Point-of-Entry vs. Point-of Use: Which is Best for Your Home Water Treatment?

Point-of-Entry vs. Point-of Use: Which is Best for Your Home Water Treatment?

Do you know the difference between point-of-entry and point-of-use water treatment systems?

Point of entry (POE) and point of use (POU) are two different types of home water treatment systems. POE filters all incoming water, while POU only treats the water that comes out of your faucet. Which is better for your home? We’ll break down both options so you can make an informed decision about which one is best for you!

You can choose between DIY installation or hiring a professional to install either type of system. We’ll also discuss the pros and cons of both options so you can make an informed decision about which option will work best in your home. Plus, we’ve got some practical considerations like maintenance costs and space requirements that will help inform your final decision on which type is best for your needs! So read on below to learn everything you need to determine whether POE or POU is right for your home!

Point-of-Entry Systems – Whole House Water TreatmentPOE Whole House System

A point-of-entry (POE) water treatment system is used to treat all of the water where the pipe enters the house. These systems are also referred to as whole-home filtration units.

In most residential installations, there is a single POE treatment system that is designed to treat every gallon of water that is used in your home. The most popular way to install a POE system is before the water heater. This arrangement provides delivers both clean hot and cold water to every faucet and appliance in your home.

With a POE system, every drop of water you use – whether it’s for drinking, bathing, or washing your clothes – is treated and contaminant free.

POE – contaminants treated

There are many distinct types of POE systems that can treat virtually every water quality issue you may have. The type of water problem you’re having will determine the solution you choose.

The most common water quality problems people use POE treatment systems for include:

  • Hard water: caused by high levels of minerals such as calcium and magnesium that causes scale to build up on plumbing fixtures and in hot water heater
  • Chlorine: this sanitizing chemical is added to tap water and can affect taste and odor
  • Lead: this hazardous chemical is found in many older piping systems
  • Iron: this benign mineral causes staining of laundry and plumbing fixtures
  • Hydrogen sulfide: this gaseous chemical smells like rotten eggs

POE treatment systems

Treatment technologies that can be used in POE systems include:

  1. particle filtration
  2. activated carbon adsorption
  3. water softening
  4. reverse osmosis filtration
  5. ion exchange resin
  6. evaporation

Point-of-Use Systems – Treated Water Where You Need ItPOU RO system

A Point-of-Use (POU) system is used to treat only a portion of water in your house where it is used. The primary use that is treated is drinking. These POU units are installed under your kitchen sink (this is why they’re also known as “under-sink” systems).

These systems deliver clean water at your kitchen faucet and bathroom sink for drinking and cooking purposes. They don’t typically treat the water that is used for bathing, cleaning and other daily chores.

The majority of POU systems supply water via a distinct tap rather than the faucet. Although most POU filtration units are installed “under-sink”, they might also be mounted upstream of your refrigerator’s water supply.

POU – contaminants treated

Since most POU systems are installed to treat water used for drinking and cooking, the most commonly treated contaminants include:

  1. leadReverse osmosis under sink treatment system
  2. VOCs
  3. PFAS
  4. chlorine
  5. bad taste

POU treatment systems

Carbon adsorption filters are the most commonly used treatment system for POU applications. Primarily, these units are installed to remove taste and odor from water.

In addition, to activated carbon, POU treatment units can include many other technologies. These include:

POE and POU are two different approaches used to treat contaminated water in your house. Each method removes contaminants from your water, they just treat it in different locations and purposes.

There are many different types of treatments available, each with its own set of benefits. Some may be used together to help tackle a range of water quality concerns.

In the next section, we review the Pros and Cons of POE and POU treatment.

Pros and Cons of POE Water Treatment System

POE treatment is installed at the location where water enters your home. Every drop of water is treated throughout the entire building. In this method, all of the water you use is purified, regardless of where you get it or what you use it for.

Since a POE unit treats all of the water you use, they are larger than a POU system. A typical POE system is designed to treat several thousand gallons per day.

Advantages and benefits of POE systems

There are many advantages to treating all of your water. These include:

  1. Convenience: having a single treatment system that is centrally located is much simpler to maintain and inspect compared to one or more devices installed under sinks and in closets.
  2. Lower lifetime costs: although the initial purchase and installation is more expensive, a single unit can often be cheaper to maintain than multiple POE devices.
  3. Easier maintenance: POE systems are much larger than under-sink devices, so they often require less frequent filter replacements (some last 4 to 6 years). In addition, access is better for a unit located in your basement compared to an under-sink filter.
  4. More rugged construction: the larger equipment is typically better made than the small units designed to fit in tight spaces.
  5. Pure water, everywhere: a POE system provides purified water everywhere, for any purposes, rather than just at the kitchen sink.

Disadvantages and limitations of POE systems

A whole house treatment system also has some undesirable attributes. These include:Professional installation

  1. Higher cost: the purchase price and cost of installation is greater for a POE system
  2. Requires professional installation: many whole house systems typically require a plumber to install because your water pipes have to be cut and then reconnected to the unit. This is a negative for DIY folks.
  3. Treatment limitations: for some contaminants a POE system may not work as well. For example, lead and copper often leach out of piping and plumbing fixtures which are downstream from a POE treatment unit.
  4. Undesirable side-effects: reverse osmosis units produce “aggressive water” due to low dissolved solids which can damage pipes and fixtures.
  5. Waste generation: RO units waste some percentage of water as part of their unique filtration process. Carbon and particulate filters must be disposed of. A whole house system produces a lot more waste than a POE unit.

Pros and Cons of POU Water Treatment System

POU requires installing water treatment units at every location where the water is used.  Generally, you only treat water used for drinking and cooking. In this approach, water used for showering and washing laundry is not treated.

Advantages and benefits of POU systems

Under-sink treatment systems offer several advantages compared to whole house treatment.

  1. Cheaper: POU systems are generally cheaper than POE treatment. This is because they are smaller compared to a whole house system.
  2. Better water quality: point-of-use filters can be “over designed” because of their smaller size whereas a whole house system doesn’t.
  3. Smaller: POU treatment units are typically smaller than whole house devices, so they can fit under sinks or on countertops.
  4. Accessibility: POU systems are generally very compact and conveniently located in your kitchen or bathroom
  5. Easier installation: many POU systems do not require a plumber for installation. They are designed to be DIY friendly.
  6. More versatile: because each sink has its own treatment unit, you can choose the type of water treatment that is best suited for that application (e.g., activated carbon filter for removing chlorine from drinking water).

Disadvantages and limitations of POU systems

A POU system presents several drawbacks compared to POE systems.

  1. More frequent maintenance: the smaller POU systems require more frequent filter changes.
  2. Low volume: a typical POU RO filter only produces 40 gallons per day which limits the amount of water you can use.
  3. Slow treatment: the flow of water coming out of an RO unit is a trickle if you don’t have a storage tank for treated water.
  4. Quality issues: some POU filters are made of light duty components that may not hold up over time.

Factors to Consider When Deciding Between POE and POU

When deciding between a whole house or under-sink water treatment system, there are several factors you should think about. We discuss the most important considerations in the following section.

1 – Cost considerations for POE and POU systems

If you have a limited budget, an under-sink treatment system will be more affordable. They cost less and many can be installed without professional help.

However, the filter cost for POU systems can be high over time because they only last a few months. A POE system might only need to have the filters replaced once a year – although the cost per filter is higher because of their greater size.

2 – Maintenance of POE vs POU systems

Maintenance is an important part of any home water treatment system. Filters must be changed and worn parts must be replaced.

Under-sink filters can be difficult to reach because everything is smaller and crammed into your cabinet. Fixing leaks can also be difficult on a POU unit.

A whole house unit is typically installed in an area with good access and is designed to be serviced. You’ll find that being able to comfortably work on your filter makes servicing your unit much easier.

3 – Water usage needs

Point-of use systems are best suited for low volume applications where the water is used only for drinking or cooking purposes. They may not work well in high-volume applications such as showering and washing clothes.

A whole house system can handle a high volume of water usage. If you have a large family with multiple people using the water for different purposes, a whole-house treatment system may be the best option.

If you are single or live in a small household, a point-of use system is likely to meet your needs.

4 – Contaminant specific concerns and approaches

The type of problem your treating may help you deciding between a large, whole house system and a POU unit.

For example, if you have lead in your water, you may want a POU system because lead leaches out of the pipes and fixtures in your house. If you treat the water where it enters your home, you might still have lead in your water by the time it reaches the faucet.

If your problem is scaling, you probably want a whole house system to protect all of your pipes. Otherwise, you may end up plugged pipes in part of your house.

5 – Performance of POU vs POE water treatment systems

If you want the purest water for drinking, you might be better off with an under-sink treatment system. A high-quality RO filter can remove all contaminants and deliver pure water for drinking and cooking.

6 – DIY vs professional installation for POE and POU treatment units

Most homeowners can install an under-sink water treatment unit on their own. All you need is a screwdriver, wrench and pliers.

Whole house systems require professional installation unless you are familiar with plumbing and electrical work. A whole system typically costs more to install than an under-sink POU system, but the long-term savings may be worth it.

7 – Space considerations for POU vs POE water treatment

Space is a consideration with both types of water treatment systems. If you purchase an under-sink water treatment unit, you need to be sure you have enough room for the filter, storage tank and plumbing connections before purchasing your system. You also need enough space to access the filters when it’s time to change them.

A whole house POE system also requires an assessment of the available space. These units are larger than the under-sink type, and they need enough space for the pre-filter, media tanks, additional plumbing, and other components. You also want to give yourself enough space to access the various components so that you can easily perform the periodic maintenance.

8 – Treatment specific considerations

Depending on the water quality issued your addressing, you need to consider the type of water treatment system that will work best for your home.

If you have hard water, a whole-house filter with an automatic backwash may be the best option. If you have bacteria or viruses in your water, you’ll need a disinfection system such as chlorine or ultraviolet light. These systems usually are better suited for a whole house application.

A reverse osmosis unit is good for removing contaminants like lead, arsenic and fluoride from your water. An under-sink RO unit is often preferred because the aggressive water can cause corrosion of copper pipes in your house.

In general, whole-house systems are better at addressing multiple problems while POU systems are more tailored to a specific need. Do some research to find the best system for your specific water quality issues.

9 – Sustainability concerns for POU and POE water treatment systems

Both POU and POE water treatment systems come with sustainable options, but whole-house filters use are less sustainable than under-sink units.

RO filters waste some amount of water – this is an inherent part of the treatment process. A whole house RO filter will waste a lot more water than an under-sink unit.

If you are using activated carbon, the spent media is a waste byproduct that must be disposed of. A POE filter will require a lot more carbon than a POU filter.

10 – Increasing your home’s value

Installing a water treatment system in your home will add to its value. Even if you don’t need the system right away, it’s a great investment that will help your home retain its value.

Whole house water treatment systems are larger and more expensive than an under-sink POU filter. They provide longer lasting benefits like protecting all of your pipes from scale buildup and corrosion though, which is why they may be worth the extra cost.

POU water treatment systems are smaller and less expensive than whole house filters, but they only provide benefits to specific fixtures like your kitchen faucet or bathroom sink.

Either approach will increase your home’s value and deciding between POE versus POU will come down to your specific needs and the space you have available.

Hybrid Approaches – Using Both POE and POU Treatment Systems

As we’ve discussed, POE and POU systems can be used to effectively treat your home’s water. There are situations where one approach is better than another, and vice versa.

You may find that using both strategies – a whole house and POU treatment approach, works best for your situation. For example, you could use a whole-house water softener with a pre-filter to remove sediment and hardness from your water. This will provide general benefits to all of your fixtures and appliances. You can then supplement this system with a POU reverse osmosis unit that specifically targets lead, arsenic and fluoride removal.

This hybrid approach gives you the benefits of both systems and can be tailored to meet your specific needs. Talk to a water treatment professional to see if this is the best option for you.

My Take on POE versus POU Water Treatment

Point-of-entry verses point-of-use water treatment systems have been around for a long time, and there is some debate over which one is better.

Picking the right water treatment system for your home can be a difficult task. There are many factors to consider, including budget, water quality needs, and family usage patterns.

This article has gone over two major methods of treating your tap water—point-of-entry systems that treat all incoming cold or hot water at the main point of entry into the house before it’s distributed throughout the plumbing lines; and point-of-use systems where you install an additional unit on one faucet in each bathroom sink. I hope this information helps you make an informed decision about which type of system is best for you!

Chief Guru

Richard Boch is a chemical engineer responsible for designing water filtration systems for industrial and residential customers. He has more than 20 years of experience with ion exchange, activated carbon, and reverse osmosis. Richard's expertise has made him a go-to source for municipalities and businesses looking to improve their water quality. When he's not working, Richard enjoys spending time with his wife and two young children. You can also follow him on LinkedIn, Twitter and Facebook.

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