Sunday, January 31, 2010

Saving energy costs by a simple design change




Think of the last time when you operated a 2-handle faucet. Which handle did you turn first? Was it the left handle or the one on the right? Chances are that if you are right-handed, you turned the left tap first and if you are left-handed you turned the one on the right first. If this was any different, please let me know; I'd be curious to know.

Based on quick internet-based research, it seems that the installation instructions for most 2-handle faucet systems indicate that hot water be connected to the left handle and cold water be connected with the right one.

Given that almost 80% of population is right-handed, what that means is 80% of the times when a faucet is operated, the left handle is operated first, which delivers hot water. Now, I do not have data on whether people prefer hot water when they first operate the faucet but I'd guess that there is a significant combined percentage of people who either prefer cold water or who don't care versus the ones who prefer hot water at the first go.

Given above, to reduce energy costs one may want to interchange the hot and cold water connections at the time of installation i.e., connecting hot water to the right handle and cold to the left handle. This of course can be interchanged if the premise has predominantly left-handed folks. Better yet, with a simple design change, this configuration choice can be made dynamically by having a knob that controls the flow of the water to either handle.

The savings achieved at a single premise due to this change depends on several factors - frequency of opening tap, percentage of left-handed/right-handed people using a particular tap etc and may not be significant however economies of scale can be achieved if the modified faucet was used by a large population.

5 comments:

Ashutosh Thakur said...

great observation! i use my left hand to turn the left faucet. However I always look for hot water first.. since it takes a while before the hot water stars flowing.

Sohil said...

thoda wine pi aur faucet bhul ja:)

mgill said...

This brings up the question why
the cold water faucet is on the right in the first place.
My guess is, most of the time people need cold water and most people are right-handed, so the cold water faucet was designed to
be on the right.

matt arcy said...

As with the QWERTY keyboard there are LOTS of paradigms that will be hard to change. To simply switch the connections, the cost of change can out weigh the cost of beneifit for a long time (e.g. many folks will run the now cold water for a long time waiting for hot, or mistake sinks that are not converted, or there will have to be piping modifications, etc.) beyond the operational and safety factors.

A similar but different solution is to change to a single handle faucit. Now folks get what they want and there is no confusion between old-style and new-style.

Sandeep said...

Thanks folks for leaving comments; sorry I didn't reply any sooner as I didn't have comment notifications turned on.

Mgill, to your comment, in my experience I have found it the other way round... i.e., right handed people use left-hand instead of right-hand to open faucet... my guess is right-hand may already being occupied to lets say hold the toothbrush, or pick up the soap etc.

Matt, I agree about your comment on "conditioning". Moreover, visitors to US face this issue anyways. This issue can be solved by placing some sort of aesthetically pleasing signage on the faucet which indicates which one will deliver hot versus cold water. BTW, the same issue still applies for single-handle faucet... there is no way to really know which way to turn to get hot versus cold water unless already marked on the faucet.