If you are about to begin plumbing a bathroom you should consider the benefits of instant hot water with a hot water demand pump. Your family can easily save thousands of gallons of water every year and experience the convenience of instant hot water when you turn on the tap or the shower.
There are three basic types of systems to solve slow hot water problems. There is the traditional hot water circulating system, the warm water circulating system, and the demand hot water system. Not all of them are green although they all save water.
Traditional hot water recirculation
Hot water circulating pumps require looped plumbing from fixture to fixture with a dedicated return line at the last fixture. It’s extremely wasteful of energy requiring the water heater to work harder and more often to keep hot water in the lines. They won’t work with most tankless water heaters.
Warm water circulating systems
These systems have a small pump mounted under the bathroom sink that operates much like a temperature controlled traditional hot water circulating system, except the control temperature is set much lower. The result is instant warm water at the fixture.
To get hot you still must purge the warm water from the pipes. It’s faster but by no means instant. These systems also fill the cold water line with warm water so if you want cold water you must purge the warm water which of course wastes water.
Hot water demand pumps
Hot water demand pumps speed hot water from your water heater to your fixture without running any water down the drain. With a demand system when you want hot water you push a button to start the system and when hot water arrives at the pump it shuts off.
No hot water gets into the cold water line and when you turn on the tap you have nearly instant hot water. With the pump located under the sink, all the fixtures in the bathroom plumbing have faster hot water. Demand hot water systems are all green.
The demand pump should be located at the furthest sink from the water heater and will service any sinks or fixtures operating off of the main trunk line serviced by the pump.
How much any branched-off fixtures benefit from the demand pump depends on the specific plumbing layout. Short branches will have fast hot water and longer branches will take longer. Usually the main trunk line is ¾ inch pipe with the branch piping usually ½ inch pipe. The water travels much faster in the branch piping due to its smaller capacity.
When plumbing a bathroom try to loop the plumbing from fixture to fixture with the demand pump at the last fixture. Any fixtures plumbed in this fashion in not only the bathroom but in the whole house will have instant hot water once the pump shuts off.
Demand pumps are very green products, not only saving thousands of gallons of water, but requiring very little energy to operate. Typically a demand pump will consume less than $2.00 per year in electricity.
Hot water demand systems will operate with tankless water heaters as well. If you are going to use a demand pump with a tankless water heater make sure it produces enough flow to turn on the water heater.
Hot water demand systems can be very economical as well. A good hot water demand system can be obtained for under $200.00 and any do it yourselfer can install one in an hour or so. Some models can be installed with just supply hoses like your sink already uses and you don’t even have to shut off the water to the house… just the supply valves under the sink.
If you are plumbing a bathroom you can go green and install a hot water demand system, save time water and money and experience the convenience of instant hot water when you turn on the tap.
Saturday, January 30, 2010
Friday, January 29, 2010
Hot Water Heater Problems – Gas Water Heaters
It’s the forgotten appliance, but when you have gas hot water heater problems it can be very inconvenient. Most water heater problems are pretty easy to fix and some are impossible to fix.
I’m going to stick to tank type storage water heaters for this article because storage water heaters are much easier to trouble shoot and repair than tankless water heaters. They pretty much consist of a tank of water over a burner with a thermostat. They are pretty simple and very reliable.
Tankless water heaters are sophisticated high tech appliances. The tankless units have multiple sensors to monitor things like incoming water temperature, outlet temperature, exhaust temperature, and water flow all feeding information to an internal computer. The computer controls things like modulating gas valves and water flow valves. There are error codes and many models even have remote controls.
Typical problems you may encounter with your water heater are things like the pilot light going out or it won’t re-light, pressure relief valves that leak or drip, broken or damaged dip tubes, worn out anode rods, and leaking tanks.
Pilot light problems
Usually pilot light problems are a result of a bad thermocouple. The thermocouple sits directly in the flame from the pilot light and glows red from the heat. The thermocouple generates a small electric current from the heat and the current keeps the gas valve open.
If the thermocouple goes bad the pilot light will not stay lit. Replacing the thermocouple is relatively easy. Usually it’s held in place by a nut. It’s a small tubular shaped metal object with a small diameter metal tube which ends with a fitting that screws into the gas valve.
If the pilot light stays lit, but the burners won’t come one, check to see if the flame is bright blue. A weak yellow flame may not get the thermocouple hot enough for the gas valve to open.
The flame should hit the thermocouple about 1/2 inch from the end. The flame can be adjusted, usually by a small screw on the gas valve. Refer to the owner’s manual for instructions for your specific heater.
Dip Tube Problems
The dip tube is a plastic tube that fits down inside the water heater inlet. It directs the cold incoming water from the water main to the bottom of the tank to keep it from mixing with the hot water leaving the heater.
If the dip tube breaks, the incoming cold water will mix with the hot as it leaves the heater and you will a much lower temperature hot water. Broken dip tubes usually result in symptoms like running out of hot water very quickly, or the water temperature is too low.
Leaking or dripping TP relief valve.
Storage water heaters have a safety device known as a temperature-pressure relief valve that opens if the temperature gets too high or if the water pressure gets too high. Without the TPR valve, also know as a pop-off valve, the water heater can become a bomb.
I just watched a youtube video by mythbusters showing a water heater blowing up… it was very impressive.
The owner’s manuals usually state that you should test your TP valve at least once a year by lifting the handle and releasing some water. In my experience, after you’ve done that there is a good chance it will drip forever.
The only solution I know of for a leaking TPR valve is to go down to the hardware store and buy a new one.
Thermostat problems
Thermostats rarely break down. If they do you might want to leave it to a professional to replace. Gas leaks can be extremely dangerous.
Symptoms that my present themselves when there is a problem with the gas valve are no hot water, or hot water that is too low in temperature. Most often the symptom will be no hot water which you will discover when you get in the shower in the morning.
Smelly hot water
If your hot water smells like rotten eggs, then there is probably bacteria which consumes the anti-corrosion anode rod and releases the gas that smells like rotten eggs. Usually it’s a magnesium rod. You can get Aluminum rods that the bacteria doesn’t eat, or use bleach to kill the bacteria, but it will probably come back.
The aluminum anode rod is probably the best solution. They are easy to replace. They thread down into an opening in the top of the heater that looks just like the inlet and outlets.
Strange noises
Gas water heaters can create some interesting sound effects. The main culprit is sediment buildup in the bottom of the tank. As the burners heat the bottom of the tank steam bubbles can form, and make poping and other sounds as they escape from under a layer of sediment. To solve this water heater problem you must flush the sediment out of the tank.
Milky whitish appearance
Air can get dissolved into the water, and when you fill a glass of hot water it appears milking in color. This is actually thousands of tiny bubbles. Let the water stand for a while and the bubbles will eventually all go away. It causes no harm, just looks odd.
Leaking water heater tank
This is my favorite way for a water heater to fail. When I see a puddle of water forming under the gas water heater in the garage, I know it’s time to call a plumber and have a new one installed. That way I don’t get inconvenienced for long.
The worst kind of failure is the one that gives you no warning. That’s just my opinion of course.
There is no way to fix a leaking water heater tank, it must be replaced.
Recent Article: Motion Sensing for Residential Hot Water Demand Systems It talks about how to use a motion switch or timer to control your demand system and what kind of things you can expect to happen when you do.
I’m going to stick to tank type storage water heaters for this article because storage water heaters are much easier to trouble shoot and repair than tankless water heaters. They pretty much consist of a tank of water over a burner with a thermostat. They are pretty simple and very reliable.
Tankless water heaters are sophisticated high tech appliances. The tankless units have multiple sensors to monitor things like incoming water temperature, outlet temperature, exhaust temperature, and water flow all feeding information to an internal computer. The computer controls things like modulating gas valves and water flow valves. There are error codes and many models even have remote controls.
Typical problems you may encounter with your water heater are things like the pilot light going out or it won’t re-light, pressure relief valves that leak or drip, broken or damaged dip tubes, worn out anode rods, and leaking tanks.
Pilot light problems
Usually pilot light problems are a result of a bad thermocouple. The thermocouple sits directly in the flame from the pilot light and glows red from the heat. The thermocouple generates a small electric current from the heat and the current keeps the gas valve open.
If the thermocouple goes bad the pilot light will not stay lit. Replacing the thermocouple is relatively easy. Usually it’s held in place by a nut. It’s a small tubular shaped metal object with a small diameter metal tube which ends with a fitting that screws into the gas valve.
If the pilot light stays lit, but the burners won’t come one, check to see if the flame is bright blue. A weak yellow flame may not get the thermocouple hot enough for the gas valve to open.
The flame should hit the thermocouple about 1/2 inch from the end. The flame can be adjusted, usually by a small screw on the gas valve. Refer to the owner’s manual for instructions for your specific heater.
Dip Tube Problems
The dip tube is a plastic tube that fits down inside the water heater inlet. It directs the cold incoming water from the water main to the bottom of the tank to keep it from mixing with the hot water leaving the heater.
If the dip tube breaks, the incoming cold water will mix with the hot as it leaves the heater and you will a much lower temperature hot water. Broken dip tubes usually result in symptoms like running out of hot water very quickly, or the water temperature is too low.
Leaking or dripping TP relief valve.
Storage water heaters have a safety device known as a temperature-pressure relief valve that opens if the temperature gets too high or if the water pressure gets too high. Without the TPR valve, also know as a pop-off valve, the water heater can become a bomb.
I just watched a youtube video by mythbusters showing a water heater blowing up… it was very impressive.
The owner’s manuals usually state that you should test your TP valve at least once a year by lifting the handle and releasing some water. In my experience, after you’ve done that there is a good chance it will drip forever.
The only solution I know of for a leaking TPR valve is to go down to the hardware store and buy a new one.
Thermostat problems
Thermostats rarely break down. If they do you might want to leave it to a professional to replace. Gas leaks can be extremely dangerous.
Symptoms that my present themselves when there is a problem with the gas valve are no hot water, or hot water that is too low in temperature. Most often the symptom will be no hot water which you will discover when you get in the shower in the morning.
Smelly hot water
If your hot water smells like rotten eggs, then there is probably bacteria which consumes the anti-corrosion anode rod and releases the gas that smells like rotten eggs. Usually it’s a magnesium rod. You can get Aluminum rods that the bacteria doesn’t eat, or use bleach to kill the bacteria, but it will probably come back.
The aluminum anode rod is probably the best solution. They are easy to replace. They thread down into an opening in the top of the heater that looks just like the inlet and outlets.
Strange noises
Gas water heaters can create some interesting sound effects. The main culprit is sediment buildup in the bottom of the tank. As the burners heat the bottom of the tank steam bubbles can form, and make poping and other sounds as they escape from under a layer of sediment. To solve this water heater problem you must flush the sediment out of the tank.
Milky whitish appearance
Air can get dissolved into the water, and when you fill a glass of hot water it appears milking in color. This is actually thousands of tiny bubbles. Let the water stand for a while and the bubbles will eventually all go away. It causes no harm, just looks odd.
Leaking water heater tank
This is my favorite way for a water heater to fail. When I see a puddle of water forming under the gas water heater in the garage, I know it’s time to call a plumber and have a new one installed. That way I don’t get inconvenienced for long.
The worst kind of failure is the one that gives you no warning. That’s just my opinion of course.
There is no way to fix a leaking water heater tank, it must be replaced.
Recent Article: Motion Sensing for Residential Hot Water Demand Systems It talks about how to use a motion switch or timer to control your demand system and what kind of things you can expect to happen when you do.
Tuesday, January 26, 2010
Gas Tankless Water Heater Prices – Include the Cost of Installation
Include the Installation Price When Getting a Quote!
If you are looking at tankless water heater prices then you might want to consider pricing them at sites that have installation available in your area. Proper installation is critical for tankless water heaters, much more so than standard tank type water heaters.
Even years down the road if the heater breaks down it could be due to improper installation and this can greatly reduce the life of a tankless water heater.
Storage Gas Hot Water Heaters
Good old storage water heaters (gas) are basically a tank with a burner and a thermostat. They are a great do it yourself project. Remove the old heater and put in the new one. Hook up the gas, vent, hot and cold water connections and you are ready to go take your shower.
If the hot water is too hot or not hot enough then adjust the thermostat knob. If you live in an area with particularly hard water you may want to flush your water heater yearly. This will prevent sediment build up.
When gas storage hot water heaters fail it’s usually a leaking tank. The puddle that begins to form is an early warning letting you get your tank replaced without having to do without hot water.
Gas Tankless Hot Water Heaters
Gas tankless water heaters are NOT a simple tank and burner. They are sophisticated appliances with micro computers in them with, sensors, modulating valves, and flow switches. The internal computers monitor variables such as water inlet and outlet temperature, exhaust temperature, gas flow etc.
Tankless hot water heaters require larger venting due to the larger burners, often require stainless steel venting, and larger gas lines to supply the larger burners. Often mounted outside, tankless heaters need freeze protection which is often built into the units. Combine freezing weather and a power outage could be a disaster!
Tankless water heaters are complex in their operation and can often shut down unexpectedly leaving you without hot water. The heater may be working along fine at low flow and when you increase the flow it suddenly shuts off because the exhaust temperature got to high or the gas flow was insufficient. And if it breaks down there is no warning… just no hot water when you turn on the faucet.
Most problems with tankless water heaters turn out to be due to improper installation. Most plumbers are not well versed in troubleshooting modern tankless water heaters, especially any one particular brand.
Because installation is so very important you should have a professional install your tankless heater and a specialist in the brand you are having installed would be a plus.
Electric Tankless Water Heaters
Electric tankless water heaters big enough to supply hot water for a shower typically require a tremendous amount of electricity. The gas heaters require bigger gas lines and the electric tankless water heaters require larger wires. They usually require their own dedicated wires and their own circuit breakers.
In many cases the existing electrical service to the house needs to be upgraded which can be pretty expensive. Be sure to include that kind of cost in your tankless water heater prices if you need to upgrade your electrical service.
You may find that by the time you get the thing installed the price will turn out to be far higher than the cost of the tankless water heater.
Check out my recent article about controlling the Chilipepper with Motion Sensors.
If you are looking at tankless water heater prices then you might want to consider pricing them at sites that have installation available in your area. Proper installation is critical for tankless water heaters, much more so than standard tank type water heaters.
Even years down the road if the heater breaks down it could be due to improper installation and this can greatly reduce the life of a tankless water heater.
Storage Gas Hot Water Heaters
Good old storage water heaters (gas) are basically a tank with a burner and a thermostat. They are a great do it yourself project. Remove the old heater and put in the new one. Hook up the gas, vent, hot and cold water connections and you are ready to go take your shower.
If the hot water is too hot or not hot enough then adjust the thermostat knob. If you live in an area with particularly hard water you may want to flush your water heater yearly. This will prevent sediment build up.
When gas storage hot water heaters fail it’s usually a leaking tank. The puddle that begins to form is an early warning letting you get your tank replaced without having to do without hot water.
Gas Tankless Hot Water Heaters
Gas tankless water heaters are NOT a simple tank and burner. They are sophisticated appliances with micro computers in them with, sensors, modulating valves, and flow switches. The internal computers monitor variables such as water inlet and outlet temperature, exhaust temperature, gas flow etc.
Tankless hot water heaters require larger venting due to the larger burners, often require stainless steel venting, and larger gas lines to supply the larger burners. Often mounted outside, tankless heaters need freeze protection which is often built into the units. Combine freezing weather and a power outage could be a disaster!
Tankless water heaters are complex in their operation and can often shut down unexpectedly leaving you without hot water. The heater may be working along fine at low flow and when you increase the flow it suddenly shuts off because the exhaust temperature got to high or the gas flow was insufficient. And if it breaks down there is no warning… just no hot water when you turn on the faucet.
Most problems with tankless water heaters turn out to be due to improper installation. Most plumbers are not well versed in troubleshooting modern tankless water heaters, especially any one particular brand.
Because installation is so very important you should have a professional install your tankless heater and a specialist in the brand you are having installed would be a plus.
Electric Tankless Water Heaters
Electric tankless water heaters big enough to supply hot water for a shower typically require a tremendous amount of electricity. The gas heaters require bigger gas lines and the electric tankless water heaters require larger wires. They usually require their own dedicated wires and their own circuit breakers.
In many cases the existing electrical service to the house needs to be upgraded which can be pretty expensive. Be sure to include that kind of cost in your tankless water heater prices if you need to upgrade your electrical service.
You may find that by the time you get the thing installed the price will turn out to be far higher than the cost of the tankless water heater.
Check out my recent article about controlling the Chilipepper with Motion Sensors.
Motion Sensing for Residential Hot Water Demand Systems
Using a motion detector to start your hot water demand system can have unexpected results.
Demand systems are meant to be activated and then used quickly. Hot water in your piping cools off quite rapidly. Since a demand system shuts off the pump when hot water reaches it, if you don’t use the hot water quickly it will soon become “warm” water and to get hot you will still need to run more water out of the pipes and down the drain.
How the hot water demand system behaves a short while after being used depends mainly on how long since the system was last used. If the water hasn’t cooled to below 96 degrees the pump will be locked out and won’t start until the water in the pump cools to below 96 degrees F. You will be forced to purge the warm water from the pipes to obtain hot water and end up running that water down the drain.
If the water has cooled to just below 96 degrees… say about 90 degrees, then the pump will run again until it sees a sudden increase in temperature or if it senses water hotter than 96 degrees and then shut off again. Now however, there will be 90 degree water filling the cold water line.
If you begin using the hot water mixed with cold, after a short time the warm water will be purged from the cold water line and you may need to re-adjust the temperature to add more hot and less cold water. More details about how the hot water demand system behaves in different situations. It pretty much depends on the water temperatures in the piping.
Using a Motion Sensor
As you can see, any significant wait after you have tripped the motion sensor can cause an inconvenience and or end up wasting water.
Another thing to consider when using motion sensors to control your demand system is what happens when someone enters the bathroom while you are taking a shower? Depending on your plumbing layout and how long since the pump was last run, it could cause a fluctuation in water temperature like flushing a toilet sometimes does.
This is especially true when you have a tankless water heater. Since tankless water heaters take time to heat the water, typically 10 to 20 seconds, if the heater has been off for a few minutes you may experience a brief “cold water sandwich”.
Before you decide you want a motion sensor to activate your demand system you might consider how often you enter your bathroom when you don’t want hot water. Each time the pump runs and you don’t use hot water you are wasting energy and increasing your water heating bill. This is especially true with tankless water heaters. It doesn’t take many firings of the heater to use more energy than a standard tank type water heater loses in standby loss.
The same things hold true when using a timer based system. You can have the demand pump turn on automatically at say 7:30 a.m. every morning, but if you push the snooze button a time or two you are still going to need to run the pump again when you get to the bathroom.
Since the piping is warm you will get hot water faster but you pay the price in extra energy consumption.
For some people motion sensing to control the delivery of hot water is a welcome convenience, but for many others it would just be a wasteful nuisance.
Demand systems are meant to be activated and then used quickly. Hot water in your piping cools off quite rapidly. Since a demand system shuts off the pump when hot water reaches it, if you don’t use the hot water quickly it will soon become “warm” water and to get hot you will still need to run more water out of the pipes and down the drain.
How the hot water demand system behaves a short while after being used depends mainly on how long since the system was last used. If the water hasn’t cooled to below 96 degrees the pump will be locked out and won’t start until the water in the pump cools to below 96 degrees F. You will be forced to purge the warm water from the pipes to obtain hot water and end up running that water down the drain.
If the water has cooled to just below 96 degrees… say about 90 degrees, then the pump will run again until it sees a sudden increase in temperature or if it senses water hotter than 96 degrees and then shut off again. Now however, there will be 90 degree water filling the cold water line.
If you begin using the hot water mixed with cold, after a short time the warm water will be purged from the cold water line and you may need to re-adjust the temperature to add more hot and less cold water. More details about how the hot water demand system behaves in different situations. It pretty much depends on the water temperatures in the piping.
Using a Motion Sensor
As you can see, any significant wait after you have tripped the motion sensor can cause an inconvenience and or end up wasting water.
Another thing to consider when using motion sensors to control your demand system is what happens when someone enters the bathroom while you are taking a shower? Depending on your plumbing layout and how long since the pump was last run, it could cause a fluctuation in water temperature like flushing a toilet sometimes does.
This is especially true when you have a tankless water heater. Since tankless water heaters take time to heat the water, typically 10 to 20 seconds, if the heater has been off for a few minutes you may experience a brief “cold water sandwich”.
Before you decide you want a motion sensor to activate your demand system you might consider how often you enter your bathroom when you don’t want hot water. Each time the pump runs and you don’t use hot water you are wasting energy and increasing your water heating bill. This is especially true with tankless water heaters. It doesn’t take many firings of the heater to use more energy than a standard tank type water heater loses in standby loss.
The same things hold true when using a timer based system. You can have the demand pump turn on automatically at say 7:30 a.m. every morning, but if you push the snooze button a time or two you are still going to need to run the pump again when you get to the bathroom.
Since the piping is warm you will get hot water faster but you pay the price in extra energy consumption.
For some people motion sensing to control the delivery of hot water is a welcome convenience, but for many others it would just be a wasteful nuisance.
Wednesday, January 13, 2010
Water Conservation, Low Flow Fixtures, and Tankless Water Heaters
Low Flow Fixtures
Now days all faucet fixtures for residential plumbing are low flow devices.
While they do aid in water conservation efforts, they can be a bit inconvenient. They don’t save you water if you are filling a pot, getting a glass of water or where a measured volume of water is to be had. They can be a nuisance when you have to wait and wait for the sink to fill with water, or if you are trying to get hot water to the faucet.
Low flow fixtures cause the hot water to flow through the pipes more slowly, and so it takes longer to get your hot water. This can be especially trying when you have long pipe runs, or when your pipe is under a concrete slab and not insulated.
Slow hot water can lead to water wastage. It can take so long to get hot water at a fixture that many hot water users let the hot water run while they do something else before returning to see if it is hot yet. By the time they come back and check they are running hot water down the drain.
At this point energy is being wasted as well as water and the energy to heat the water being run down the drain is substantial… much more expensive than the water being heated.
Tankless Water Heaters
Tankless water heaters are not water conservation friendly to begin with. It takes a tankless unit longer to deliver hot water than a storage water heater since it has to heat the water first which can take 10 to 20 seconds longer than a storage water heater would deliver it.
To obtain the hot water temperature you desire you typically mix hot and cold water to get the desired temperature. This works fine with a storage water heater but can be a problem with tankless units when lower flows are used.
To turn on the tankless heater you must draw ½ to ¾ gallons per minute, depending on the water heater model you have. The outlet temperature with a tankless unit does not change as long as you don’t exceed the maximum flow, so the minimum flow of say ½ gallon per minute is at the full outlet temperature.
If you need to mix half cold and half hot to get the desired temperature you are then forced to use 1 gallon per minute which can often be a much larger flow than you need or want. This of course results in wasted water being run down the drain.
Hot Water Demand Systems
Hot water demand systems can overcome the inconvenience of slow hot water caused by low flow fixtures. Hot water demand systems pump the water to your fixture fast without running water down the drain. Your hot water is faster and you save time water and money.
A hot water demand system typically locates a small pump under the sink furthest from the water heater. When hot water is desired the user pushes the start button which activates the pump and speeds hot water to the fixture. The cooled off hot water from the last hot water use is returned to the water heater through the cold water piping so no dedicated return line is needed.
Demand systems are especially nice when used with tankless water heaters since you save both energy, with the tankless heater and water, with the demand system while having the convenience of fast hot water.
Solar with Tankless - Water Heater Guide - Water Conservation
Now days all faucet fixtures for residential plumbing are low flow devices.
While they do aid in water conservation efforts, they can be a bit inconvenient. They don’t save you water if you are filling a pot, getting a glass of water or where a measured volume of water is to be had. They can be a nuisance when you have to wait and wait for the sink to fill with water, or if you are trying to get hot water to the faucet.
Low flow fixtures cause the hot water to flow through the pipes more slowly, and so it takes longer to get your hot water. This can be especially trying when you have long pipe runs, or when your pipe is under a concrete slab and not insulated.
Slow hot water can lead to water wastage. It can take so long to get hot water at a fixture that many hot water users let the hot water run while they do something else before returning to see if it is hot yet. By the time they come back and check they are running hot water down the drain.
At this point energy is being wasted as well as water and the energy to heat the water being run down the drain is substantial… much more expensive than the water being heated.
Tankless Water Heaters
Tankless water heaters are not water conservation friendly to begin with. It takes a tankless unit longer to deliver hot water than a storage water heater since it has to heat the water first which can take 10 to 20 seconds longer than a storage water heater would deliver it.
To obtain the hot water temperature you desire you typically mix hot and cold water to get the desired temperature. This works fine with a storage water heater but can be a problem with tankless units when lower flows are used.
To turn on the tankless heater you must draw ½ to ¾ gallons per minute, depending on the water heater model you have. The outlet temperature with a tankless unit does not change as long as you don’t exceed the maximum flow, so the minimum flow of say ½ gallon per minute is at the full outlet temperature.
If you need to mix half cold and half hot to get the desired temperature you are then forced to use 1 gallon per minute which can often be a much larger flow than you need or want. This of course results in wasted water being run down the drain.
Hot Water Demand Systems
Hot water demand systems can overcome the inconvenience of slow hot water caused by low flow fixtures. Hot water demand systems pump the water to your fixture fast without running water down the drain. Your hot water is faster and you save time water and money.
A hot water demand system typically locates a small pump under the sink furthest from the water heater. When hot water is desired the user pushes the start button which activates the pump and speeds hot water to the fixture. The cooled off hot water from the last hot water use is returned to the water heater through the cold water piping so no dedicated return line is needed.
Demand systems are especially nice when used with tankless water heaters since you save both energy, with the tankless heater and water, with the demand system while having the convenience of fast hot water.
Solar with Tankless - Water Heater Guide - Water Conservation
Friday, January 8, 2010
Water Heater Guide - What Kind Of Heater Is Best?
At first it seems like a simple question. Which water heater is the right one for my application? But after taking a second look, it can become quite complex. There are a number of ways to heat water and a variety of fuels to choose from.
Items you need to consider include the initial cost of the system, cost of operation, maintenance, physical size, fuel type, and the flow rate of hot water needed during peak usage.
Solar Water Heaters
Solar powered water heating can provide you with plenty of hot water if you live where solar radiation is plentiful. Living where freezing temperatures occur complicates systems that are susceptible to freezing.
Solar water heaters can vary in cost from very inexpensive home made batch heaters to sophisticated high tech systems with pumps and solar panels. With the more sophisticated systems maintenance and repair can become an issue.
Solar systems rarely provide a positive return on investment without some form of tax credits or other incentives because of the high initial cost and relatively small savings.
Electric Hot Water Heaters
Electric water heaters are more efficient than gas water heaters, but heating water with electricity is about twice as expensive as heating water with gas. Electricity is the most expensive way to heat water though because electricity is much more expensive than gas. Electric water heaters also take about twice as long to heat water as gas heaters take.
Electric water heaters are pretty simple devices and as a result they are quite reliable. Typically the failure mode is for a tank leak. When the tank begins to leak go find a new water heater.
Heat Pump Hot Water Heaters
Heat pump water heaters use less energy than standard because they don’t produce the heat; they transfer it from the air to the tank. It takes less energy to move the heat than to generate it. Heat pumps can use ground water to obtain heat from the earth instead of the surrounding air in some cases.
Heat pump water heaters are more expensive than traditional gas or electric water heaters, and they take longer to heat the water.
Gas Hot Water Heaters
Gas water heaters are usually the least expensive method of heating water due to the low cost of gas compared to electricity. This applies only if you happen to have access to natural gas though. There isn’t much difference between propane and natural gas water heaters other than the cost of the gas.
Like electrics, gas water heaters are fairly simple and hence very reliable. As with the electrics a tank leak is often the first sign of a problem and water heater replacement the solution.
Electric Tankless Hot Water Heaters
Electric tankless heaters are typically small due to the high amount of energy required to rapidly heat flowing water. Often they are just big enough to supply a single fixture. With electrics you don’t have to worry about venting, indoor pollution, or carbon monoxide poisoning. They are small and silent operating.
With tankless water heaters a minimum flow rate a minimum flow rate must be maintained to keep the heater turned on. You won’t be able to get a trickle of warm water.
Selecting the proper size heater for your application is critical. Too large or too small and you will have problems.
For electrics capable of supplying larger amounts of hot water will probably need their own dedicated 220 volt circuits with larger than normal wiring. You may also need to upgrade your service from your power company.
Gas Tankless Water Heaters
Gas heats water more rapidly electricity providing much larger flow rates. They can supply endless amounts of hot water, they have higher overall efficiencies than tank water heaters because there are no standby losses.
Tankless heaters require a longer delivery time for hot water, increased gas line size in and venting, and potentially higher repair costs. Most gas tankless hot water heaters will not operate during a power outage. Some models generate their own electricity from the flowing water.
Gas tankless hot water heaters are considerably more expensive than traditional storage types and should any thing go wrong they are expensive to repair. It’s also harder to find experienced service people for tankless units.
New links page. Links 5
Solar hot water combined with tankless water heating: Solar and Tankless
Items you need to consider include the initial cost of the system, cost of operation, maintenance, physical size, fuel type, and the flow rate of hot water needed during peak usage.
Solar Water Heaters
Solar powered water heating can provide you with plenty of hot water if you live where solar radiation is plentiful. Living where freezing temperatures occur complicates systems that are susceptible to freezing.
Solar water heaters can vary in cost from very inexpensive home made batch heaters to sophisticated high tech systems with pumps and solar panels. With the more sophisticated systems maintenance and repair can become an issue.
Solar systems rarely provide a positive return on investment without some form of tax credits or other incentives because of the high initial cost and relatively small savings.
Electric Hot Water Heaters
Electric water heaters are more efficient than gas water heaters, but heating water with electricity is about twice as expensive as heating water with gas. Electricity is the most expensive way to heat water though because electricity is much more expensive than gas. Electric water heaters also take about twice as long to heat water as gas heaters take.
Electric water heaters are pretty simple devices and as a result they are quite reliable. Typically the failure mode is for a tank leak. When the tank begins to leak go find a new water heater.
Heat Pump Hot Water Heaters
Heat pump water heaters use less energy than standard because they don’t produce the heat; they transfer it from the air to the tank. It takes less energy to move the heat than to generate it. Heat pumps can use ground water to obtain heat from the earth instead of the surrounding air in some cases.
Heat pump water heaters are more expensive than traditional gas or electric water heaters, and they take longer to heat the water.
Gas Hot Water Heaters
Gas water heaters are usually the least expensive method of heating water due to the low cost of gas compared to electricity. This applies only if you happen to have access to natural gas though. There isn’t much difference between propane and natural gas water heaters other than the cost of the gas.
Like electrics, gas water heaters are fairly simple and hence very reliable. As with the electrics a tank leak is often the first sign of a problem and water heater replacement the solution.
Electric Tankless Hot Water Heaters
Electric tankless heaters are typically small due to the high amount of energy required to rapidly heat flowing water. Often they are just big enough to supply a single fixture. With electrics you don’t have to worry about venting, indoor pollution, or carbon monoxide poisoning. They are small and silent operating.
With tankless water heaters a minimum flow rate a minimum flow rate must be maintained to keep the heater turned on. You won’t be able to get a trickle of warm water.
Selecting the proper size heater for your application is critical. Too large or too small and you will have problems.
For electrics capable of supplying larger amounts of hot water will probably need their own dedicated 220 volt circuits with larger than normal wiring. You may also need to upgrade your service from your power company.
Gas Tankless Water Heaters
Gas heats water more rapidly electricity providing much larger flow rates. They can supply endless amounts of hot water, they have higher overall efficiencies than tank water heaters because there are no standby losses.
Tankless heaters require a longer delivery time for hot water, increased gas line size in and venting, and potentially higher repair costs. Most gas tankless hot water heaters will not operate during a power outage. Some models generate their own electricity from the flowing water.
Gas tankless hot water heaters are considerably more expensive than traditional storage types and should any thing go wrong they are expensive to repair. It’s also harder to find experienced service people for tankless units.
New links page. Links 5
Solar hot water combined with tankless water heating: Solar and Tankless
Sunday, January 3, 2010
Hot Water – Residential Hot Water Conservation Products
Hot Water Conservation Is Harder Than Cold Water Conservation
Water conservation products for cold water conservation are prolific. There are low flow fixtures; actually these are now mandatory in most areas, low flow shower heads, water conserving appliances, low flow toilets and other flow restricting devices.
There are also things like dual-flush toilets, toilet dams, drip irrigation systems, and all sorts of other water conservation products.
A lot of these conservation devices do not really provide conservation for those individuals who are already practicing good water habits. For instance, low flow kitchen faucets only save water when someone leaves the water running based on time. Filling the sink takes the same amount of water no mater how slow the flow is. The same is true with filling a pitcher of water.
Water conserving appliances often need the user to use special cycles, which are often not used.
Most of these water conservation products do not address one of the largest wasters of water in the home… the hot water plumbing layout. Long pipe make for long delays in getting hot water. Low flow fixtures make the problem worse by slowing down the hot water.
Slow hot water loses more heat energy to the piping as it moves toward the fixture, thus the wait becomes even longer and more water gets run down the drain. So what can we do?
Water Heater Pumps
There are a class of water heater pumps known as hot water demand pumps. These are small pumps that mount under the sink furthest from your water heater. When you want hot water you demand it by pressing a start button. When you push the button it starts the pump which pumps the hot water from the water heater to your fixture at high speed.
When hot water reaches the pump, an electronic controller shuts the pump off. Now when you turn on the faucet you get instant hot water and no water was run down the drain.
The pump uses the cold water line to return the cooled down hot water that was left in the piping from the last use back to the water heater inlet. They use very little energy to operate since they run for a very short time and only when hot water is demanded by the user. Typically they consume about $2.00 per year in electricity for a family of four.
Solar Water Heaters
Demand hot water systems work fine with all types of solar systems. Some types of solar systems have longer than normal hot water distribution lines and demand hot water systems are particularly good for those types of systems. It’s not what type of fuel you use free or not, it’s how long the distribution piping and how long a wait it is before you get hot water. The longer you have to wait, the more water you are running down the drain.
Tankless Hot Water Heaters
Demand hot water pumps work great with tankless hot water heaters as long as the demand system pump has enough power to turn on the water heater. Tankless water heaters take 10 to 20 seconds longer to get hot water to the fixtures than a tank type water heater. This makes the demand system that much more valuable with tankless units.
Hot water conservation with a demand system not only provides significant water savings, but it does it in a way that adds the convenience of fast hot water. This makes it much more likely that the user will actually use it, and water conservation will actually take place.
Recent Article: Residential Hot Water Conservation
Solar hot water
Tankless water heater Installation
Hot Water Recirculation
Water conservation products for cold water conservation are prolific. There are low flow fixtures; actually these are now mandatory in most areas, low flow shower heads, water conserving appliances, low flow toilets and other flow restricting devices.
There are also things like dual-flush toilets, toilet dams, drip irrigation systems, and all sorts of other water conservation products.
A lot of these conservation devices do not really provide conservation for those individuals who are already practicing good water habits. For instance, low flow kitchen faucets only save water when someone leaves the water running based on time. Filling the sink takes the same amount of water no mater how slow the flow is. The same is true with filling a pitcher of water.
Water conserving appliances often need the user to use special cycles, which are often not used.
Most of these water conservation products do not address one of the largest wasters of water in the home… the hot water plumbing layout. Long pipe make for long delays in getting hot water. Low flow fixtures make the problem worse by slowing down the hot water.
Slow hot water loses more heat energy to the piping as it moves toward the fixture, thus the wait becomes even longer and more water gets run down the drain. So what can we do?
Water Heater Pumps
There are a class of water heater pumps known as hot water demand pumps. These are small pumps that mount under the sink furthest from your water heater. When you want hot water you demand it by pressing a start button. When you push the button it starts the pump which pumps the hot water from the water heater to your fixture at high speed.
When hot water reaches the pump, an electronic controller shuts the pump off. Now when you turn on the faucet you get instant hot water and no water was run down the drain.
The pump uses the cold water line to return the cooled down hot water that was left in the piping from the last use back to the water heater inlet. They use very little energy to operate since they run for a very short time and only when hot water is demanded by the user. Typically they consume about $2.00 per year in electricity for a family of four.
Solar Water Heaters
Demand hot water systems work fine with all types of solar systems. Some types of solar systems have longer than normal hot water distribution lines and demand hot water systems are particularly good for those types of systems. It’s not what type of fuel you use free or not, it’s how long the distribution piping and how long a wait it is before you get hot water. The longer you have to wait, the more water you are running down the drain.
Tankless Hot Water Heaters
Demand hot water pumps work great with tankless hot water heaters as long as the demand system pump has enough power to turn on the water heater. Tankless water heaters take 10 to 20 seconds longer to get hot water to the fixtures than a tank type water heater. This makes the demand system that much more valuable with tankless units.
Hot water conservation with a demand system not only provides significant water savings, but it does it in a way that adds the convenience of fast hot water. This makes it much more likely that the user will actually use it, and water conservation will actually take place.
Recent Article: Residential Hot Water Conservation
Solar hot water
Tankless water heater Installation
Hot Water Recirculation
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