably reducing stratification. Among other features highlighted by Bill Sinclair as contributing to more efficient operation are fully modulating gas burners combined with power-fuel technology to ensure that the exact amount of air required for combustion is provided. Efficient combustion is combined with a stainless-steel heat exchanger. Effective control
As with any heating application, effective control is the key to efficient operation. Bill Sinclair explains that Rinnai’s approach is based on a combination of highly accurate digital programing and fuzzy logic, which ‘set this convection heating technology apart from its predecessors’. Users can set a number of programs for these heaters, including pre-heating for up to an hour to ensure the space is up to temperature when required. Another enhancement is fuzzy logic that enables units to ‘learn’ their environment and adjust the pre-heat period — minimising wasted energy. Flueing
Installation issues have also been addressed — notably fluing. Bill Sinclair explains that flexible flue extensions enable the installer to fit the flue co-axially or in a dual-pipe formation. A novel feature that he highlights is the flues being designed so that they can pass through plate glass. The range of safety measures even includes child locks on some models and cool-wall technology. A separate guard is available to protect the outlet grilles, which, inevitably, will be hot. Other safety features include flame ionisation monitoring, overheat switch, fan switch, and vent indicator lights to show when they need cleaning. As well as technical advances, Bill Sinclair also emphasises the associated improvement in aesthetics. He tells us, ‘No-one wants a space full of bulky, ugly heaters. Advanced models are compact, streamlined and almost half the size they once were, For example, one of our best-selling commercial gas convection heaters is just 554 mm high, 750 mm wide and 250 mm deep.’ And comparing traditional gas-fired fan convector heaters with today’s equipment, he summarises, ‘At the end of the day, the onset of cutting-edge technology means that convection heaters are a practical, efficient, competitively prices and, most importantly, a safe space-heating solution that just cannot be ignored.’ Rinnai UK Ltd is at 9 Christleton Court, Manor Park, Runcorn WA7 1ST.