The weather is beautiful! It’s fall, the leaves are gorgeous, it’s in the 70’s during the day and drops down to the mid 60’s at night. everything is perfect for your party this weekend. Uh-oh, the first cold snap of the year is coming! It’s going down to the mid 40’s! That means your party on the deck is going to be in 45-50 degree weather!

If that sounds familiar, it should, especially here in Atlanta where the only thing consistent about our weather is its inconsistency, and lately, no rain. This situation doesn’t necessarily mean your event is ruined. Hopefully, we can help.

Your event is either outside in the open or outside in a tent (if it’s inside the house, you’re not worried and you probably aren’t reading this). If it’s outside in a tent, then you have either an open tent or an enclosed tent. The different possibilities make for different solutions. That’s because there are 2 types of heat: Radiant and forced air and the 2 have different applications. Radiant Heat is like a fireplace. It heats objects, not space. The closer you get to the source of heat, the warmer you are. Forced air heat is like your furnace: you set the thermostat and the heater comes on and off and heats the room. You can walk most anywhere in the room and it feels pretty warm.

Radiant heat is best for open spaces like your deck or if you have an open tent. You’ve seen radiant heaters, no doubt. They’re usually about 6 or 7 feet tall and have a dome on them. A lot of people call them patio heaters. They cast heat out 5-6 feet from the heater. So you get a “circle” of heat about 10-12 feet in diameter. The closer you are to the center, the warmer you are.Patio heaters work at any temperature but the colder it gets, the less effective they are. Once it starts to drop much below 40-45 degrees, guests are less likely to stay outside. If it’s a casual party and guests know they will be outside and are likely to be wearing sweaters or jackets, you can use them in the colder temps. But if the ladies are dressed up in holiday attire, they usually don’t want to cover up their dress and are likely to spend most of their time indoors if they can. As the temperature gets colder, patio heaters become more likely the place for smokers to go where they can huddle around the heater while they smoke and then run back inside where it’s warm. Patio heaters also have the heating element up high so there’s little chance of something catching fire. A safety feature, no doubt, but it makes it more difficult to feel the heat if you’re seated at a table nearby. The patio heaters will also take up floor space which can be troubling if you’re trying to squeeze tables and chairs into a limited space. Because they usually have propane tanks in the base of them, fire code prohibits the use of the heaters in enclosed spaces. And, the last safety tip is to think of overhead clearance. That dome on top gets hot and it needs at least 3 feet clearance between it and any flammable surface, like a tent top or upstairs deck.

But you’re in a tent, so you’re trying to decide between the patio heater or a forced air heater. Remember, the tent needs to open sided to use the patio heaters. I usually advise my clients to spend the money to enclose the tent and then possibly add heaters. If the temperature is just going to be chilly, many times, just putting sidewall around the tent will do the job. Remember, every person in a tent is a 98.6 degree radiant heaters. If they talk a lot, then they’re forced air heaters. Cut down on the breeze and 30 or 40 people in a 600 sq ft tent can definitely warm things up. The cost for the sides will likely be a little less than the cost of a few patio heaters set up under the tent. Sides only without heat can work if it’s a warm day and the evening temperature is dropping to mid or upper 40’s. After that, you should add a forced air heater. The forced air heater will turn your tent into a extension of your house. You’ll have a thermostat just like your furnace that you adjust to keep it warm. The heaters are placed strategically so they can heat evenly (sometimes it takes more than 1) and they will always be near the side of the tent. That’s because they will have a large propane tank with a flexible hose connecting the two. The propane tanks stand outside the tent. Once you make the decision to add the heaters, the only question is how many and what size. The fine people that manufacture the heaters have produced a chart that tells you how many BTU’s you need to heat how many sq ft by how many degrees. So, in the table below, if I have 1200 sq ft, I need 90,000 BTU’s to get a 30 degree temperature rise. If the outside temperature is going to be 35, I want my space to be at least 65, so I need a 30 degree temperature rise. Our heaters are either 80,000 or 170, 000 BTU’s. In this case, I might add 2 heaters. That gives me 160,000 BTU’s, significantly more than needed, but my space will be much more evenly heated with 2 rather than 1 heater.

Temperature Rise

Sq Ft        10         20        30         40         50        60       70       80

400        8640   18560  30000  42560  56800 72000 88480  106240

800   17,280   37120   60000  85120  113600 144000 176960 212480

1000  21600 46400  75000 106400 142000 180000 221400 265600

We have more complete tables but space is limited here. You can multiply or add depending on the size of your space.

Of course, you can always call us and we’re happy to help.