Hot water on-demand systems, also known as a tankless water heaters, superheats water as it enters your home. Unlike traditional heaters that require filling a tank first, hot water on-demand heaters instantly heat the water using gas jets or electric coils. This type of water heater works exactly as it sounds. It means you get hot water exactly when needed, without waiting for a tank to fill or guessing when it will heat up.
With this, you can enjoy instant hot water for your family’s needs, making daily routines more convenient and efficient.
What is the Hot Water On-Demand System All About?
A hot water on-demand system or a tankless water heater operates without a storage tank. Instead of constantly heating and storing water, it heats water instantly as it flows through the system when a faucet is turned on. Unlike traditional tank-style water heaters, which require continuous maintenance at 120°F, tankless water heaters only heat water as needed, making them more energy-efficient. Yet, the level of energy efficiency can vary depending on a home’s water consumption.
The key feature of a hot water on-demand system is its on-demand nature, which sets it apart from conventional water heaters. This allows for more efficient energy use and provides endless hot water to the entire residence. As a result, a hot water on-demand system is becoming increasingly popular in various household settings.
Different Types of Hot Water On-Demand Systems
There are several types of on-demand hot water systems available, each tailored to your home’s specific energy and water usage requirements. Selecting the system that best matches your water needs makes the best decision for optimal efficiency.
1. Gas Tankless Water Heaters:
These systems utilize propane or natural gas combustion to heat water as it flows through the system. This category of on-demand hot water systems is divided into two classes: non-condensing and condensing.
Condensing Tankless Water Heaters:
Energy-efficient condensing tankless water heaters are designed to extract and capture heat from the unit’s exhaust. This residual exhaust heat is used to help generate hot water. Since the exhaust gases are cooler, less expensive venting materials can be utilized.
Non-Condensing On-demand Tankless Water Heaters:
Non-condensing tankless water heaters operate by consuming gas in a single heat exchanger, typically made of copper. Hydrogen serves as the fuel source, with hot fuel gases expelled as vapor through the outlet. While non-condensing systems effectively produce hot water, their efficiency typically hovers around 80%.
The exhaust from these systems reaches temperatures of around 300°F, requiring the use of expensive materials such as stainless steel or thick aluminum for the venting components due to the intense heat.
Condensing hybrid:
Condensing hybrid devices represent the third generation of hot water on-demand systems, first pioneered in the United States. These heaters integrate a small holding tank, typically between 1 liter and 2 gallons in capacity. Achieving a genuine Energy Factor (EF) of 0.92 to 0.96, these water heaters maintain a steady supply of hot water thanks to the presence of the holding tank. Consequently, they eliminate the necessity for a lower EF during quickdraws.
2. Electric Tankless Water Heaters:
Even though gas water heaters are more efficient than electric tankless water heaters in the long run, electric tankless water heaters make up by offering easier and more cost-effective installation. Electric units are generally smaller than their gas counterparts and do not require venting, which can significantly simplify installation, especially in homes lacking proper ventilation for gas heaters. Although the initial installation costs may be higher for electric heaters, they offer greater flexibility in terms of placement, often fitting into smaller or more inaccessible areas and can be conveniently located near preferred appliances.
In situations where you’re completing construction on an existing building and aiming to save time and money by avoiding the need for additional ventilation and gas lines, electric tankless hot water on-demand systems are often the preferred choice.
3. Point-Of-Use (POU) Instant Tankless Water Heaters:
Point-of-Use (POU) instant tankless water heaters are compact, electrically powered units installed as close to an outlet as possible. They rapidly heat water, eliminating the lengthy delay for hot water at the faucet and reducing wastage. They can be used either independently or in conjunction with a central water heater to enhance overall efficiency.
4. Indoor Tankless Water Heaters:
One advantage of an indoor tankless water heater is its insulation. This means it doesn’t deal with changing weather and external forces. However, condensation may still form on and around the unit. To address this, proper venting linked to a receptacle is necessary to divert this moisture away from the heater. Indoor installation requires the use of vertical or horizontal ventilation ducting to facilitate proper airflow.
5. Outdoor Tankless Water Heaters:
This water heater does not necessitate additional ventilation piping as it relies on natural airflow for ventilation. Outdoor hot water on-demand systems are designed to withstand adverse natural elements like rain, wind, and snow. However, it’s important to note that on-demand water heaters require regular care and maintenance. To prevent water from freezing in the tank, it’s essential to remember to drain the unit when temperatures drop too low.
How Does the Hot Water On-Demand System Work?
Instantaneous hot water systems operate without the need for a storage tank. Upon activating the hot tap, water flows through a heat exchanger within the heating unit. This exchanger facilitates the transfer of heat from the energy source to the water, which can be powered by either electric elements or natural gas. Consequently, there may be a brief interval of cold water flow before the hot water, typically lasting only a few seconds. Nevertheless, on-demand water heaters deliver a consistent supply of hot water.
One notable drawback of these systems is their limitation on water flow. Typically, tankless water heaters offer a flow rate ranging from 2 to 5 gallons per minute. Nonetheless, this feature is excellent for individuals with high water usage patterns, effectively reducing water consumption. Gas-powered heaters are preferable to electric ones for those seeking a higher flow rate. Remember that when hot water is simultaneously required for multiple purposes—such as in larger households—an on-demand system may struggle to meet the demand. Multiple water heaters can be installed, and specific units can be dedicated to different appliances to make sure that you will have hot water when needed.
Installation Difficulty and Upgrades to the Hot Water On-Demand System
The installation costs for hot water on-demand systems typically range from $800 to $3,500 on average. Additional installation fees may further increase the initial expense. For instance, if you need an electrician to rewire your home to accommodate an energy-hungry appliance, you may be required to pay up to $100 per hour.
Similarly, if upgrading gas lines by a home contractor is needed (which can amount to as much as $750), your upfront expenditure will encompass more than just the price of the water heater equipment and basic installation. Before moving forward with a new hot water on-demand system, consult a professional installer to determine the total cost and whether additional services are required.
Benefits of Hot Water On-Demand System
A hot water on-demand system is known for its superior efficiency compared to many traditional water heating methods. This is mainly due to its ability to deliver hot water on demand without using energy to heat unused water. Other advantages of on-demand hot water systems include:
1. Financial Savings:
Energy conservation leads to financial savings, with the amount saved dependent on factors such as the energy source of the unit, the efficiency improvement of the new water heater compared to the old one, usage frequency, and other variables. What is certain is that these savings accumulate over the years. Eventually, you could potentially save hundreds or even thousands of dollars on utility bills.
2. Space-Saving Design:
Tankless heaters have many benefits over traditional tank heaters, but they have not been widely adopted in the U.S., even though they’ve been popular in Europe for years. Tankless gas models don’t need storage tanks, so you don’t need extra room in your house or yard. They can be installed in any place with access to electricity, including inside your home, without concerns about excessive heat. Furthermore, they are easily relocatable, offering flexibility if additional space is needed in the future.
3. Low Temperatures:
If you’ve noticed that your showers are warmer than before, it’s probable that your hot water tank is gradually losing its capacity to store heated water. This can result in cooler showers and increased hot water consumption per shower. On-demand hot water systems address this issue by providing users instant access to hot water, thereby reducing the energy required to reheat cold or lukewarm water typically wasted in traditional storage tanks.
4. Energy Savings:
On-demand water heaters consume less energy compared to traditional water heaters with a tank since they only heat water as needed rather than continuously heating a whole tank. In many households, tankless water heaters can save over 30% more energy than water heaters with storage tanks.
Furthermore, hot water on-demand systems exhibit approximately 15% higher efficiency than standard water heaters in homes with high hot water consumption. Additionally, in residences where each hot water tap has its own water heater, tankless water heaters can achieve up to 50% greater efficiency.
5. Longer Lasting:
In general, the lifespan of a conventional water heater is typically 12 years, whereas tankless models usually last for 20 years or more. Furthermore, hot water on-demand systems boast replaceable components that can extend their service life even further.
Comparison Between Tankless Water Heater (Hot Water On-Demand System) and Tank-Style Water Heater
Tankless Water Heater
Tank-style water Heater
Tankless heaters are activated only when water flows through them, so they consume less energy overall.
Because a tank-style heater runs constantly, it continuously uses energy.
Tankless heaters can last up to 20 or 30 years with appropriate maintenance.
A standard, tank-style radiator lasts, on average, between 10 and 12 years.
Tankless on-demand water heater heats water only when it is required.
Tank water heaters heat and store water in advance, independent of whether a household requires hot water.
Compact design / Mounted on wall
Floor space is necessary
A tankless hot water on-demand system has a higher initial cost than a conventional tank water heater. You must also consider the price of upgrading your plumbing and electrical system.
Most portable water heaters cost more to buy at first than water heaters with tanks. An average unit costs about $250. They are also easy to put in because you don’t have to make any alterations to the plumbing or electricity.
FAQs
Where can I purchase a hot water on-demand system?
Big-box stores, Plumbing supply stores, and online retailers carry these heaters. Or order one through your plumber.
Can an on-demand water heater be too large?
They are ideal in some circumstances; therefore, it is irrelevant to discuss excessive capacity until they reach that point.
Are tankless water heaters more environmentally friendly?
Yes! Some devices are rated as efficient as 98%! They are 35-80% more efficient than conventional hot water tank heaters.
Is a tankless water heater the most appropriate option for me?
Tankless water heaters are typically most efficient in smaller homes. Most tankless water heaters can provide 2 to 5 liters of hot water per minute. If you use more than two to five liters of hot water every minute, a tankless water heater may struggle to keep up.
How long does a tankless water heater last?
Modern tankless water heaters have a 25-year lifespan. The lack of a tank, susceptible to corrosion and other unavoidable maintenance issues, nearly doubles the lifespan of a tankless variety.
Conclusion
On-demand hot water systems are gaining popularity in the United States due to their energy efficiency and compact design. Installed on the wall in utility rooms, garages, or outside homes, an on-demand tankless water heater can meet the hot water needs of an entire household, including faucets, showers, baths, dishwashers, laundry, and more.
Homeowners and property owners interested in on-demand hot water systems should thoroughly research the available options to find the one that best suits their needs. While the basic operating principle is generally the same across systems, there are numerous options, each with unique features specific to the manufacturer. Hopefully, you have familiarized yourself with hot water on-demand systems with this guide.
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