Koi Pond Heating with a Heat Pump

Heat pumps can be successfully used to heat koi ponds through the winter and summer months.

Using a heat pump as a pond heater will significiantly reduce your pond heating costs.

For use with koi ponds, it is important to select a heat pump that can operate down to low temperatures in order to maintain the required temperature of the pond throughout the winter.

Typically a koi pond will be kept at between 10c and 15c throughout the winter.

The range of heat pumps that we recommend for koi ponds are the excellent Duratech Dura+ range. The Dura+ range come in different sizes of 7kw, 10kw, 14kw and 19kw of output heat. Beware of heat pumps that will only work down to about +7c, as these will become inefficient in very cold weather.

The Dura+ range can operate down to -10c and have a "hot-gas" defrosting mechanism which will quickly clear away any ice that may form on the heat pump at low temperatures.

Efficiency

Heating a koi pond with a heat pump will always be significantly cheaper than using gas, oil or direct electric heating.

A heat pump will return between 2.8 and 6.7 times its input energy as heat depending on the air temperature.

This factor of efficiency is called the COP (Coefficient of Performance) and you can view a graph of how the unit performance varies with air temperature on the Dura+ product page Here

At an air temperature of 0c, the Dura+ has a COP of about 4.

The Dura+7 has an input power of 1.2kw and therefore with an air temperature of 0c, it will still output 4 x 1.2 = 4.8kw of heat for only 1.2kw of input power.

The COP rises to over 6 meaning that the heat pump can produce 6 x 1.2 = 7.2kw of heat from only 1.2kw of input power.

These heat pumps therefore have an efficiency of between 280% and 670%. A typical gas boiler will only be around 85% efficient and direct electric about 95% efficient.

This high efficiency makes heat pumps the cheapest form of heating, even at low air temperatures.

 

Running Costs

As an example of running costs, the Dura+ 7kw heat pump has an input power of 1.2kw (5.2 amps).

If your electricity costs say 9p per kwh then the running costs of the heat pump would be 9 x 1.2 = 10.8p per hour while the heat pump is operating

Except in extremely cold spells, and if sized correctly, the heat pump should not need to run 24hrs a day.

The heat pump will heat the pond to the required temperature and will then switch off.

The running time of the unit will depend on the air temperature and how well the pond is insulated or covered.

Assuming the heat pump needs to run for say 7hrs per day, the running cost for a Dura+ 7 unit would be 7 x 10.8p = 75.6p per day

Warranty

The use of the Duratech Dura+ range of heat pumps on koi ponds does not invalidate the warranty in any way.

The only provision in the warranty document states that for koi ponds, the PH must be kept between 7.0 and 8.5 which is fairly typical for most koi ponds.

The concentration of medicinal chemicals that may be used in koi ponds is not suffucient to cause any damage to the unit.

The Dura+ units have a titanium heat exchanger which is highly resistant to corrosion from all chemical types including chlorine in swimming pools.

A copy of the warranty document is listed at the bottom of the Dura+ product listing, or can be viewed Here

Example Installations

Below are some photographs of a heat pond being heated through the winter using a Dura+ heat pump.

The photos were taken in December 2009.

 

Another example below of a Dura+ heat pump heating a koi pond taken March2010

 

The pond owner reported that the heat pump has worked extremely well and maintained the pond temperature at 15c despite the snow !

The running costs were reduced by approx 60%

Another recent installation was on a 14,000 gallon pond in Norfolk and used a Dura+14kw unit to heat the pool.

The pool owner reported:-

"I am writing to say I have been very impressed with the heat pump, I reckon over the past 3 weeks it has already saved me over £200 in heating oil"

The initial purchase cost of a heat pump may be higher than a traditional electric or gas pond heater, but you will soon recover the outlay through greatly reduced running costs.

Using a heat pump to heat your pond is also a more environmentally friendly method than using fossil fuels such as gas or oil and so you can also reduce CO2 emmisions and do your bit for the environment !

Any Questions?

If you have any questions regarding the use of heat pumps to heat koi ponds, please Contact Us and we will be delighted to answer them for you.