Monday, November 16, 2009

Ask the Engineer about what makes Rain Dispersal Units work.

In past posts I've been talking about the evolution of gutter covers. While most inventors were working to improve screens and solid top leaf guards there were a few who followed a different path. These few asked why improve on gutters when you can replace them with a product that forces rainwater away from the foundation and isn't a trough to collect debris.


Rain Dispersal units have been around for years. At first glance they look like they might be the answer to eliminating the chore of cleaning dirty smelly gutters. But they is a risk in that you have to remove your existing gutters completely in order to install the dispersers and if they don't work, then you're stuck with removing them and having to pay to have gutters reinstalled.
In other words, you'd be back to square one and out of pocket a considerable amount of water and money. At least if you choose the wrong gutter covers or leaf guards, you still have your gutters intact.

Well, let's take a look at rain dispersers and what makes them work. And then what could go wrong with them.

Basically the rain dispersal system is a series of angled vanes mounted horizontally to your fascia board. In theory as the rain water flows off the roof it hits the vanes with sufficient force (kinetic energy) to disperse the water droplets outward away from the foundation of the building.

They look promising until you ask yourself a couple of questions. What happens in slow rain fall when the rain water just drips off the roof-line? And what happens to the leaves and twigs that fall onto the dispersal fins?

Remember that what makes the device work is gravity and kinetic energy. Dripping water has insufficient kinetic energy to disperse in the vanes. It simply drips onto the vanes and drips from them straight down onto the ground leaving a drip line all around the foundation.

And what about the wet debris that lays on top of the unit? It blocks off the vanes so the rain water as it hits the dispersal unit is not dispersed but simply runs off onto the ground.

Again, maintenance involving the use of a ladder is required to clean off the top of the dispersal units. Certainly not a solution to ladder free maintenance.

No comments:

Post a Comment