60/40 is a used to save helium costs. A balloon is inflated with 60% helium and 40% air using a nozzle like the 60/40 Helium/Air™ Inflator made by Conwin. At the same the balloon inflates with helium, air through the air intake holes on the nozzle enters the balloon. By covering the air intake holes, it is possible to fill the balloon with 100% helium.
The reason to use 60/40 is to save money on helium. However, since air does not float, float times for balloons using this technique are impacted. For some events especially when using larger balloons like 30-36" latex balloons helium is often wasted filling the entire balloon with helium especially when the event is only one day. Even with 40% air, Conwin claims a 36-inch balloon would float for 3-5 days. The impact of using 40% air can greatly reduce the cost of inflation, but will have no impact on the event if for example the event is only 1-2 days. Another option is to use a 60/40 mix along with hi-float. Hi-float coats the inside of the balloon sealing the helium in for a longer time. Combining 60/40 with hi-float can save money. 60/40 is not recommended on 9-inch balloons even if hi-float is used. 60/40 could be used on foil balloons, but we do not know of any balloon nozzle equipment manufacturer making a 60/40 nozzle to fill foil balloons. We have no chart or guidelines for a 60/40 mix on foil balloons.
Noting that altitude and other environmental conditions will affect float times Conwin claims the following when using their 60/40 Helium/Air™ Inflator.
- 11" Latex Balloon without Hi-Float will float 8-12 hours.
- 11" Latex Balloon with Hi-Float-3-10 Days.
- 16" Latex Balloon 30+hours.
- 24" Latex Balloon 2-4 Days.
- 30" to 36" Balloons 3-5 Days.
* Do not assume these times to be 100% accurate. To be safe expect float times to be less than what they say. If you choose to use this technique, we recommend testing it before using it for an important event.
Example of 60/40 Nozzle