Einsteinguy
Member
Due to the limitations of the usual Do It Yourself CO2 generating method, in which yeast growing in a bottle of sugar water produces CO2 according to its age, temperature, and mood. This simply doesn't allow enough control over the gas output. If the yeast is old, cold, or lazy, you get lackluster performance. The goal here was to build an enhanced version of the traditional DIY CO2 system that while still cheap and fairly simple, provides MUCH greater control over CO2 output, and that even allows for control by Co2 measuring equipment should one eventually choose to do so. Having a reservoir of CO2 in the balloon means that much less vigilance over the fermentation process is required. There are also no expensive and hard to find high-pressure cylinders, regulators, needle valves, or solenoid valves. And there are no trips to the welding supply shop for refills.
The Basic Setup
The system consists of the standard two/three liter soda pop bottle fermenter, connected to an air pump distribution manifold with air tubing. This manifold feeds both a Mylar balloon (the reservoir), and a small aquarium air pump. Put a small bottle for a bubble counter and filter between fermenter and air manifold. Also you can use more than one fermenter this lets you swap and get more Co2 per day.
The Bubble counter
This is a good way to monitor Co2 production and filter for overflow of fermenter.
The Balloon Reservoir
Since Mylar balloons leak Helium so slowly, I'm assuming that CO2 molecules, being larger, will pass through even more slowly, and that air will be slow to pass into the balloon gas reservoir from the outside. How much this diffusion of air and CO2 through the Mylar and attached tubing would affect the reservoir CO2 concentration over a long period of time is unknown, but it hasn't been a problem so far. Needless to say, a rubber balloon won't do; it's simply too porous.
Very Important
Mylar balloons seem to have some sort of valve mechanism (Mylar flaps that push shut under pressure) inside the balloon so that gas can flow in but not out. Be sure to place the tubing into the balloon far enough so it gets past this valve -- about 6 inches or so. If the tubing is in far enough, air blown into the balloon will be come back out when the balloon is squeezed. Seal the tubing in place with aquarium sealant, Shoe Goo, Tape or whatever.
Pressure Release
If the pressure in the fermenter/balloon/lines gets too high some sort of pressure release mechanism is needed. If the pressure from the fermenter should get too high (i.e. the balloon is completely full) the excess CO2 just leaks out around the press-fit lines or pops red safety plug on manifold.
The Air Pump and Its Enclosure
The air pump is placed in a sealed container to keep air from leaking into the pump housing and mixing with the CO2. Putting the pump in a sealed container has an added advantage: it significantly reduces pump noise, especially if it is set on a balled-up piece of cloth to provide some mechanical isolation.
Air tight connections on your bottle caps.
This is simple. Use a drill bit that is smaller than tubing. (If it fits tight inside tubing it is just about right). After drilling hole cut tubing at a sharp angle on end 45 degrees or more. Use pliers to pull tubing through hole.
Off at Night
In my setup, the AC power for the air pump comes from the timer that controls the lights, so CO2 delivery stops at lights out.
Yeast Recipe
2 cups sugar, 1 tsp yeast, 1 tsp baking powder, 1 vitamin B pill
Directions
Place small amount hot water in bottom of bottle then pour in sugar. Shake well to dissolve sugar. Fill bottle with cool water two to three inches from top. Take temp of sugar water it should be 80 degrees or below. Add baking power and vitamin pill (some people do not use these two ingredients) Shake well. Pour yeast in and Do not shake it will lay on top and slowly sink into water. Do not shake fermenter after this it is not necessary and can cause it to overflow. Fermenter will also pull water out of bubble counter if squeezed.
The only maintenance required is recharging the fermenter bottle when the bubbles slow down. In bubble counter an advantage of this system is that since the quantity of CO2 going into the room isn't dependent on the state of the fermenter, you don't have to pay very close attention to how things are going in the bottle. You'll want to have a look at the pump every now and then to see how the diaphragm is holding up.
Einstein
The Basic Setup
The system consists of the standard two/three liter soda pop bottle fermenter, connected to an air pump distribution manifold with air tubing. This manifold feeds both a Mylar balloon (the reservoir), and a small aquarium air pump. Put a small bottle for a bubble counter and filter between fermenter and air manifold. Also you can use more than one fermenter this lets you swap and get more Co2 per day.
The Bubble counter
This is a good way to monitor Co2 production and filter for overflow of fermenter.
The Balloon Reservoir
Since Mylar balloons leak Helium so slowly, I'm assuming that CO2 molecules, being larger, will pass through even more slowly, and that air will be slow to pass into the balloon gas reservoir from the outside. How much this diffusion of air and CO2 through the Mylar and attached tubing would affect the reservoir CO2 concentration over a long period of time is unknown, but it hasn't been a problem so far. Needless to say, a rubber balloon won't do; it's simply too porous.
Very Important
Mylar balloons seem to have some sort of valve mechanism (Mylar flaps that push shut under pressure) inside the balloon so that gas can flow in but not out. Be sure to place the tubing into the balloon far enough so it gets past this valve -- about 6 inches or so. If the tubing is in far enough, air blown into the balloon will be come back out when the balloon is squeezed. Seal the tubing in place with aquarium sealant, Shoe Goo, Tape or whatever.
Pressure Release
If the pressure in the fermenter/balloon/lines gets too high some sort of pressure release mechanism is needed. If the pressure from the fermenter should get too high (i.e. the balloon is completely full) the excess CO2 just leaks out around the press-fit lines or pops red safety plug on manifold.
The Air Pump and Its Enclosure
The air pump is placed in a sealed container to keep air from leaking into the pump housing and mixing with the CO2. Putting the pump in a sealed container has an added advantage: it significantly reduces pump noise, especially if it is set on a balled-up piece of cloth to provide some mechanical isolation.
Air tight connections on your bottle caps.
This is simple. Use a drill bit that is smaller than tubing. (If it fits tight inside tubing it is just about right). After drilling hole cut tubing at a sharp angle on end 45 degrees or more. Use pliers to pull tubing through hole.
Off at Night
In my setup, the AC power for the air pump comes from the timer that controls the lights, so CO2 delivery stops at lights out.
Yeast Recipe
2 cups sugar, 1 tsp yeast, 1 tsp baking powder, 1 vitamin B pill
Directions
Place small amount hot water in bottom of bottle then pour in sugar. Shake well to dissolve sugar. Fill bottle with cool water two to three inches from top. Take temp of sugar water it should be 80 degrees or below. Add baking power and vitamin pill (some people do not use these two ingredients) Shake well. Pour yeast in and Do not shake it will lay on top and slowly sink into water. Do not shake fermenter after this it is not necessary and can cause it to overflow. Fermenter will also pull water out of bubble counter if squeezed.
The only maintenance required is recharging the fermenter bottle when the bubbles slow down. In bubble counter an advantage of this system is that since the quantity of CO2 going into the room isn't dependent on the state of the fermenter, you don't have to pay very close attention to how things are going in the bottle. You'll want to have a look at the pump every now and then to see how the diaphragm is holding up.
Einstein
