One of the credits we’ll be pursuing in our prospective LEED Platinum project is “Efficient Hot Water Distribution System”, which can earn up to 5 points in the LEED V4 Credit Rating System.
The objective of this credit is to minimize energy used to heat hot water and distribute it to the fixtures.
One of the ways to accomplish this is to minimize the length of pipe between the source, (Hot Water Heater), and the fixtures. This is done by either locating the hot water heater in a centralized location, and/or designing the layout so that bathrooms are either placed back to back or stacked one over the other.
In our case, we will be using 1/2″ pex piping. So the maximum allowable length from the hot water heater to the furthest fixture, including the total length of piping, is 40 feet.
This particular project lends itself to this credit because the total living are is so small, 584 ft². And we were able to easily locate the Rinnai Tankless Water Heater in a centralized laundry closet. We chose the Rinnai gas water heater model RUCS65iN as this was perfect for this application.
Larger homes can be more of a challenge. But one way to accomplish this credit in a larger footprint is to have multiple water heaters near each fixture. Small electric water heaters can be concealed in cabinets below bathroom or kitchen sinks. This allows you to bring cold water lines to the heater and heat directly at the fixture as water is circulated through the line.
One of the other criteria of this credit is that we insulate all hot water piping. This includes taping at all joints and Ts, and using min. R4 pipe insulation.
Next week we hope to be at the rough plumbing stage and we will be able to provide illustrations of the information provided here. feel free to post any question regarding Efficient Hot Water Distribution Systems below and keep checking back for updates on other LEED credits being pursued and the methods for achieving them.