This case study describes how using the The Enovative Demand Controller helps to reduce pinhole leaks on a hot water recirculation loop.
To better read the article, please use the fullscreen option in the lower right corner of the article or download below.
Pinhole Leak Case Study Text:
Summary In 2009, master plumber Kevin Bennett began conducting research to find a solution to a client’s pinhole leak problems. The client was the owner of the Family Tree Apartment complexes in Santa Clara, California. Bennett’s research identified that the problem was being caused by the continuous operation of the domestic hot water recirculation pump combined with hard mineral content of the water. By upgrading the buildings to Enovative Group’s D’MAND CIRC, the damaging effects of hot water circulation were significantly reduced, allowing the owner substantial savings in plumbing repairs.
Methodology The first suspected cause of the pinhole leaks was thought to be within the Family Tree Apartments’ water, which has its source in the local ground wells around Santa Clara. The water from these wells contains very high levels of minerals and sediments, creating the conditions for naturally occurring hard water. This high level of water hardness could potentially be very corrosive to the plumbing, so to confirm this theory Bennett conducted an independent test of the site’s mineral levels.
Existing methods for softening water are prohibitively expensive and impractical, so Bennett’s research into recirculation pumps gave him the idea for a creative alternative. Instead of reducing the amount of corrosive material in the water, Bennett realized that he could instead reduce the amount of time that the water was circulating and causing the corrosion.
With this theory in mind, Bennett contacted Enovative Group to install their new cutting edge recirculation pump, the The Enovative Demand Controller. A recirculation pump is a device that is used to increase the flow of hot water in larger buildings, meaning that building residents can get their hot water fast. What sets the The Enovative Demand Controller apart from other recirculation pumps is that it monitors both water flow and the water temperature in return lines, and based on this information it automatically turns off when there is no need for more hot water in the building. By turning off, the amount of high speed water flow is significantly reduced.
This new technology was exactly the solution that Bennett had been looking for, so he had Enovative Group send over a team to make an assessment and help install the D’MAND CIRC technology. Enovative Group surveyed the plumbing set-up and installed data loggers on the site to gather weekly data.
Findings Bennett’s independent tests of the Family Tree Apartment’s water revealed that the mineral content on the site was at a staggering 370 parts per million (ppm), which is almost four times more than the average “acceptable” range of between 15 and 100ppm. Such high concentrations of hard water indicated that the mineral content was almost certainly one of the primary causes of the pinhole leaks.
These high mineral levels in Santa Clara’s very hard ground water end up causing trouble because of microscopic reactions that occur when the minerals reach high temperatures as a result of heating. The result is that about 90% of all pinhole leaks occur on the hot water line, and not in the cold pipes. This is why recirculation pumps end up playing a big role in the creation of pinhole leaks. A typical pump is always running, meaning that there is always hot water circulating through the pipes at a high rate of speed, and therefore the corrosive effects of the hard water are always taking place in the pipes.
After Bennet had replaced the old pump with Enovative’s D’MAND CIRC, the pump’s runtime at the Family Tree Apartments was reduced from 24 hours a day to only 1.1 hours per day. That is a 95% reduction in pump runtime, which translates into 95% less corrosion occurring each day from hard water.
The success of the The Enovative Demand Controller was partly aided by the unique layout of the Family Tree Apartment building, which had a fully exposed, 260 ft. long return line stretching the entire length of the building. The Enovative team was thus able to attach the pump’s temperature sensors a full 260 ft. away from the water heater, allowing for a much greater efficiency in the pump’s response time to shut itself off. This means that, other than the 1.1 hours a day that the pump is running, this entire length of return line was able to be left cold instead of hot, eliminating 23 hours of corrosive effects.
Conclusion For Mr. Bennett and his client, the results that have come about from the The Enovative Demand Controller turned out to be above and beyond their expectations. Simply by installing a new pump that runs based off of user demand, the corrosive effects of their city’s naturally occurring hard water were greatly diminished without any need to change the composition of the water itself. The cost of the technology needed to soften water is much more expensive than installing the The Enovative Demand Controller, nor does its product lifetime come anywhere close to Enovative’s new pumping control system. An added benefit is that the technology in the The Enovative Demand Controller was originally designed to conserve energy, so the owner will also be receiving significant savings on his utilities bill as well. After seeing the successful results of their new pump, the owner has had one installed in every one of his buildings at the Family Tree Apartments, and has been spreading the word to his neighbors as well.