Humidifi cation & dehumidifi cation
www.heatingandventilating.net
Choosing the correct humidifi er
Dave Marshall-George, sales director at Condair, reviews the main types of commercial humidifi er on the market
T
here are many factors when considering which type of humidifi er is the best solution for any given project. Installation constraints,
energy use, control tolerance and available budget are just a few. The below gives a summary of the main selection criteria.
Steam
Boiling water to create steam is very hygienic and off ers an accurate way to manage humidity. The most common steam humidifi er incorporates electric heaters, of which there are two types. The electrode boiler humidifi er creates steam by passing current through water in a plastic boiling cylinder. These are easy to install, operate on mains water tend to have the lowest capital cost. They provide humidity to an AHU with a steam lance or directly to a room with a fan unit. The removal of limescale, which makes up the biggest service requirement, is just a matter of draining and replacing the cylinder with a new one. This is quick and has minimal downtime.
10 January 2025
The control available with these units is quite wide at around ±5%RH. This is because fresh water needs to be added to the boiling chamber to manage mineral levels, which causes an occasional drop in steam output.
If tighter humidity control is needed, the electric
resistive steam humidifi er is a good choice. Rather than passing current through the water, it has heating elements a bit like a kettle. This means the steam cylinder can be made of stainless steel and the limescale is simply emptied, rather than the cylinder being replaced. Unlike the electrode, which needs the minerals
Left: Dave Marshall-George, sales director at Condair
in the water to conduct electricity, the resistive humidifi er can operate on demineralised water. By removing the minerals in the supply water, limescale formation is minimised. This reduces servicing and the need to introduce fresh water to control mineral concentrations, thus enabling this type to provide ±2%RH control. If large capacity humidifi cation is needed, gas-
fi red steam humidifi ers can be a good solution. However, this type is becoming less popular given the need for buildings to decarbonize, and electricity now being seen as a more sustainable solution. If a building has existing central steam or high temperature hot water available, heat exchanger steam humidifi ers are also a possibility.
DOWNLOAD THE HVR APP NOW
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32
