There are many ways of reducing water heating bills, and some of them are inexpensive and very effective.
Consider the improvements we list below. The results can be very rewarding.
Plumbing design and insulation
You may achieve great energy savings by improving your hot water distribution system. Pay attention to oversized pipes and long piping runs, or to pipes with insufficient insulation. They are a cause of major energy loss (35% of the total energy use in water heating, in many homes).
The best way to save water and energy is to design an efficient pipe layout.
A concentrated and well insulated plumbing is crucial for energy efficiency.
The length of the piping (between the water heater and fixtures) should be as short as possible.These improvements, in existing homes, may be expensive or may not make economic sense, though they are inexpensive in new construction and in major renovations.
Poor plumbing design and lack of pipe insulation will increase water consumption and energy waste: hot water will loose heat in the pipes, and will cool quickly between draws.
Other design considerations
In new construction, avoid homes with many water fixtures, or with showers with multiple showerheads, or with huge bathtubs and hot tubs. That a sure recipe for water and energy waste.
Buildings should have as few bathrooms as possible. Point-of-use electric water heaters can be important, in peripheral rooms and in hot climatges.
The water heater, whatever its type, should be located as much as possible in a central place, relative to the bathrooms and kitchen; the bathrooms should be located as close to the kitchen as possible (or below or above the kitchen). That’s key for a short piping. Long piping runs are inefficient.
Pay also attention to the hot water lines to the most remote fixtures; they should be insulated and of small diameter. Insulated pipes are very important in cold climates.
Drainwater heat recovery devices are also interesting for reducing energy consumption.
Showerheads and Faucets
If your showerheads use over 2,5 gallons (12 liters) per minute or your faucet is over 1 gallon (4 liters) per minute, consider upgrading them to energy-efficiency showerheads and fixtures. They offer quick payback periods.
Be aware to traditional showerheads. Showerhead flow-rates vary between 1.25 GPM/4 LPM and 7 GPM/27 LPM (Gallons Per Minute/Liters Per Minute). Prefer low-flow (energy-efficient) shower heads, delivering less than 2,5 gallons/10 liters.
These low-flow showerheads will cut hot water consumption in half or more – a reduction that amounts to at least 20.000 gallons (75.000 liters) of hot water per year for an average family of fourt.
New low-flow showerheads (and faucets) are easy to install and have relatively low prices. You can buy them online for less than $10 or $15 (see Amazon, for customer reviews: Shower Heads Low-Rate).
Water heater blankets and insulated hot-Water pipes
Old tank water heaters have a typically low built-in insulation (about R-3), which is too little and a cause of energy loss.
Consider installing an insulation blanket, if it is the case; new-energy efficient water heaters have a high (R-10 or more) built-in insulation.
Hot water (Re)Circulating loops (for Homes with long
If you have to wait a long time for hot water to come to faucets and showers, consider installing a recirculating hot water system. These systems are designed to draw hot water quickly into the faucets and showerheads, in existing homes, with a bad pumping layout. They do not make sense in new homes, designed with a short pumping.
But be aware. Some of them (using timers and thermostats, for continuous mode) are not worthwhile and can waste more energy than they save. Only recirculating systems activated on-demand through buttons are energy-efficient.
Instant water circulation systems are simple to install and comprise a pump (the main component) and also a valve and an electronic controller; they use little electricity and can save a lot of water.
Hot water circulating systems conserve water and save energy. They ensure hot water at the shower heads and faucets without waiting times.
Installing a recirculating system is easy. The components are pre-wired and any knowledgeable contractor will do it in a few hours time. It doesn't require modifications to the plumbing system…
These systems are available through manufacturers (Grundfos, Chilippeper, Metlund-ACT, Upunor, Taco...) and distributors, but also in supply warehouses, home improvement stores and online. Amazon.com sells Grundfos, Laing and the Watts brands, at low costs. For customer reviews on Amazon, see Hot Water Recirculating.
For more information and technical documentation on hot water recirculating systems, see Toolbase, here.
Water heating habits involving baths and appliances
Avoid long showers and full baths. That’s the easiest way of reducing water heating bills: showers are typically the biggest hot water expense.
Pay also attention to the use of hot water by washing machines and dishwashers; do not undervalue the impact of these appliances on your hot water bills. Consider some simple strategies to reduce it; that may amount to many hundreds of dollars over the lifetime of these appliances.