This is the most important question you should ask your potential HVAC and generator rental partner, whether you’re an experienced event professional or if this is your first time renting equipment.
Q: How much air do I need to cover my enclosed, tented space?
A: There are several factors that go into calculating what the rental industry calls air tonnage, which is the required amount of air to cool or heat an event space given its circumstances. These circumstances include the following:
- Time of year. Is your event during the summer, winter or somewhere in between?
- The actual structure – is the tent all-white? Does it have any clear windows, clear walls or clear roof? Are the walls made of vinyl, solid hard wall or glass? How tall are the tent’s legs?
- How many people will be inside the tent at any given time?
The Mathematics of HVAC Rental
For every 100 square feet of general tent space, the standard requirement to cover that area with cold AC is one ton of air. For 1,000 SF, the standard is ten tons. For 10,000 SF, the standard is 100 tons and so on and so forth.
There are variables that can change these requirements.
Is the tent structure all-white? This is a commonly missed question when it comes to a potential rental partner and is extremely important. Many tented weddings and galas go for the wow factor with a clear tent, which can present an awesome visual. At the same time, fully enclosed clear walled and roofed tents also create a magnifying glass effect during the warmer hours of the day. If not handled correctly by the tent company and HVAC rental company, this situation gets unbearably hot and stuffy in a hurry. A vinyl tarp should be placed over the clear roof by the tent company until shortly before the event begins, and tonnage should be doubled in many cases to plan for the additional heat created in this scenario. This depends on the time of year and time of day the event is taking place, so air tonnage on a clear tent can vary widely given each event’s circumstances.
Keep in mind the height of the tent’s legs, too. There is a big difference in the space to cool when you have 13’ legs versus 8’ legs. Let your rental rep know the tent legs’ height to help him or her create your quote accurately.
The simplest reason more air may be needed is the time of year. If it’s the middle of July in Florida, more air tonnage will be required as outside temperatures can hover above 100 degrees, making the AC units work that much harder to keep things cooler inside your tent, just like a residential air conditioner must do during summer months for a house, apartment or condo.
The third factor is how many people are going inside the tent during your event. For every 100 people, an extra ton of cold air may be needed to keep the space comfortable. This may not be as heavy a factor in cooler months, but during the summer, your estimated attendance count must be considered.
A quick example of how air tonnage requirements can change quickly:
- 50’x100’ all-white tent with 10’ legs for 500 guests in November in Florida: 50 tons required
- 50’x100’ all-clear tent with 13’ legs for 500 guests in July in Florida: 105 tons required
When you’re looking for a quote or multiple quotes from temporary HVAC and power providers, give as much of this information to your rep as possible and if they don’t ask these questions or secondary questions when you bring the information up, ask them why. When cooling or heating your tent structure, air conditioning works best during an event when no one thinks about it. There are other aspects involved in creating a successfully cooled event, such as technician on-site and correctly sizing a generator for temporary HVAC (including backup power), on top of any audio/visual and catering power distribution needs that are regularly needed. Those topics will be covered in separate blog posts here in the future.