Choosing a HydraTherm

There are three steps. You calculate the pond volume in US Gallons, then you calculate the heat loss per hour, and then you choose a boiler capable of generating the BTU's and couple it with an exchanger capable of transferring it. See info on BOILERS. See info on Exchangers.

Step 1: determine your pond capacity

Rectangular Ponds:

Capacity (US Gallons) = (Length in inches x width in inches x depth in inches) divided by 231

We'll work an example: Pond is 9 feet x 15 feet x 6 feet deep. We must convert to inches.

So we have 108 in x 180 in x 72 in equalling 1,399,680 cubic inches then we divide that by 231 giving a dividend of 6059 gallons US.

(all measurements in inches)

Circular Ponds:

Capacity (US Gallons) =5.9 X Diameter squared X Average Depth

We'll work an example on a completely different pond: Smaller pond is 9 feet in diameter and averages 3 feet deep. The math looks like:
5.9 x [(9)2 = 81] x 3 feet. The product of this is 1433.7 gallons.

(all measurements in feet)

Estimate heat loss in winter:

Option A. Heat loss calculation for uncovered pond:

Heat loss (Btu/hr) = 12 X pond surface area X desired pond temp.- coldest ambient temp.

We'll work an example: Pond is 9 feet wide and fifteen feet long, uncovered surface. I want the pond around seventy oF and it gets down to 28 oF at night. Sometimes colder, sometimes warmer.

Here's the math: 12 x (9ft x 15ft) x [70 oF minus 28 oF at night].

Works out to: 12 x 135 sq.ft. x 42 oF margins. = 68,040 BTU/hr

Option B. Heat loss calculation for almost completely covered pond:

Make sure an airspace is maintained between the surface of the pond and the cover. Do not float the cover directly on the pond.

Heat loss (Btu/hr) = pond surface area X desired pond temp. - coldest ambient temp

...... Customer Support