Last Updated on April 16, 2024 by Real Men Sow
There are two main types of composting systems, open and closed. Open composting is often used to reduce waste and create fertilizer for gardens and crops. Closed composting systems are used to create heat that kills pathogens and breaks down food scraps into compost.
What are Closed Composting Systems (Closed-Bin)?
Closed composting systems can be set up in a variety of ways, but they all use some type of enclosed container that traps heat inside the bin. This produces temperatures high enough to kill harmful pathogens like E. coli, salmonella , and other foodborne illnesses. When the temperatures reach about 160 degrees Fahrenheit (71 degrees Celsius), it usually takes about two weeks for most food scraps to decompose completely.
In addition to killing potential pathogens, the heat generated by closed-bin composting systems speeds up the decomposition process by 10 times or more compared with open bins or piles. This makes it possible for you to get usable compost in less time than what’s required for open bins or piles.
Closed composting systems are the most common type of composting system. They are often referred to as “bin” systems.
There are two types of closed bins: tumbling and static. Both types use the same basic principles, but have different designs.
Different Types of Closed Composting Systems (Closed-bin)
Closed composting systems are a great alternative to open heaps or piles of decomposing organic matter. When you opt for this system, you will have the added benefit of improving air quality in your home or yard by reducing odors and airborne bacteria. There are two types of closed composting systems, they are:
Tumbling Bins
Tumbling bin composters are large plastic or metal containers that you fill with material and rotate periodically. These bins rotate as much as three times per week, depending on how much material is added at each turn. Tumbling bins typically have motors that make them turn automatically when it’s time for a turn (see below).
Static Bins
Static bin composters are similar to tumbling bins, except they don’t turn automatically; instead, you manually turn them using a crank or handle every couple of weeks or so.
Advantages of Closed Composting Systems (Closed-Bin)
One type of composting system that is better than open bins or piles is a closed composting system or closed-bin system. There are a number of reasons why these units hold bin cleaning and maintenance to a bare minimum, and they can also be used in conjunction with other composting methods.
Everything is Kept in Closed Bins with Tight Fitting Lids
This system prevents critters from getting in, odors are prevented, and organic matter is not visible to the public. A benign, barrel-shaped device that is usually mounted on a stand.
Has a Crank To Turn Your Bin
Closed systems mounted on a stand usually have a crank or a way to turn the bin so that it doesn’t get mixed up. It is much easier than manually turning a bin or using a spade to turn an open pile. Look for systems with a large crank handle, well-designed gears, and a sturdy frame. This makes it easy to turn even the largest loads.
Disadvantages of Closed Composting Systems
Not Enough Air Flow
There is very little chance for any object to accidentally get in or out of the lid. These systems do not allow for enough airflow to the bins. Even when you turn the pile, there isn’t much new airflow entering the bin.
Ingredients Stay Overly Damp
The ingredients will remain on the damp side. Even if you mix it as much as possible, the lid will keep the moisture from evaporating and allow air to circulate. Too much moisture can cause soggy material that doesn’t dry out enough to make compost in closed systems.
How To Handle the Downsides of Closed Composting Systems
Don’t worry, your ingredients won’t stink (once it dries out), and critters won’t be throwing a party in there. Simply remove the lid during the day or for a few days at a time. You can also add more brown (carbon) material to the bin, and turn it several times before temporarily removing the lid. By doing so, you’ll eliminate the biggest problem with these systems by allowing more air circulation and evaporation.
Passive and Forced-Air Composting
The most hated human intervention in home composting is the physical turning of the pile or agitation to increase oxygen. This is why closed-bin systems, which make it easier to turn the vessel, are so popular in composting. You can also adopt a passive/cold composting method where you do not do anything. However, you will need to wait a while before your compost is finished.
1st Method: Compromise
To create pockets in the compost pile, layer different-sized twigs, and branches. These sticks will eventually break down, but they won’t be as easy to digest as the other ingredients. Many of these sticks will be there when it comes time to harvest the compost. These are more of a nuisance to me than a benefit.
2nd Method: Adding PVC pipes
Place the large diameter PVC pipes horizontally or vertically in the pile, with large holes drilled into it. This is a great way to passively draw air through pipes and provide oxygen for the heap, particularly near the core. It’s up to you how many and whether you move vertically or horizontally. You can do anything to make it possible for air to reach the middle of your pile. This will help you get composted faster.
What is Hot and Cold Composting?
Hot Composting
This is the key to Quick Compost. It is not easy to raise temperatures high enough to quickly break down ingredients and kill disease pathogens or weed seeds above 140°F. To sustain this temperature, it takes a healthy supply (green) of nitrogen-rich ingredients. This is about 3x the amount of carbon to nitrogen.
To keep a compost pile hot in the home, you will need to provide some input. This includes manually turning the pile and adding moisture. You can check the compost temperature to see how it is cooking. If you have good organic matter, it is likely that the compost will be more complex.
Cold Composting
Those who make composts call this passive or lazily composting, is a hands-off method to make compost but it takes much longer. Cold composting is simply adding ingredients to a pile, and then waiting for it to dry (just like nature). For in-ground composting, the ingredients may be added to a pit or depression. It takes a lot of time to compost in this manner, depending on how many ingredients you have and the size of the material. It will take at most one year, and possibly two. This composting method is not recommended for use with diseased plants. The composting process won’t heat up enough to cause death.
A Comparison of Different Closed Composting Systems
With an open system, the temperatures are lower (around 130 degrees) and the compost comes out of the end of the process more like soil than a solid. With the closed system, it is hotter inside, reaching 160 degrees, so you get more of a composted product at the end of your cycle.
Closed systems are also easier to maintain because you don’t have to turn the pile over as often or keep it covered with leaves or straw.
Here’s a rundown of the most common types of closed systems:
Tumbler: This is a rotating bin that looks like a trash can with a lid on it. You use this type of composter if you have limited space in your yard or garden. It can hold up to two cubic feet and is easy to turn with just one hand! While this system is great for small spaces and families that don’t want to spend much time maintaining their bins, it does tend to be more expensive than other options because they need to be replaced every few years due to wear and tear from turning them so often (typically every two weeks).
Static Bins: A static bin composter is just like it sounds — a bucket made out of metal or plastic
