Gibbons humidification systems produce huge energy savings, particularly when steam humidifiers are replaced.This guide is intended to show how very large energy savings can be achieved, particularly where there is a re-circulated air component to the air handling system and a steam humidifier. This document describes the principles for energy saving by changing the humidification system. Precise energy saving calculations have to be made on a case by case basis.

How the old designs are working

In times past offices were only moderately populated. Computers were mainly used by the secretaries and perhaps a few senior managers. Energy was cheap and no one had heard of global warming. This was the time when chiller systems only worked hard in the summer and humidification systems were steam. In recent years, the use of offices has changed quite dramatically. It is now common to have a computer on every desk. The drive for ever increasing efficiency has lead to large increases in building populations, quite often far beyond the projections of the building designers. Chillers that were once adequate, are now working hard and in many cases have been upgraded to cope with the increasing heat gain. Against this back drop, the use of steam humidification, which puts large amounts of thermal energy into the building is beginning to look increasingly untenable. A possible solution would appear to be increasing the amount of fresh air into the air handling unit. Certainly, increasing the amount of cool air into the system would take load off the chillers. The problem with this solution is that in winter, the outside air is very dry. The humidifiers would have to work harder and pump considerably more energy into the building; energy that has to be paid for. Increasing the loading on the steam humidifiers (particularly electric steam humidifiers) will, in most cases, make them less reliable and increase the maintenance bill.

The Solution — The Gibbons Rotary Atomiser Humidification System

The term “adiabatic” means that heat energy is not put in or taken out. The Gibbons rotary atomiser humidifiers work on the adiabatic principle. The Gibbons humidifier makes use of the thermal energy in the air to evaporate the water. As the water evaporates, the air becomes cooler. It would be normal for the air temperature to drop by up to 5ºC in a re-circulated air system, depending on the amount of humidification required.

How big are the savings?

The Gibbons humidification system uses less than 1% of the energy required by an equivalent steam system at full load. In short, the savings are enormous and it gets even better. If there is a cooling load throughout the winter, the energy that would have been put in by the steam system no longer has to be taken out. For example, if a steam system has a power consumption of 100 kW, replacing it with the Gibbons system will reduce the energy consumption to around 1 kW. A chiller system with an efficiency of 75% would have to remove 99 kW less, giving a saving to the running of the chiller of almost 25 kW. Total power saving 124 kW.

Even more savings!

It would now be possible to make use of the free cooling from mixing in more of the cool dry fresh air. If properly controlled, the loading of the chiller system can be reduced still further whilst increasing air quality.