Hot Water Delivery System
Hot water at any faucet in 3 to 5 seconds with as little as 1 cup wasted. Now that’s a HUGE improvement.
Studies show that the average home wastes more than 3,650 gallons a year waiting for the hot water to make it to the faucet. According to the same study, 10-15% of the energy used in conventional hot water delivery systems is wasted. That’s an unnecessary burden on your energy budget as well as on our area’s limited water supply and other natural resources.
In the Carmel Point home we’re building, following the Living Building Challenge, one of the solutions we’re using is a demand-controlled circulation system with what the industry calls “structured plumbing.” We like to call it “strategic plumbing.” Here are a few details of our strategic plumbing system:
- One main ¾-inch PEX recirculation loop with short “twigs” rather than “branches” to each faucet
- To maximize flow and minimize mixing of hot and cold water, this line is all “sweeps,” and the only fittings are ¾ x ½-inch tees
- Each tee supplies a fixture with hot water and each fixture has its own ½-inch supply line. The bathtub and clothes washer share a ½-inch line
- All but one of the supply lines are less than 8-feet long containing about 1 cup of water
- When a demand button is pushed or a motion sensor is triggered, the pump sends hot water through the recirculation loop at 4 to 6 GPM and shuts off when the hot water arrives at the last fixture in the loop, taking less than 2 minutes
- Because of well-insulated pipes, the water in the loop remains above 105°F for 30 to 40 minutes
- A signal from another demand button or sensor will not trigger the pump until the water temperature falls below 105°F
- Wired demand buttons can be located at the entrance to the house, bedroom nightstands and the kitchen; motion sensors may work best in the bathrooms, laundry and other locations to suit the owners’ patterns of use
- There is nothing in this system that is outside the existing plumbing code
In every house we build, we look for ways to increase energy efficiency and reduce related waste and costs. This advanced hot water delivery system dramatically reduces both the energy used to heat the water and the amount of water wasted.
Check out the accompanying video on structured plumbing.
