BlueTerra has reviewed the design of an air handling unit system for a storage room. We mainly focussed on the energy saving potential of the chiller and the humidifier. BlueTerra identified an energy and cost saving potential of over 50% for humidification and 40% for the chiller. Once again it showed that reviewing an air handling unit design by an energy specialist from BlueTerra results in significant energy and cost savings.

The review lead to a potential cost reduction of air handling of 8% with a payback of less than 5 years. The customer was delighted by the savings we discovered. In addition we prevented a deficit of heating capacity of the air handling unit.

Humidifier
The figure below represents the costs per mass unit for different types of humidifiers and available energy resources.

As may be expected, and in conformation with the second law of thermodynamics, humidification powered by electricity is most expensive. One would expect that the variable energy costs for district heat is the cheapest, but for this specific case it was not. And finally, using adiabatic humidification beats the efficiency of steam injection.

The cost savings by using natural gas combined with adiabatic humidification instead of electric humidification are over 50%

Design specifications
In addition, the design specifications such as the comfort requirement have been checked for compliance with Dutch national engineering practices. The lowest ambient temperature in the Netherlands (coastal area), which is used for the design, is normally -10°C. However, according to international standards, the design temperature would be -7°C. Using the latter ambient conditions could lead to serious discomfort and complaints.

Chiller
The proposed chiller did not include all energy efficient features, which are offered by the manufacturer. Saving measures such as:

• variable speed fans for the condenser;
• variable speed drive for pumps;
• enabling energy performance monitoring;
• heat recovery by utilising the superheating of the condenser for heat supply.

In total this amounts to over 40% of energy saving for the chiller.

Do you also want to maximise cost and energy savings? Let an energy specialist review your design and contact Allan Hart by email allan.hart@blueterra.nl or telephone  number +31 30 69 11 844