Posts Tagged ‘glycol’

Hydronic Snow Melt Systems: Say Goodbye to Shovels

Tuesday, June 8th, 2010
Source: Birdman

Source: Birdman

Will your hydronic snow melt system be ready when winter comes and the snow starts to fall? There is an alternative to constant shoveling and de-icing.

Some homeowners and businesses are keeping their concrete driveways and other exterior walkways maintenance-free by installing ice and snow melt systems.

Not only do these in-slab hydronic snowmelt systems eliminate plowing, backbreaking shoveling, and icy spills, they prevent potential damage to the concrete caused by snow-removal equipment and corrosive de-icers.

How Snow Melt Systems Work

The heat element is either hydronic tubing or electric wires. This heat element is embedded in concrete to transfer its heat energy to the slab.


Propylene Glycol Mixture: Geothermal Freeze Protection

Monday, March 29th, 2010

Our installers often ask why we recommend a 25% mixture of propylene glycol to water for geothermal loopfields.

Propylene glycol at a 25% mixture by mass yields a freezing point of about 12.5 degrees F. Since propylene glycol is slightly more dense, 1.036 g/cm3 to 1.0 g/cm3 for water, this equates to a mixture by volume of 25% freezing at 12.95 degrees F. 20% by mass freezes at 18 degrees F. This is sufficient for interior hydronic lines.

Our pump sizing is based on the viscosity of a 25% glycol mixture by volume. We use this mixture because it uses the minimum amount of glycol for pumping viscosity losses while providing freeze protection.

The reynolds number also plays a part in the ratio. The greater the volume of the thicker glycol, the faster you have to pump to reach turbulent flow. Use 25% glycol to 75% water with our product in a correctly designed geothermal loop field for optimum performance.

Since our product is inhibited, it has a glycol ratio of 96%.  Four percent is the additives for corrosion resistance and the anti-foaming agent. This is the highest ratio available in this type of glycol. Some products labeled -100 can be as low as 65%. If you mix that at 25% you would actually be only 16.25%.

Download the Freeze Safe 100 PDF Spec Sheet for more information.