What is the Difference Between Low Flow and High-Efficiency Toilets?

Flush… Flush… Flush… Every time you or a family member uses the old toilet in your home you are wasting large amounts of water that could otherwise be saved.

With the onset of droughts around the world, saving water is becoming more and more of a concern for millions of people around the world.

What is the difference between low flow and high-efficiency toilets?

Low flow toilets are solely concentrated on flushing using the least amount of water. High-efficiency toilets are also concerned with using the least amount of water but doing so in the most efficient and effective way possible. High-Efficiency toilets are low flow toilets that actually flush effectively.

There are different types of low flow and high-efficiency toilets and they all save money and water at different rates. Have a read through to find out which works best for your bathroom needs.

What are Low Flow Toilets?

Low flow is how rappers refer to expensive toilets… Sorry…… back to reality. Low flow toilets are like regular toilets that use 20 to 60 percent less water than their regular counterparts. They were first introduced around the 80’s and 90’s in an effort to conserve water per household.

In 1994 the U.S. government passed a federal law that all manufacturers must comply with a new low flow standard for how much water can be used during every flush, which was 1.6 gallons per flush (gpf).

This was in an era when most toilets used an average of 3.4 gpf. Unfortunately, at the time engineers failed to also make toilets more efficient and able to flush waste down properly.

What are High-Efficiency Toilets?

High-efficiency toilets are similar to regular low flow toilets in that they use less water per flush.

The only difference is high-efficiency toilets are designed to both conserve water per flush and, using modern technology, work efficiently without fault.

High Efficiency Toilet?

Types of High-Efficiency Toilets

There are two main ways in which toilets work.

The most common design found in most homes are the gravity flush toilets. These toilets are manufactured to use a quantity of water sufficient to flush away solid waste.

When the toilet is flushed, the opening of a valve allows the water in the tank to drain which passes a siphon jet. With the force of the water now pushing the waste outward the toilet clears and is ready for another use.

These models have been less effective in the past but with modern designs and engineering, they are able to effectively get rid of waste without exceeding the allowed 1.6 gpf. They are also relatively cheap and easy to manage as the replacement parts are common and easy to work with.

Gravity flush toilets have two alternative categories, including the one time or single flush and dual flush toilets.

Single flush toilets use the permitted 1.6 gallons of water for every flush and with new designs work well to remove the necessary threshold of 250 grams of waste. These use the gravity flush system when getting rid of waste.

Next are the common and increasingly more popular dual flush toilets. You have probably seen these in modern homes because the two half mooned flush handles or buttons are hard to miss. These are great because the large flush uses 1.6 gallons of water to effectively get rid of waste and the smaller flush option uses only 0.8 gallons per flush suitable for flushing urine only visits. Thus allowing you to control how much water you want to use on every flush.

The second model is the high pressure assisted toilet. You know those scary-sounding toilets in airplanes and hotels that suck the air out of the entire room and flush like there is no tomorrow? You know what I’m talking about. Those are pressure assisted toilets.

These models compress air within a tank using the pressure of the water poured into the toilet. When flushed a fast whoosh, ergo the sound, of pressurized water forces waste out of the bowl and through the drainpipe.

They are mostly used for commercial purposes but can be installed in homes as well. You just have to cope with the loud noise it makes after every flush.

These models are also fairly expensive and more costly to fix or repair. Unfortunately, you can’t integrate this design into the existing model in your bathroom, so think long and hard before you choose which high-efficiency toilet you go with.

Do Low Flow Toilets Clog More?

Based on the initially failed approaches of low flow toilets and being that they were prone to clogs, both consumers and manufacturer’s started to cheat the system.

Most homes rejected the idea of buying a new toilet because of reports on how terrible the new models worked, so they just stuck to the toilets they already had installed in their homes. That’s why you will often see numbers like 1990 and 1993 printed on the back of toilets.

Similarly, manufacturers exploited the system by undercutting the law and created toilets that used more than the allowed limit of 1.6 gpf. It wasn’t until a man named Gauley began testing toilets and found out that the low flow toilets were actually using much more water than they were supposed to.

Gauley established the acceptable threshold that low flow toilets should easily dispose of 250 grams of waste, double the average “deposit” so to speak. It was his work that pushed manufacturers to create toilets that worked more efficiently.

So we can thank Gauley for this article.

Fortunately, today most low flow toilets can handle upwards of 500 and 1000+ grams of waste. Because of high competition and a new overall market standard, clogs for new models are rare and uncommon.

Big Button for No. 2’s and Small Button for a Quick Dash

How Much Will You Save?

Your toilet uses the most water out of all the appliances in your home so getting a model that can save up to 60% water per flush is a huge plus!

Before you rush out and get a new toilet you should first check to see whether your toilet is an old model or has an integrated dual flush system. If you see the year 1994 printed on the toilet it’s probably a good idea to invest in a new toilet system.

Now, let’s look at some numbers.

By calculating how much a new toilet costs and how much water it uses in comparison to older models, we can get a good understanding as to how much money a low flow and high-efficiency toilet can save and at what point can you get your money back.

The old low flow models that use less water but also don’t work with large amounts of waste are probably going to set you back. Most of these older failed designs require more than one flush and clog easily and often, defeating the entire purpose behind a low flow toilet.

Instead, let’s focus on low flow but high-efficiency toilets.

The average person will flush the toilet four to six times a day which with older models using 3.5 gpf translates to around 18 gallons of water being used a day. Multiply that by four and you have the daily toilet water usage of your family.

Do you see why the toilet is the most wasteful appliance in a home?

Just by switching to a low flow single flush toilet a family of four would save 14,000 gallons of water per year! This translates to about $100 to $250 of savings every year based on where you live.

A dual flush toilet has even greater savings! This model will save around 4500 to 5000 gallons of water per person every year, that’s around 1000 to 1800 gallons more than the single flush toilet. Some models will save upwards of $1000 in around 8 to 10 years, so you are definitely getting your money’s worth here.

The average low flow toilets cost around $200 and goes up to $500 with labor fees. Minus the cost of water, which is around $2 per 1000 gallons flushed, you could get a return on your investment in less than two years and a nice clean modern & comfortable toilet too!

If you’re looking to update your home and have a smarter and more energy efficient bathroom you should definitely start with replacing your toilet. The most cost-effective replacement is a high-efficiency dual flush design that can handle 500+ grams of waste.