Abstract:
In Heating, Ventilation and Air Conditioning (HVAC), Cool Thermal Storage (CTS), is a
popular demand side management technology for shifting electrical demand for cooling from
peak time to off peak time periods in most of the countries in the world. However this technique
is so far not successfully implemented for building air conditioning systems in Sri Lanka. This
research study shows how CTS is used to reduce life cycle cost of air conditioning system for
Record Repository Building (RRB) in Sri Lanka using CTS under “General Purpose Tariff”
applicable for commercial buildings and “Industrial time of day tariff” applicable for industries
and hotels in Sri Lanka.
TRACE 700 software[3] is used to carry out a computer simulation for modeling of the air
conditioning system of RRB for CTS for different scenarios such as partial storage, full storage
etc against the base case of air conditioning system without CTS under “General Purpose
Tariff” and “Industrial time of day Tariff”.
It has been found that incorporation of partial ice thermal storage for air conditioning system of
RRB the cooling capacity of chiller plants for the building can be reduced by 25% and thereby
initial cost of air conditioning equipment including ice storage tanks could be reduce by 11%
and maintenance cost including ice storage tanks by 8%.
Further it has been found that the annual operating cost of air conditioning system incorporated
with both partial and full CTS for RRB will be lesser than the annual operating cost of air
conditioning system without CTS under General Purpose Tariff (Rate G.P-2) [16&17] as well
as Industrial Time of Day Tariff (Two Part)- (Rate I-2 (T.D.2)) [16&17].
The life cycle cost for 20 years of both partial and full CTS for RRB will also be lesser than the
operating cost of air conditioning system without CTS under General Purpose Tariff (Rate G.P-
2) [16&17] as well as Industrial Time of Day Tariff (Two Part)- (Rate I-2 (T.D.2)) [16&17].
The payback period for air conditioning system incorporated with full CTS for RRB is 8 to 9
years under General Purpose Tariff (Rate G.P-2) [16&17] and 3 to 4 years under Industrial
Time of Day Tariff (Two Part) - (Rate I-2 (T.D.2)).[16&17]
Key Words: Cool Thermal Storage (CTS), Record Repository Building (RRB), General
Purpose Tariff (Rate G.P-2) [16&17] Industrial Time of Day Tariff (Two Part) - (Rate I-2
(T.D.2)) [16&17].
