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BEST WATER HEATER BUYING GUIDE – TANKLESS VS TANK HEATERS ?

TANK TYPE WATER HEATER

Depending on the size of your family, you may consider the storage capacity of tank type water heaters. Such devices are provided with insulated tanks in which water is heated and stored for use. It is the commonest kind of heater that is used for commercial as well as residential purposes. Such products are classified as electric, natural gas, liquid propane devices.

When choosing such water heaters, you need to consider the size of the tank because these are categorized by the gallons of water that can be stored within. To know the ideal size of the tank type water heater, you can take guidance from the following chart:

Family size

Electric

Liquid Propane/Natural Gas

Minimum Gallon Recommendation

Over 5 members

80

50

3 – 4 members

50

40

2 – 3 members

40

40

1 – 2 members

30

30

A second factor that needs consideration is the recovery rate, which is defined by the number of gallons that can be heated in an hour. A simple rule is that households that have greater requirement for hot water will require higher recovery rate heaters. Users must also check the annual operational costs energy efficiency information that is available on the Energy Label guide.

How storage tank water heaters work
The operation of these water heaters follows the principle of releasing hot water from the top of the tank when you turn on the hot water tap. The hot water used is replaced by cold water from the bottom of the tank ensuring it is full at all times. A thermostat opens the valve as the temperature of the water decreases. This valve closes when the water temperature increases to the set point of the thermostat.

Advantages
The foremost benefit of such water heaters is their capability of storing more amount of heated water at all times. These products are available with capacities ranging from 20 gallons to 100 gallons.

  • The next benefit of tank water heaters is the energy usage at relatively lower rates. These tanks heat the water gradually thereby consuming less power. In addition, the heated water is stored under thermostat-monitoring. In other words, if hot water needs to be reheated, it is done at the right temperature to reduce energy consumption.
  • Tank type heaters have the advantage of providing constant temperature in the longer period, which is highly beneficial while bathing under the shower. You can enjoy a luxurious shower with steady supply of water heated at the right temperature for maximum comfort. There are no surprising cold water spurts because the system continuously monitors the temperature of the water.
  • These water heaters heat cold water and store it for usage as needed through a pipeline. Because the tanks have large holding capabilities, owners are able to simultaneously enjoy hot water in multiple outlets.
  • The thermostat heats the water at periodic intervals. The possibility of frozen pipes is eliminated because the thermostat automatically adjusts when the temperature falls below a certain level.

Disadvantages

The above-mentioned benefits are primarily associated with the storage tanks and thermostat. However, these two factors are also the biggest disadvantages of these water heaters. The constant heating of the water requires higher consumption of energy resulting in more expenses. Often when the hot water is not used, this cost is wasted and is known as standby heat loss. This loss can be minimized by ensuring proper insulation of the storage tanks.

Another disadvantage is the large requirement of space needed to fit the storage tank. This could be problematic especially for those who reside in condos or small homes. Sometimes, the insulated heaters become very hot and emit heat making it almost impossible to fit these inside the homes.

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The traditional electric tank type water heater needs two heating components. Each of these elements comes with its own thermostat. One component is located at the storage tank’s base and is primarily designed for sustaining the minimum temperature settings. The second component is found on the top of the tank. The primary design is for providing the recovery of hot water when the requirement for the hot water increases. These tank type electric heaters can contain between 20 and 80 gallons of water that remains hot at all times.

Also known as heat pump water heaters, these extract heat from air and deliver this to the water. These can either be stand-alone systems or combination heating systems. The electricity is used to transmit heat from one location to another, which makes these two to three times more efficient than conventional electric resistance heaters. Installing these heaters must be in a place where the temperature is maintained between 40 degrees and 90 degrees Fahrenheit around the year. Additionally, at least 1000 cubic feet air space is needed around the heater. The cool exhaust air must be removed to the outdoors or the room.

When you decide to procure and Energy Star certified electric storage water heater, you will invest in a fuel efficient system. You will require using less than fifty percent of the energy used by the standard electric storage water heaters. Studies show that households can save up to three hundred and thirty dollars per year if they opt for these rated heaters. This means an Energy Star saver heater will save a four-member household almost $3500 during its life, which will pay the additional cost within two years. Let’s look at the numbers in the table below to understand better.

Household size

Annual savings ($)

Payback period (years)

Lifetime savings ($)

Assumed: Electricity rate @12 cents per kWh and incremental cost $800 with 13 years lifespan

2

170

4.8

1360

3

250

3.2

2430

4

330

2.4

3510

5

410

1.9

4590

6

500

1.6

5670

Advantages

  • Safety – Compared to gas-fired water heaters, the electric water heaters have several benefits. One of these includes higher safety because the combustion process of the gas heaters is eliminated by such products.
  • Convenient and simple – These devices are very easy and simple to install and operate. Electric water heaters are the most convenient and simplest products for both commercial as well as residential purposes.
  • Functionality and efficiency – The fuel fired products are less functional with lower efficiencies making the electric heaters more appropriate for usage.
  • Operational costs – It is common for most people to believe the cost of using electric water heaters is higher than gas or liquid propane heaters. However, when you consider the higher efficiencies offered by the former products, the costs actually are lower. Factoring different parameters, such as design, maintenance, installation, effects on space conditioning loads, and lifespan, the electric water heaters are better in terms of operational costs.
  • Standby losses – Since these water heaters are better insulated, the standby loss factor is much lower than other devices. Typically, these products lose approximately one percent per hour. If the need for hot water is less, the cost can actually be lower than other kinds of water heaters.
  • Easy availability – Gas may not be available in all locations; however, electricity is available almost everywhere. Therefore, opting for electric water heaters ensures you receive reliable and constant flow of water supply.
  • Lower maintenance – The fuel-fired heaters need higher maintenance because these are more complex and undergo the combustion procedure. Additionally, the flues and burners corrode over a period of time and face mechanical damages. All these maintenance costs and damages are avoidable with electric water heaters resulting in lesser expenses.

Disadvantages

  • Although the electric water heaters provide regular and reliable supply, there are many limitations of these products. While considering energy efficiency and sustainability the conventional water type tank electric water heaters are not appropriate except as a boosting system.
  • In addition, these devices are not as energy efficient as the heat or solar water heaters. These use electricity generated from fossil fuels, which result in the emission of dangerous greenhouse gases making these water heaters harmful to the environment.
  • As the cost of electricity continues to increase, homeowners are trying to find cost and energy efficient alternatives to reduce their expenses.

Gas Tank Water Heater

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Gas water heaters are available in different shapes and sizes in unique designs and wide range of colors. These devices have numerous basic systems that make them functional. These systems include the water tank, heating elements, water intake/output, and safety systems. The advanced level and sophistication of the safety controls and systems primarily depends on the age of the gas heaters.

Understanding the working

  • The cold water is pumped within the tank or reservoir
  • The heater at the tank’s bottom is turned on
  • The hot water rises to the top
  • Cold water is circulated at the bottom where heated
  • The heated water is pulled from the top to the supply outlet

The Tank

Over the years, technical improvements have resulted in making the storage tanks efficient to store the hot water. The need for reheating the water to maintain the temperature reduces as the efficiency of the tanks improves. However, the tank can be the greatest constraint especially for homes that need plenty of hot water. If your home runs out of hot water quickly, you should replace the storage tank to a larger capacity. Alternatively, you must find faster recovery rate or turn the thermostat up to heat the water quicker.

Heating element
The gas water heaters use burners beneath the tank for heating the water. Natural or propane gas is piped to these burners to light them up (similar to gas stoves) to heat the water. A temperature regulator comprising switch and thermostat connected to the gas burner are beneficial in controlling the amount of gas that is burned. As the amount of gas increases, the water becomes hotter.

Heater intake/output
This is a simple system comprising two water pipes that run inside the gas water heaters. The one located at the bottom or close to the bottom is the cold water intake and directly feeds through cold water line into the base to heat the water. Located near the top or at the top is the hot water output, which pumps the water to the various outlets in your home.

Safety systems
This is again based on the age of the water heater. Most of the newer gas water heaters provide several automated and passive safety mechanisms. The passive systems are important in the event that the heaters lose electricity without losing gas. These systems prevent the water from heating to dangerous temperatures. The passive safety mechanism involves pressure relief valve. In case the pressure increases to high levels, it is relieved through the opening of the valve thereby releasing steam and water. Excessive pressure build up could be due to excess heating of the water or higher pressure in the supply of the cold water. The automated safety mechanisms use thermostat to shut the gas when the heating level for the water reaches the required level. The thermostat connects to the heating elements.

Capacities
Although capacity refers to the size of the storage tank, it is the result of two factors; the recovery time and storage. The tanks are available in different sizes ranging from 20 gallons to 120 gallons; the commonest used being 40 to 80 gallons. A few short models in smaller sizes are also available. Matching the size of the tank to your family size is very important. Smaller tank may result in quicker cooling of the water while unrequired larger sizes will result in your incurring higher expenses than necessary.

Considering the number of bathrooms in your home is also important. Certain factors like a home with kids needing plenty of laundry, a large family, or homes with a large bathtub can skew this factor. Below is an indicative table listing the storage tank capacity:

No. of bathrooms

Capacity

1

40 gallons

1.5

40 gallons

2.5 - 3.5

50 gallons

4

75 gallons

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The recovery for gas fired water heaters is the function of BTU input and the overall efficiency. The input ranges from approximately 32000 on 30-gallons unit to 88000 on roughly 100-gallons tank. The common input is 34000 BTUs in a 40-gallon storage tank and 36000 BTUs with 50-gallon tank. With higher BTU efficiency and input will provide faster recovery.

Benefits

  • Excellent for recovery
  • Homes with large bathtubs can enjoy quicker filling of their tubs because gas water heaters become hotter faster when compared to the electric water heaters
  • Longer lifespan of roughly seven to eight years
  • Fewer greenhouse gas emissions making these environmentally safer
  • The continuous gas-flow mechanisms with high efficiency storage tanks are more efficient
  • Sustainable as does not use fossil fuel for operating
  • Lower operational costs
  • Not affected by power outage providing reliable and continuous supply of hot water

Disadvantages

  • Initial higher investments due to greater costs
  • Requires ventilation in the outdoors for safety
  • Greater heat losses as heat is lost in the combustion exhaust. However, condensing gas burners will reduce the heat losses by a significant level
  • Sometimes gas may be unavailable through reticulated mechanism, which requires the use of gas bottles that can make it costly for operating
  • When gas is available through the reticulated mechanism, users may need to pay additional connection and supply line charges

TANKLESS WATER HEATER

The objective of tankless water heaters is to heat the water as required instead of constantly heating it in a storage tank. For homes that can use these products, the possible annual savings in their expenses can be significant. These systems are available in two varieties; whole house and point of use heaters.
The point of use products are smaller and heat water only for one or two outlets. Since these are small, they can be easily fitted in a closet or under the cabinets. Water loss can be avoided because these are fitted close to the outlet due to lesser lag time. On the other hand the whole house heaters are bigger, costlier, and can provide hot water to more than one outlet simultaneously. Users can choose from electric, propane, and natural gas tankless water heaters. The decision depends on two factors; flow rate and temperature rise. The flow rate is the amount of hot water required at a point in time. The temperature rise is the difference between desired output and ground water temperatures.

Benefits

  • Longer lifespan of five to ten years more than the tank water heaters
  • Need lesser space for installation making it an excellent choice for small apartments and homes
  • Unlimited supply of hot water for added comfort and convenience
  • More efficient with almost no standby losses
  • Energy requirement is limited to the amount of water that needs to be heated for any one point of use
  • Savings of about 25% to 50% on the electricity bill
  • With electric tankless heaters, ecological damage due to greenhouse gases is eliminated
  • No flooding due to ruptured tanks
  • Easily replaceable parts and affordable

Disadvantages

  • Significantly more expensive than all other types of water heaters that are available in the market; almost three times more than the tank water heaters
  • Expensive upgrades become necessary to the natural gas lines and the need for costly venting systems
  • Hot water outputs needs to be split among the different household fixtures
  • Additional circuit requirements for electric products
  • Annual servicing costs needed for gas powered water heaters
  • Minimum need of 0.5 GPM for activating the heat exchanger
  • Lag time may result in wastage of water
  • Size – Before you decide to procure one of the numerous water heaters, considering the maximum temperature and the flow rate of the various fixtures is very important. You want to ensure the water heater appropriately meets all the needs of your household.
  • Fuel type – The source of energy you utilize to operate the tankless water heater plays a crucial role in the efficiency and operating costs. Taking into consideration these two factors before making your choice is crucial.
  • Costs – Almost every person considers the price while contemplating any kind of water heater. He or she needs to ensure the product is purchased at the lowest possible price without compromising on the quality.

FACTORS TO CHOOSE TANKLESS WATER HEATERS

Choosing an experienced and reputed professional to install the water heaters is advisable. Regularly inspecting the heater to ensure it is functioning smoothly and maximum efficiency will prolong the lifespan of your water heater.

TANK VS TANKLESS WATER HEATERS

Comparision of Tank heaters with Tankless Water Heaters

Type

TANK WATER HEATER

TANKLESS WATER HEATER

Size

Very big and bulky because of tank

Most are the size of a small suitcase

Electricity

24X7 standby electricity use

As needed use, this saves over 40% over tank heater

Water

Supply limited to the size of the unit

Unlimited hot water supply

Altitude

Many heaters upto 10,000 ft with chip

Many heaters upto 9,600 ft with chip

Energy

Most gas heaters are energy start approved while most electric are not

Most Energy Star approved

Cost

Low upfront,
high over lifetime

High upfront,
Low over lifetime

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Determining the kind of water heater

With the increasing price of electricity and the awareness on reducing the ecological footprint, most people thing gas based water heaters are better. Although, prima facie this may seem accurate, there are other factors that often negate or neutralize the available benefits.

Duration of stay
When you compare either a gas or electric tankless water heater with the conventional tank type product, there is no doubt of significant savings. On an average, you will be able to save between 35% and 45% per month on the utility bill. However, the initial cost of the tankless product is 3 to 5 times higher than the traditional storage devices. Nonetheless, it may still be advantageous because the additional initial outflow can be easily recovered within 3 to 6 years from the time of installation.

If you plan to live in the home for many years, choosing the tankless water heater is more appropriate. However, if the duration of your stay is going to be only one or two years, opting for the conventional storage tank water heaters is recommended. But, installing energy saving water heaters in the house will increase the potential price you may be able to get when you decide to sell it. Choosing gas water heaters simply because it is cleaner with higher energy efficiency is advisable. When you add the significant savings over the conventional products justifies incurring the additional 20% price you will need to pay for the gas water heaters.

Johnny's Plumbing and Hydronics has installed many thousands of water heaters and tankless water heaters since 1978. If you are located in the Southern Colorado region and need assistance with the installation of a new water heater, give Johnny's Plumbing and Hydronics in Cañon City, Colorado 81212 a call today at 719-269-1252.