What could be greener than heating your water with free solar radiation?
There is a way to make most solar water heater installations even greener, more environmentally friendly and add convenience for the users of hot water.
Instant Hot Water Will Save You Water and Money!
Now that you’ve heated your water, it’s time to speed up the delivery to your fixtures. Who hasn’t stood there with their hand in the shower waiting for the water to get hot enough to jump in? Running all that water down the drain while you wait just makes it that much worse. But there is a solution!
Demand Hot Water Pump to the Rescue!
By including a hot water demand pump in your solar hot water system you can reap the benefits of instant hot water and save water and energy in the process. A demand pump simply pumps the hot water from the source, (any kind of water heater including solar) to the fixture at high speed without running water down the drain. When hot water reaches the fixtures the pump shuts off.
Instant Hot Water When You Turn On the Tap!
Now when you turn on the tap you have nearly instant hot water. A typical family of 4 can save over 10,000 gallons of water per year. When you want hot water you push the start button and the pump comes on, pumping the water in loop from the water heater to the fixtures, and at the same time sends the cooled-off hot water in the hot water pipes back to the heater through the cold water piping.
Any Kind of Solar Powered Water Heater
Demand systems will work with any type of water heater including any kind of solar water heater. Direct, indirect, batch, or any other kind of solar installation will work with a demand system.
The longer your pipes are the more you will benefit from the demand pump. The longer the pipes the more wait time you have for hot water and the more water gets run down the drain. Often solar water heaters have more piping than standard water heater installations. This is especially true for batch type systems that have a storage tank of hot water up on the roof.
Indirect systems where a storage tank or water heater has a heat exchanger that transfers the heat from the solar panels to the storage tank typically do not have longer pipe runs than standard non-solar systems.
The only pipe that affects the wait time is the pipe between the water heater outlet and the fixture.
Hot water demand pumps require very little energy to operate, typically less than $2.00 per year in electricity. Other than that, they use no more energy than a home with just ordinary household plumbing with no pumps or anything.
Basically a demand pump does what you would do anyway… turn on the hot water until it reaches the sink. But the demand system doesn’t run the water down the drain, and it usually pumps the water to the fixture faster than just running the faucet full blast.
You can thank your low flow fixtures for the slow hot water.
The speed that the water flows through the pipe is determined by the diameter of the pipe and the gallons per minute of flow. Smaller pipe diameters offer faster water velocities and shorter wait times. Higher flow rates also result in higher water velocities and shorter wait times. You can’t easily change your pipe diameter, but you can increase the flow rate through the pipe by not running the water through the low-flow fixture.
Often bathroom sink fixtures are one gallon per minute or less. That makes for a long wait for the hot water to arrive.
Your solar powered water heater takes care of the water heating energy; now make the hot water delivery system green and efficient by adding the demand pump for fast hot water and water savings. Solar water heating and hot water demand pumps are a perfect combination for ecology and environmentally conscious home owners.
A tankless water heater can be used with a solar powered water heater for those who often need larger amounts of hot water. Modern tankless hot water heaters won’t turn on if the hot water is already hot enough at their inlet, and can add just enough heating energy to bring the temperature up to the set point temperature resulting in more energy savings. Tankless and Solar Combined
And both solar and tankless can still be used with the demand put previously mentioned.