Dialing In - Kegerator Tube Lengths

Once you start using kegs at home, it becomes abundantly clear that you need to follow some guidelines to ensure that foaming does not become a problem. Especially if you are modifying your kegerator to accommodate more than one keg, it is important to pay close attention to your beer line length, CO2 gas line length, temperature, and the ideal push for each type of beer that you will be dispensing.

Beer Line Resistance Reference Chart

3/16" I.D. plastic beer line *most common size 2.7 PSI per foot
1/4" I.D. plastic beer line 0.7 PSI per foot
5/16" I.D. plastic beer line 0.17 PSI per foot
3/8" I.D. plastic beer line 0.11 PSI per foot
1/2" I.D. plastic beer line 0.025 PSI per foot

Typical kegerators with draft towers usually have about 1.5 feet distance from the top of the keg to the faucet tap, so with a flow rate of 10 seconds per pint using a 3/16" inner diameter beer line you would need around 8 feet of beer line if you were dispensing a keg served with 10 PSI of pressure. This would give you a CO2 saturation volume of around 2.3 at 40 F.

Use the Beer Line Length Calculator to calculate the line lengths for your kegerator based on the beer style you plan to dispense.

Becoming familiar with how the carbonation process works is a good start. Realize that the ideal temperature and pressure will be dictated by the type of beer being dispensed. Also, the length of your beer line will have an affect on the resultant qualities of the pour.

First of all, it is a good idea to be familiar with the way carbonation affects the taste of beer, in all its varieties. Generally, the less complex the taste, the more bubbles you want to put into the beer to balance our the final taste.

A rich malty and hoppy beer needs as little as 7 PSI of pressure behind it, while for a light lager style beer, you will usually want something like 10-12 PSI to push it properly. You will need a Two Keg Primary CO2 Regulator capable of pushing gas at different pressures, if you wish to serve various beers of different types using one CO2 cylinder through your home draft system.

Temperature also greatly affects the amount of CO2 gas that is absorbed into the liquid beer. The lower the temperature, the more easily the beer accepts CO2, and the higher the temperature, the more difficult it is to introduce CO2 into the beer. This is why it is imperative that you determine or discover what the ideal temperature and CO2 pressure is for the beer that you are serving. [CO2 Pressure Chart]

The length of the beer line can also affect the amount of push needed for optimal pouring. Most home draft systems will have beer line of 3/16" ID (inner diameter), but it is good to check and make the adjustments necessary. Look at the type of beer line and CO2 gas line that comprise your home draft system. If possible, note the restriction value of the line. Some beer and gas lines may have the same inner diameter, but because of the materials they are made from, will expand or contract at different rates. This quality of your line is called the restriction value.

There will be some restriction from gravity and from draft hardware such as any shank and the spigot, but it is pretty negligible. Gravity has an effect, and it is only .5 pounds per foot of rise or fall of additional restriction. There are some other considerations as well, such as making sure that your beer line is cold and the possible use of beer gas (CO2 and Nitrogen mix).

If you have more than one type of beer that is being served from the same gas source, you will want to either split your CO2 line or add a secondary regulator to step down the pressure to the keg of beer that will be served at the lesser pressure. The most expedient solution is to daisy chain secondary regulators to your primary CO2 regulator. This will allow you to adjust the pressure according to the rule of thumb above, so that if you have two beers that are being served from the same cooling chamber, you can adjust the pressure on the different kegs to match the ideal pressure for the non-ideal temperature.

Related Kegerator Articles :
Dialing-In your Home Draft System: Modifying a Draft Tower -- Learn how a few quick modifications tips from Kegerators.com on your draft tower can allow for additional faucets.
Dialing in Your Home Draft System's Temperature -- Kegerator foaming? Loosing beer each time you pour? You may not have your temperatures set properly for the amount of CO2 in the beer being dispensed.
CO2 Carbonation Chart -- Handy-Dandy Slow Force Carbonation Chart featuring Pressure vs. Temperature in Degrees Fahrenheit.