If you participate in projects that require digging or pouring concrete during cold weather, you’ve probably used or considered using ground heaters. Ground heaters can extend working seasons into the winter and make tasks otherwise complicated by low temps a bit easier. They can be used to thaw frozen ground, cure concrete, and even to warm up surrounding air temperatures. How ground heaters work depends on which type of ground heater you’re using; the most common are hydronic heaters and heated blankets. Hydronic heaters work by heating a propylene glycol mixture and pumping it through long loops of hose that are placed over the area to be heated. Heated blankets work via heating elements that run through the blanket and distribute heat over the surface of the blanket.
Why Use Ground Heaters?
As mentioned earlier, there are a few good reasons to look into using a ground heater.
1. Thaw Frozen Ground
Even with power tools, digging through frozen ground is unnecessarily time consuming and labor intensive (and without power tools, it’s pretty much impossible). Not to mention, most specifications prevent teams from placing concrete on frozen ground. Without ground heaters, that could mean pushing pause on all concrete projects for months at a time! Using a heater will make digging a (relative) breeze and keep operations running all winter long.
2. Cure Concrete
Concrete curing involves a chemical reaction that requires fairly specific temperatures. When temperatures aren’t high enough (above 40-50°F), the necessary chemical reactions will slow down and the concrete can essentially stop curing.
According to the American Concrete Institute (ACI), when concrete is poured at or below 42°F, there must be heat protection for an adequate cure.
Ground heaters can keep concrete at ideal temperatures during the entire curing process and help achieve max cure strength.
How do Ground Heaters Work?
Hydronic heaters are portable and can be rented out for projects or bought (a better option if you’ll be using a heater frequently). They use a propylene glycol mixture to heat large areas of ground. Here’s how they work:
- A boiler heats the propylene glycol mixture (this mixture effectively conducts heat).
- The heated mixture is pumped through a length of hose that is laid in loops over the area to be heated.
- A vapor barrier is used to cover the hoses and to keep moisture from escaping.
- Typically, Insulated blankets are also laid over the vapor barrier.
Heated blankets offer all the portability and convenience of hydronic heaters and then some — they take less time to install and remove and, because they take up less space, are easier to transport.
Instead of long loops of hose and a propylene glycol mix, heated blankets use electric heating elements that run through the blanket and heat the ground surface.
- The blanket is spread out over the area to be heated and plugged in.
- Electricity powers the heating elements that run through the blanket.
- Heated blankets typically include an insulating top layer that traps heat and keeps the blanket working even more efficiently.
Powerblanket provides ground heating blankets including ground thawing blankets and concrete curing blankets. If you’re interested in these heating options, please give us a call at 888.316.6324. We’d be happy to answer any questions!