Insulation for Reef Tanks

2 December 2012

Introduction

Many reefers use chillers to cool their reef tanks to mimic the environment of the living corals and other ocean creatures. The tank is usually kept in temperature around 25-28C. This article will examine how much energy can be saved by insulating the tanks.

Heat Gains

One of the heat gains of the aquarium is through the glasses which have thickness varies according to the tank capacity. The thickness ranges from 5 mm for a 2 ft tank to about 12 mm for a 6 ft tank. The heat gains or energy losses will vary according to the thickness of the glass; the thicker the glass, the lesser the energy losses. The heat gain through the exposed glasses can be responsible for 50% of the energy losses for a 2 ft to about 12% for a 8 ft tank.

Energy Savings

As aquarium operates 24 hrs/day, the heat gains by the tank is non-stop over the period. These heat gains will have to be removed by chiller; otherwise, the cooling will not be effective. By insulating the tanks with ¼” thick polystyrene foam for all sides except the font viewing panel, as much as 30% of the energy can be saved and hence, the cooling bills.  The thicker the insulation, the more the energy or cooling bills will be saved.

How Much in $ and Cts?

Assuming one has a ¼ hp chiller and a 3 ft tank (36x24x24), the energy saving will be about 10% of the chiller running bills. If we further assuming that the chiller runs about 8 hour per day, the chiller kwh consumed will be about 370watts x 8 hrs/day x30 days = 88 kwh per month. With rate @ SGD$0.2727 per kwh, the cooling bill will come up to about SGD$ 24/=. The saving could be as high as SGD$ 2.50 per month.

Foam As Backdrop

This reefer uses foam to mimic the rocks as a backdrop. This arrangement will improve thermal insulation and reduce heat gains or energy.  It would be more effective if he can also seal the edges of the foam so that there will be no water movement in between the glass and the foam. 

 His tank finally looked like this

Other Relevant Sites 
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