In our last newsletter, we discussed some opportunities and pitfalls surrounding the movement toward low-flow shower head use. In addition to these considerations, another regularly overlooked component of the showering experience is the effect that the shower compartment design has on the bather.
Even though it may not often be recognized, the heat trapped within the shower compartment has a significant impact on how we feel while we shower. The door or curtain traps steam and keeps it close to our skin so that we stay warm, even if the water is not in direct contact with our skin. Since low-flow shower heads deliver less water, they also deliver less heat in the form of hot water to the bather and to the shower compartment. This can result in the bather feeling cooler even though the water is delivered to the shower at the same temperature.
As the amount of heat in the shower compartment is reduced through the use of a low-flow shower head, it becomes important to consider the size of the shower compartment and the use of a door or curtain. A door or curtain installed on a small shower compartment will trap the heat so that the bather is not significantly impacted by the movement of cooler air into the compartment as the steam rises naturally out of the space. In addition, careful placement of the exhaust fan/grille in the space can allow steam to be retained within the shower compartment during bathing and then removed once the bathing activity is completed.
Distance from the bather to the shower head can also have a noticeable impact on comfort. In order to discharge less water over the same bathing area, low-flow shower heads must reduce droplet size and aerate the water so that it has the same discharge pattern of a conventional shower head. During aeration, small droplets of hot water are mixed with cooler air, which decreases the temperature of the water. The further the water travels before it contacts the bather’s skin, the more mixing occurs and the more the water temperature drops. By locating the shower head close to the bather or by giving the bather control via an adjustable height shower head, temperature loss can be minimized. This will help prevent users from increasing the water temperature, thus using more energy, to offset comfort issues.
While there are many details to consider, they should not deter the use of low-flow shower heads. The experience can be successful if you select a shower head that performs consistently without variation in the flow rate, ensure the shower valve is designed to prevent temperature fluctuation at low flow, and pay proper attention to the design of the shower compartment.
– Timothy J. Scharf, PE, LEED AP
Tim is a Principal, a Licensed Mechanical Engineer, and a LEED Accredited Professional. Please feel free to contact Tim for further details regarding the above information.