Garbage Disposals for Disposing Food Waste in the Kitchen

Guide for Garbage Disposals

Grind Biodegradable Food Scraps & Flush It Down The Drain

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Garbage Disposal Guide

What is a garbage disposal?

A garbage disposal is an electronic device, also known as a food or under-sink compactor, that grinds up biodegradable food waste and scraps under your sink. Then the food particles are flushed away with water down to drain.

The disposer is installed inside one of your kitchen cabinets and sits between the sink drain and the drain pipe.

In the disposal unit, you will find a rotating grinding plate with swiveling metal impellers that grind and shred the food waste into small particles. These food remains are then flushed into your sewage system through your plumbing.

It is also an option to connect your dishwasher hose to the discharge of the garbage disposal unit.

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How does it work?

An in-sink garbage disposal doesn’t work the same way as a paper shredder, blender or food processor. This means that it doesn’t shred or chop the food scraps with sharp cutting blades.

Rather, an under-sink garbage disposal grinds food scraps with a plate or grinder wheel.

The wheel is equipped with pointy impellers or lugs which spins around extremely fast, creating a centrifugal force. When biodegradable green waste is fed into the unit, the wheel grinds up the food forced against a stationary grinder ring. The remaining food particles are then washed down the drain with, preferably, cold water.

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

Will ground food waste clog the drain pipes?

A garbage disposal should not clog your drain pipes if it is used properly. But a jammed up disposal unit or clogged drain pipe can happen. Here are a few reasons why your drain pipes can clog. It can clog because:

• Fat, grease or oil was disposed of with warm or hot water, which congeals inside the drain pipes.
• Hard, stringy, or fibrous food waste was fed into the disposer which couldn’t be processed properly and jams up the disposer or drain pipes.
• Too little water was used to wash the food waste particles away which caused a jammed up drainpipe.

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The pros and cons of a food waste incinerator

Pros:

• Reduce the volume of food waste.
• Convenient and hygienic way of disposing of 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.
• Wastewater treatment is more difficult because of food waste particles.
• Not every garbage disposal might fit your sink, such as a farmhouse sink or Kraus sink.

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

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Features to look out for

What are the most important features of garbage disposals and which ones should be taken into consideration when looking for a disposal to buy? Below you can find a list of important features that will help you choose the best garbage disposal for your needs.

• Induction or Permanent magnet motor – While factually speaking permanent magnet motors are the better option, consumer reviews and experiences clearly show the induction motors, especially ones from InSinkErator, can also get the job done well with their multiple grinding stages which make up for the motor’s disadvantages.
• Batch feed or Continuous feed – Do you want a disposal unit that can run continuously? Or do you want a safer food waste disposer that only runs in batches? In short, a continuous feed disposer keeps running until you turn it off and you can add waste to the unit while it runs. Meanwhile, a batch feed disposal only grinds up food waste in small batches and the device is closed while on so you can’t add more food waste.
• Plastic or Metal mount – If noise is a concern or you want a durable garbage disposal mount then you should opt for a sturdy metal mount, which minimized vibrations and with that noise and everyday wear and tear. However, if you don’t mind a little noise or have a limited budget then a plastic mount will definitely serve you well too. If you find noise level an important characteristic of disposal and would like to read more about quiet disposals you can check out our blog post on in.
• Power of the motor – How much power do you need? It all depends on the number of food scraps you want to grind during the day or the number of users. We recommend choosing at least a 1/2 horsepower disposal. When you have lots of food waste or a large household you need more horsepower to process and dispose of all the food waste.
  • Light use (1-2 users) – 1/3 HP
  • Medium use (2-4 users) – 1/2 & 3/4 HP
  • Heavy use (4-6 users) – 1 HP (can handle almost all types of food scraps, check our recommended 1 HP garbage disposals)
• Grind stages – Waste disposers can have one, two or even three grinding stages. More stages mean smaller food particles, and thus a lesser chance of clogging. In general, more powerful garbage disposals have two or three grind stages, also known as multi-grind stages. The less powerful models only come with one or a single grind stage. When you want to grind up all kind of food scraps, including (small) bones, then it is recommended to look for a waste disposal which comes with a two or three-stage grind system.
• Size of the unit – Make sure the garbage disposal can fit under the sink base and in the kitchen cabinet. It is also important to check if there is enough room to install the unit, as well as the drain pipes and optional hose for your dishwasher.
• Built quality – A waste disposal with good built quality will last longer, is quieter and vibrates less during use. When you are choosing your unit make sure it is made of stainless steel metal and that the mount, which connects the disposer to your sink, is durable.
• Ease of installation – The installation of a food waste disposal is supposed to be quite easy, but the installation process may vary per brand. Most popular brands, like Waste King and InSinkErator, try to make it as convenient as possible to install the unit in your kitchen cabinet by offering a product with a user-friendly mount system. If you are not sure how to install the unit properly, you can also hire an expert to install the unit for you.
• Power cord – Not all garbage disposals come with an attached power cord. With some units, you will need to buy and attach a power cord yourself.
• Air switch – With an air switch you can activate the disposal by pressing a button that is installed in a convenient spot in your kitchen, for instance, it can be mounted in your countertop near your sink. The button sends an air pulse to the control box that switches on the garbage disposal. You don’t need electricity, the switch works with just air that is pushed through PVC tubing to the control box.
• Connecting to dishwasher – If you have a dishwasher that you want to connect to the disposal it is recommended to look for one with an inlet for the dishwasher. Most garbage disposals have an inlet for connecting the dishwasher hose. This inlet is closed with a plug that needs to be removed before connecting the dishwasher to the unit. You may need to purchase a dishwasher kit that connects these two machines to each other.
• Warranty – Check the warranty for each brand and model before purchasing a food waste disposer. Some manufacturers offer a lifetime limited warranty, while other brands only offer a warranty of a few years.
• Can your plumbing handle it – Before installing a food waste disposal make sure your plumbing and the shared sewage system can digest food particles. Please investigate with your local municipality whether it is permitted to use a garbage disposal.

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Types of garbage disposals

Before buying a garbage disposal there are three characteristics you should make a choice on, which will define the type of disposal you will opt for. These characteristics include:

1. Type of motor (induction motors / permanent magnet motor)
2. Type of feed (continuous feed / batched feed disposals)
3. Type of mount (metal mount / plastic mounts)

In case you are looking for special types of garbage disposals, for instance, disposals for farmhouse sinks, septic tanks or dishwashers. We also have a page about that which you can find here.

1. Induction motor or permanent magnet motor

What is an induction motor?

An induction motor is a high-speed electrical motor that is commonly used in InSinkErator and Kitchen Aid food waste disposals. The induction motor creates a constant flux through a physical connection to the rotor. Reaching the motors maximum RPM takes longer in comparison to a permanent magnet (PM) motor and maximum speed tends to be slower than that of PM motors.

Generally speaking, the induction motor tends to be heavier too, but unlike PM motors, induction motors can have multiple grinding stages to make up for it.

What is a permanent magnet motor?

A permanent magnet motor is an electric motor that uses permanent magnets, hence the name. These motors are more efficient than induction motors. Because of the magnets, the motor produces a consistent and instantaneous motor flux. This means the motor instantly runs at maximum speed, so all the power is directly available.

For a garbage disposal this is very convenient, especially when the chamber contains fibrous or large quantities of food waste. For bathed feed garbage disposals, a permanent magnet motor is preferable, because this type of waste disposals grinds up food waste in batches and thus needs the immediate power of the motor.

Another advantage of a permanent magnet motor is that the unit is smaller and thus lighter. Also, it tends to clog up less often than induction motors.

Currently, the two leading brands for garbage disposals are Waste King and InSinkErator. Waste King uses permanent magnet motors in their disposals and InSinkErator uses induction motors.

If you would like to know more but the differences between the two brands, and which one is better, you may want to read our more extensive blog post on the topic.

2. Continuous feed & batch feed

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

What is 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 of food scraps during the cleaning process.
• A continuous feed is less expensive to buy in comparison with a 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 into the food disposer while it is running. Therefore, it is recommended to be careful and never put hands or fingers inside the machine.

What is batch feed?

• Load up the unit and close the sink flange before you grind up the food waste. The motor can only be started when the cover is placed into the sink opening. (don’t overload the machine).
• It will only run if the drain opening is closed, this is called ‘covered operation’. This way you can’t feed more food waste while the disposal unit is grinding. But this makes operation safer, especially for children.
• Because of this, the batch feed disposal unit requires a stronger engine in comparison with a continuous feed food waste disposer, and therefore also tends to be more expensive.
• Grinding your food waste takes more time because it is meant for grinding smaller amounts of food waste.

3. Metal mount or plastic mount

When you want to purchase a durable food disposal it is recommended to opt for a metal mounting system rather than a plastic mount. This mount is what connects your garbage disposal to the kitchen sink. Generally, the higher-powered food waste disposers are quite heavy so a metal mount will offer more durability but also stability.

Plastic mounts are known to be less stable. This instability allows for more intense vibrations which makes your disposal noisier but also more prone to wear and tear in a shorter period of time.

What type of garbage disposal do most people buy?

Most people buy a continuous feed garbage disposal that produces 3/4 to 1 HP, check our recommendations for powerful food waste disposals here. These types of high-powered waste disposals can handle most food waste and can be used for medium to heavy use for an average household.

The garbage disposals from InSinkErator and Waste King are very popular, because of the quality and ease of installation. Also, people tend to buy disposals that can be connected to a dishwasher, since most people use a dishwasher in their kitchen. See our comparison between Waste King and InSinkerator disposers here.

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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 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.

Sometimes it can be a challenge to figure out whether or not the food scraps from your dinner are allowed to go in the garbage disposal. This is because it is difficult to define precisely what food leftovers can and cannot go into your at-home disposer, as this varies based on the manufacturer and the power of your garbage disposer model. However, some types of food waste that all disposers should handle and other kinds of debris should generally not go into your food waste disposal.

Soft fruits and vegetables are fine to dispose

First, let’s name some straightforward food waste that your garbage disposal should be able to process without a problem. All garbage disposals can handle water, obviously, but more precisely, using cold water is highly recommended.

A general rule of thumb for food wastes that can go into any food disposal is: if a baby can eat it, then your disposal can handle it too. If you have food scraps or leftovers, that should be okay to put in your disposer, but you can help your disposal by cutting the chunks into smaller pieces for whatever reason you are unsure about it.

Generally, soft fruits and vegetables without pits or seeds are fine, and so are cooked fruits and vegetables. Other foods that any garbage disposal should be able to process include cereal, smoothie drinks, citrus rinds, and soups.

Chance of clogging and damaging

Unfortunately, the list of foods that cannot go in your garbage disposal is longer and a bit more confusing than the list with food waste that can be discarded in a disposer. The more obvious non-food items, such as cigarette buds, paper, and glass, and continuing with oil, grease, and fats, are especially damaging if combined with hot water.

This combination further increases the chances of clogging. Next up are the hard food scraps like bones, seeds, and pits, which can damage your disposal’s interior motor. For example, beef or chicken bones, apple cores, and peach or avocado pits.

Furthermore, expandable foods like pasta, rice, bread, or oatmeal should also not be thrown in the garbage disposal, as they will expand from the water in the chamber and cause clogging. Lastly, coffee grounds, eggshells, and high fiber foods such as artichokes, celery, lettuce, asparagus, carrots, corn husks, and potato peels also have been known to decrease a disposal’s performance by wrapping themselves around the blades.

As a final note, these are general recommendations, and we advise consumers to consult the manufacturer directly for specific questions. Garbage disposals with more power can likely process some of the items listed in the “chance of clogging and damaging” paragraph, but this should be researched based on the specific model and make.

The recommendations described in this section should assure safe usage of all food waste disposal models, even the models with low power.

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What does it cost?

A garbage disposal grinds up your food waste directly under your sink. The food particles are then flushed away down the drain. But what is the average price of a garbage disposal? The cost of a disposal unit depends mostly on the type of disposal (continuous or batch feed), the power of the motor and the built quality.

• 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 results in 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. This is because commercial or industrial machines need to be very powerful in order to be able to continuously process high volumes of food scraps and other biodegradable waste.

Comparison of home & office disposal prices

Price comparison between popular brands

Below you can see a price comparison between three of the most popular brands for garbage disposals: InSinkErator, Waste King, and Moen. We have compared multiple disposers, calculated the average price, and compared this to the power of the engine in HP. Also, see our more in-depth comparison between Waste King and InSinkerator here.

What is your budget?

Click on the link below to find the right garbage disposal that suits your budget:

• Garbage disposal under $50
• Garbage disposal under $100
• Garbage disposal under $200

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How to install a garbage disposal?

The installation process varies per brand and garbage disposal type, but generally, it comes down to the following steps:

Tools needed:

• Safety gear – Safety first.
• Plumbers putty – For sealing the sink flange to the sink drain.
• Flathead screwdriver – For locking the mounting ring, which keeps the disposal unit in place.
• Connectors and drain pipes – For connecting the garbage disposal neatly.
• Tooth saw – For shorting 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 from the outlet for connecting the dishwasher.
• Wooden dowel or steel punch (optional) – For removing the plug from the outlet for connecting the dishwasher.

If you do want to install your garbage disposal by yourself, rather than hiring a plumber or handyman, you should at least think about purchasing an installation kit to facilitate the process by making sure you have all the parts you need.

General installation process:

Please note that the steps below are only 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 in 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 use it as a handle and turn it anticlockwise to release the unit from the mounting ring. Be careful, the disposal unit is heavy and can fall down. So place something below the unit to prevent damage in the unit and cabinet.
   2. Remove the whole 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 from the dishwasher outlet from the garbage disposal. Use a hammer and a dowel to remove the plug properly.
8. Connect the garbage disposal to the new mounting assembly. Use a screwdriver as a hand to lock the unit into the mount tightly.
9. Make sure all the connections are secure. Run water to check for possible leaks.
10. Plugin the power cord and turn the power on and test the garbage disposal.

Installation guides

General guides:

• How to replace a garbage disposal
• How to install a garbage disposal

Waste King:

• https://www.wasteking.com/support/videos

InSinkErator:

• https://insinkerator.emerson.com/en-us/support/videos
• https://insinkerator.emerson.com/en-us/support/literature

Moen:

• https://www.moen.com/customer-support/installation-help