- Prasad Murugesu
- Sri Lanka
Mechanical Design Engineer, Shin Nippon Lanka PVT Ltd.
Taking Payback Period Analysis out of Water Conservation System Designs
Water is the next resource under serious threat by over consumption, after crude oil. But depletion of this valuable natural resource will affect the lives of every living organism in the planet, equally. Pollution, over-consumption and global warming have reduced the number of aquifers drastically.
In the HVAC industry, condensate recovery from AHUs is slowly gaining popularity as an effective water recovery method. Unfortunately it is restricted to cost effective locations, where the cost of installing the recovery system can be recovered by the water saved.
The primary issue here being, why is water saved only via the most profitable methods? Are we that materialistic? Maybe it is time we realized that water should be conserved at all costs.
For example: When recycling condensate water from AHUs, the major task would be to install dedicated, insulated PVC pipe lines, to transfer the condensate from the drain pan to collection tanks etc. Naturally, hot and humid climates produce the highest condensate volume. In most places condensate drain lines are connected to the nearest waste water line.
In countries where potable water costs are comparatively cheaper, water conservation is not widely practiced, instead, frugal consumption is implemented (its effectiveness unknown).
My proposal is to remove payback/cost estimation out of the equation and ensure that any volume of water is conserved in conjunction with intelligent consumption and recycling. Moreover, when there is less water wasted there's less sewerage treatment required. Even though LEED ratings and ASHRAE standards encourage recycling (grey water), potable water recovery should be implemented at all costs. Saving some now is better than none in the future.
[This is an observation made while skimming through ASHRAE articles and research journals. Any valuable insight on why this might be acceptable/ unacceptable to any industry or homes is appreciated.]