Food Waste Disposer

Garbage Disposals for Disposing Food Waste in the Kitchen

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Home Food Waste Disposer

By Recycling.com/ 13 May 2019 Shares

Guide for Garbage Disposals

Grind Biodegradable Food Scraps & Flush It Down The Drain

Home Use
Garbage Disposal

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Commercial Use
Garbage Disposal

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More about Food Waste Disposers

What to do with food scraps in your kitchen at home or office canteen? You can throw the food waste away in a trash can or you can compost the scraps in a composting bin. But you can also grind your biodegradable food waste up right under your sink with a garbage disposal unit and wash the particles away down the drain. A kitchen waste disposal unit is an easy, convenient and eco-friendly solution to dispose food waste in your kitchen at home, in the office or commercial environment such as a restaurant. In the U.S. 50 percent of all homes have a waste disposal in the kitchen installed.

kitchen-sink-food-scraps-garbage-disposal-flush-away
Flush away food scraps down the drain.

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Which garbage disposal for food waste and scraps do you need? Let’s find out in this buying guide.

What is a garbage disposal?

A garbage disposal unit is an electronic device that is installed inside a kitchen cabinet between the sink drain and the drain pipe. Biodegradable food scraps are fed into the disposer through the drain opening. The disposal unit contains a rotating grinding plate which grinds and shreds food waste into small particles. The food remains are then flushed away with (cold) water into your sewage system. Optionally you can connect a dishwasher hose to the discharge of the garbage disposal unit.

The pros and cons of a food waste incinerator

Pros:

  • Reduce the volume of food waste.
  • Convenient and hygienic way of disposing food scraps.
  • Relatively easy to install under most kitchen sinks.
  • It keeps food scraps away from landfills.
  • Your trash can doesn’t smell bad anymore.
  • Requires minimal energy (3-4 KWh a year / 50¢ a year).

Cons:

  • Composting food scraps is more eco-friendly.
  • Some garbage disposers can make quite some noise.
  • Not every disposer unit might fit your kitchen cabinet.
  • After a while a garbage disposal can have a bad odor because of bacteria.
  • Some disposers can’t grind and process stringy or fibrous food scraps.
  • A food scrap disposal can jam, overheat or leak water.
  • It is possible that drain pipes get clogged.
  • Some disposers require extra parts for installation which are not included.
  • A continuous feed garbage disposal requires approximately one gallon of water a day.
  • Not recommended when you make use of a septic tank.
  • Waste water treatment is more difficult because of the food waste particles.

A garbage disposal is also known as a food waste incinerator. And in Canada this device is called a garburator.

How much does it cost?

The price of a food waste disposer depends on a few factors, such as:

  • The power of the motor (HP & RPM).
  • The capacity of the unit.
  • The amount of grind stages.
  • The built quality.
  • The type of garbage disposal.
  • The brand of the garbage disposal.
  • The number of operators.
  • Additional accessories, tools and parts needed for installation.

More power means a higher price

Generally you can divide garbage disposal units into four categories:

  • Light use at home (1/3 HP): $75-100
  • Medium use at home (1/2 – 3/4 HP): $100-150
  • Heavy use at home or office (1 HP): $150-500
  • Commercial use for professionals (5+ HP): $2,500+

As you can see above, professional garbage disposals are much more expensive than food disposers you use at home. That is because for commercial or industrial use the machine needs to be very powerful to process high volumes of food scraps and biodegradable kitchen waste continuously compared to a kitchen incinerator for home use.

Comparison of home & office disposal prices

Motor Avg. Price Avg. RPM Class Users Usage Food Waste Examples
1/3 HP $84 1970 Very weak 1 - 2 users Light-duty Soft food Fruit rinds
1/2 HP $112 2070 Weak 2 - 3 users Medium-duty Scraps & leftovers Potato peels
3/4 HP $145 2310 Average 3 - 4 users Medium-duty Tough scraps Small bones
1+ HP $283 2525 Powerful 4 - 8 users Heavy-duty All food scraps Fibrous foods

Price comparison between popular brands

Below you can see a comparison between three popular brands for garbage disposals: InSinkErator, Waste King and Moen. We have compared multiple disposers, calculated the average price and compared this with the power of the engine in HP.

garbage-disposal-price-compared-to-hp

How does a food waste incinerator work?

A garbage disposer doesn’t work the same way as a paper shredder, blender or a food processor. This means that a disposer doesn’t shred and chop the food scraps with sharp cutting blades. A garbage disposal rather grinds food scraps with a plate or grinder wheel. The wheel is equipped with pointy impellers or lugs and spins around very fast which causes a centrifugal force. When biodegradable food waste is fed inside the unit the wheel grinds up the food that is forced against a stationary grinder ring. The remaining food particles are then washed away down the drain with, preferably, cold water.

The use of cold water is recommended to prevent possible clogging due to solid fats.

Video: How does a InSinkErator garbage disposal works?

Video: What happens inside a food waste disposer?

Will grinded food waste clog the drain pipes?

A garbage disposal will not clog your drain pipes when used properly. But a jammed up disposal unit or clogged drain pipe can happen of course. Here are a few reasons why your drain pipes can clog. It can clog because:

  • Fat, grease or oil was disposed with warm or hot water which congeal inside the drain pipes.
  • Hard, stringy or fibrous food waste was fed which couldn’t be processed well and jams up the drain pipes.
  • Little water was used to wash the food waste particles away which causes a jammed up drain pipe.

Garbage disposal types: Continuous feed & Batch feed

There are two types of garbage disposal systems, continuous feed and batch feed.What are the differences and pros and cons between these two types. And which one suits your needs best?

continuous-feed-vs-batch-feed-garbage-disposal

Continuous feed

  • The food waste incinerator keeps running as long as you want. This is especially convenient when you are cleaning the kitchen and continuously want to dispose food scraps during the cleaning process.
  • A continuous feed is less expensive to buy in comparison with a similar batch feed incinerator.
  • You need to run water when processing and washing away the food scraps. On average you use around one gallon of water per day.
  • You can feed food waste inside the food scrap disposer when it is running. Therefore it is recommended to be careful and never put hands or fingers inside the machine.

How to use a continuous feed garbage disposer?

  1. Run cold water.
  2. Turn on the disposer.
  3. Insert biodegradable food waste into the disposer (don’t overtax the machine).
  4. The disposer grinds the food waste and the motor stops when ready.
  5. Turn the machine back on and run cold water to flush the grinded food particles down the drain.
  6. Turn off the machine.

Batch feed

  • Load up the unit and close the sink flange before you grind up the food waste. The motor can only be activated when the cover is placed into the sink opening. (don’t overtax the machine).
  • Only runs when the drain opening is closed, this is called ‘covered operation’. So you can’t feed more food waste while the disposal unit is grinding. But this makes operation safer, especially for children.
  • Because of the batch feed processing the disposal unit requires a stronger engine in comparison with a continuous feed food waste disposer.
  • A batch feed garbage disposal is more expensive to buy.
  • Grinding food waste takes more time, because it is meant for grinding smaller amounts of food waste.

How to use a batch feed garbage disposer?

  1. Feed food scraps into the disposal.
  2. Run cold water.
  3. Place the cover into the sink opening.
  4. The garbage disposal turns on.
  5. Keep running water as it can flow a long the cover inside the sink opening.
  6. Turn off the disposer when the food waste is disposed. The motor stops immediately.

What can go in and what not?

What can go in?

  • Biodegradable food scraps only.

What not to put in?

  • Grease, oil and fat because it can congeal inside the drain pipes and clog up the sewer system.
  • Fibrous and stringy food waste, such as celery and corn husk. This is only applicable for less powered garbage disposals.
  • Meat bones, most disposal units can’t grind it up properly.
  • Everything that isn’t food waste, such as packaging material.

In Sweden some larger cities encourage kitchen waste disposals because they want to mine the food waste for biogas.

Features to look for

What are the most important features of garbage disposals and what are things to take in consideration? Below you can find a list with important features which helps you buying the best garbage disposal that suits your needs.

Metal versus plastic mount

When you want to purchase a durable food disposal then it is recommended to opt for a metal mounting system instead of a plastic mount. The mount connects the garbage disposal to your kitchen sink. Generally the higher powered food waste disposers are quite heavy so a metal mount will offer more durability.

food-disposal-metal-mount-plastic-mount
Metal versus plastic mounting system.

Waste disposal for dishwashers

Yes it is possible to connect a dishwasher to you garbage disposal when the disposal unit has a connection for the hose of your dishwasher. But first of, why would you want to connect your dishwasher to your food waste processor?

A dishwasher cleans your dirty plates, cutlery, pots and pans. And in this cleaning process a lot of food waste is disposed down the drain. To prevent clogging of your drain pipes it is a better idea to grind the food waste with a food waste disposal. By connecting the disposal to your dishwasher the discarded waste water goes through the garbage disposal and gets grind up before it is flushed away. Secondly it is more convenient and space efficient to connect your dishwasher hose to the garbage disposal instead of using all kind of drain connector parts to bypass the disposal unit.

Read more about connecting a dishwasher to a garbage disposal.

Waste disposal for septic system or septic tank

Can you have a garbage disposal when you make use of a septic system instead of the regular sewer system? A septic tank is watertight tank to store domestic sanitary wastewater underground in areas that are not connected to a sewerage system. a When your waste water is stored in a septic tank it isn’t recommended to use a regular garbage disposal unit. Why is that?

septic-tank-how-it-works
Source: EPA.gov

A septic tank breaks down matter by bacteria. But these bacteria can’t break down solids properly, and food waste is a solid waste. When you grind up your food scraps in the garbage disposal you flush the particles into your septic system. These food scraps will form a sludge inside the septic tank which grows in volume because the bacteria can’t break down the solid food waste quickly enough. This means that the rate of accumulation of the sludge is much quicker than the rate of decomposition. Besides, some types of food waste can’t even be digested at all, such as coffee grounds, fruit pits, meat bones and fats.

A septic tank isn’t meant for breaking down solid food waste.

The food sludge in the septic tank takes up valuable space inside the septic tank which normally is meant for waste water. In other words, it reduces the tank’s capacity and efficiency. But it also reduces the bacteria inside the tank which are needed to break down the particles from the waste water.

Septic garbage disposals

garbage-disposal-for-septic-tank-insinkerator
InSinkErator Evolution Septic Assist

When you want to use a garbage disposal in combination with a septic system it is recommended to purchase a specially designed food waste disposal. The difference with a regular disposer is that a septic garbage disposal breaks down food waste with released enzymes. These enzymes helps breaking down solid food waste inside the septic tank more quickly, because the enzymes attach to the food particles.

Will this mean that you can use your garbage disposal just like any other disposal unit which is connected to  a shared sewer system? Unfortunately not. You always need to be extra careful when disposing food scraps in the garbage disposal when you make us of a septic tank. Only dispose food waste which really can be disposed well. This means you need to stay away from discarding things like coffee grounds, fruit pits, meat bones, oil and grease to prevent extra maintenance and repairs for your septic system. And also never dispose objects that aren’t biodegradable at all, like food packaging. But this is of course applicable to every garbage disposal.

How to install a food waste disposal?

The installation process vary between different brands and types of garbage disposals. But generally it comes down to the following steps:

Tools needed:

  • Safety gear – Safety first.
  • Plumbers putty – For sealing of the sink flange in the sink opening.
  • Flat head screwdriver – For locking the mounting ring which locks the disposal unit in place.
  • Connectors and drain pipes – For connecting the garbage disposal neatly.
  • Tooth saw – For shorten drain pipe outlet.
  • Paint scraper – To remove old plumbers putty.
  • Towels – For cleaning possible water leakage.
  • Bucket – For catching water when a possible leakage occurs.
  • Hammer (optional) – For removing the plug inside the connector for the dishwasher.
  • Wooden dowel or steel punch (optional) – For removing the plug inside the connector for the dishwasher.

General installation process:

Please note that the steps below are an indication of the installation process. The process assumes that you want to replace your old garbage disposal (which is connected to your dishwasher) with a new one. Follow the steps in the instruction manual of your garbage disposal for proper installation.

  1. Make sure your current garbage disposal is empty.
  2. Make sure there is no water inside your sink.
  3. Turn off the power at the electrical panel.
  4. Disconnect and unplug your current garbage disposal as stated in the instruction manual.
    1. Insert a screwdriver into the mount and release the unit. Be careful, the disposal unit is heavy and can fall down. So place something below the unit to prevent damage.
    2. Remove all the mounting assembly.
    3. Remove the sink flange and old plumbers putty with a paint scraper.
  5. Disconnect the dishwasher hose.
  6. Install new mounting assembly as indicated in the instruction manual. Use plumbers putty to install the sink flange thoroughly to the sink.
  7. Remove the plug inside the dishwasher outlet from the garbage disposal. Use a hammer and a dowel or punch to remove the plug properly.
  8. Connect the garbage disposal to the mounting assembly. Use a screwdriver to lock the unit into the mount tightly.
  9. Make sure all the connections are secure. Run water to check for possible leaks.
  10. Plug in the power cord and turn the power back one. Test the garbage disposal.

How to maintain and clean a sink disposal?

After using a garbage disposal for a while it might become dirty and even a bit smelly. Bad odors are caused by bacteria from food waste residues which forms inside the sink opening and in the garbage disposal. How do your clean a kitchen garbage disposal and how often do you need to clean it?

According to Waste King, a manufacturer of garbage disposals, it isn’t necessary to clean your disposer. The disposer is a self cleaning device which cleans the internal parts with each use.

But what if you really want to clean the disposal and the sink opening? What are some tips you can follow? Below are some official tips and recommendations from InSinkErator, also a manufacturer of disposers.

  • Lemons – Neutralize bad odors by grinding citrus fruit. Put some slices inside the disposal, run some cold water and start grinding. The lemon helps to clean the inside of the disposer and releases a fresh smell.
  • Baffle – The baffle is the part that sits inside the sink opening, it is also called a splash guard. This rubber part can become really dirty and smelly as well. So it is recommended to clean this part regularly with some hot water and dish soap.

Manufacturers of food waste disposers

What are the best brands for garbage disposals? Below you can find a list with the official websites from well-known and popular brands:

Alternatives for kitchen waste disposals

What to do with you food scraps in the kitchen. Besides the use of a kitchen waste disposer there are alternatives for disposing this waste stream. Such as:

  1. Recycling bin dedicated for biodegradable food waste
  2. Composting bin for composting food waste

Food waste and the environment

Food waste that is disposed in your garbage can ends up on landfill. Inside this mountain of waste there isn’t a lot of oxygen available which causes the food waste to release methane when the waste decomposes. This gas is harmful for the environment when it is released in the open air, that is why it is being captured at landfills. This so called ‘landfill gas‘, or LFG, is captured and converted to use as a renewable energy source.

Collecting-and-Treating-Landfill-Gas
Collecting and Treating Landfill Gas | Source: EPA.gov

When you use a garbage disposal the food waste ends up in the sewer system. At the waste water treatment plant it is possible to capture the methane gas and convert it to a biogas to use it as a green source of energy, for instance for electricity or heat. Besides methane gas there are also concentrated remains of the food waste, these are called biosolids. This matter can be used as fertilizer products.

Did you know? A typical household throws away over 470 pounds of food waste every year.

See how food waste is recycled


Step Up: Recycle, Reuse & Reduce

The three arrows of the recycling symbol represent the three main stages of the recycling process: recycling, reusing and reducing. Together the arrows form a closed loop. Step up and implement eco-friendly replacements in your daily life.

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Join the movement! Step Up the waste hierarchy together to a goal of Zero Waste.

By Recycling.com/ 13 May 2019 Shares