Koi Pond Heating Equipment

Heating your Pond - is it necessary? - What's the best method?

Well frankly - NO - you don't have to heat a koi pond. Koi are poikilothermic, which means their body temperature is governed by the surrounding water temperature. They are hardy 'cold water' fish which will withstand and proliferate in a wide range of water temperatures. Koi have been known to survive temperatures of 1 Deg C (33 Deg F) up to 32 Deg C (90 Deg F) without ill effect. It is not the extremes of temperatures which seem to bother Koi, but rather the duration of any temperature extremes and rapid temperature fluctuations which can cause problems for the Koi keeper.

In the UK, the problems are generally not associated with extremely cold water temperatures during winter, but rather the length of our rather dreary, 'cold' and miserable winters and low water temperatures which cause problems. A Koi's immune system functions properly at temperatures over around 12.5 Deg C ( 55 Deg F). Under this and the immune system ceases to function effectively and at lower temperatures, a Koi's ability to fight diseases can be severely reduced. Unfortunately, many pathogenic bacteria and a range of parasites can survive and even proliferate at temperatures down to around 5 Deg C, meaning that your Koi are at their most vulnerable at temperatures of between 6 Deg C and 12.5 Deg C.

As water temperatures in the UK can be in this range for up to 5 months of the year, you will appreciate why it is that most of the disease problems with which we as Koi keepers are faced (generally in Springtime) may be precipitated by this length of relatively cold water temperatures.

In addition, smaller ponds of say, 2000 gallons or less will be more prone to the affects of unstable water chemistry as the pond volume is comparatively small and even in ponds with a larger volume but of a shallow nature can exhibit the same problems. Any water parameters which change too quickly will stress the Koi. One of these water parameters is obviously water temperature, and ideally, this should not fluctuate by more than 0.5 deg C per day.

Over winter, and indeed in Spring, we may get very cold and frosty nights, but followed by sunny days, which can result in temperature fluctuations of up to 2 deg C or even more in small, unheated, shallow and uncovered ponds. The degree of temperature change obviously varies across the UK but one of the most important benefits of heating a Koi pond is the ability to achieve a stable water temperature at all times.

The objective of any heating installation is therefore not to heat the pond to high temperatures for reasons of, for example, high growth, or just to keep our koi active. It should be targeted at controlling the water temperature to avoid the temperature 'trap' or the fluctuations described above.

In our own installations, we heat our stock (and private) ponds until Christmas time, by leaving the pond thermostats set to 16 Deg C ( 61 Deg F). This extends the Koi's Summer and keeps them feeding and growing well. From around the turn of the new year we then progressively turn down the temperature by 0.5 Deg per day until the water temperature returns to ambient levels (whereby the water temperature falls to match the surrounding average air temperature). We then give all our Koi a shortened winter for about 1/2 of January and all of February and then switch the heating on again at the beginning of March. During these cold months we allow the water temperatures to drop as low as we can , normally down to 4 or 5 Deg C. This does absolutely no harm to healthy Koi for this short period but helps to 'cleanse' the pond environment and reduce the numbers of any remaining parasites or bacteria.

 This means that we are effectively giving the Koi a 10 month Summer and a maximum two month Winter. We are also only using our heating systems for around 4 - 5 months of the year, and not heating at all for the two coldest months, January or February, and since we are not trying to raise our pond temperatures to ridiculously high levels, we are also reducing extra fuel bills as much as possible.

 It is an established and accepted fact that Koi live longer if given a 'natural' winter, and we do NOT subscribe to the view that Koi ponds must be heated all the year round to ensure their well being. Indeed we would go further, in that ponds that are heated all the year round must be maintained much more carefully to avoid problems as the Koi never get a period of 'rest' or inactivity and a Summer maintenance regime is absolutely vital to ensure that no problems are encountered. Weekly water changes and filter maintenance must be adhered to whilst water temperatures are elevated simply because whilst you are providing a warm comfortable environment for your Koi, you are also providing the same conditions for parasites and bacteria which can and often do multiply very quickly in ponds kept 'warm' during winter, whilst the not so vigilant Koi keeper is snuggled up in front of a log fire with ample supplies of mince pies and Brandy, completely forgetting about daily or even weekly pond maintenance tasks!

 If you do decide to heat your pond you will have a number of options, including heating using gas, oil, electricity and now electricity in the form of air source heat pumps. Whilst Gas installations are more expensive to install, they are comparatively cheap to run.   Oil is now becoming very expensive, and the capital outlay for an oil installation is generally also more expensive than a gas installation. Direct electric heating systems are easy and relatively cheap to install, but are the most expensive to run - Now however with the introduction of air source heat pumps, you have the ability to increase the efficiency of your heating system installation by up to 400% as air source heat pumps can deliver up to 14 times the energy consumed and are now by far the cheapest method of heating your pond ( see below). However - the choice is yours!

To give you an idea of costs, Gas systems can cost as little as 70p per thousand gallons per day to run, whilst oil is currently around £1.00 per thousand gallons per day, and direct electric heating costs start from around £1.30p per thousand gallons per Day.

 DC inverter air source heat pumps can cost as little as 50p per thousand gallons per day.

Insulating a heated pond is vital for keeping costs under control and even a simple cover made from a heat retentive material such as bubble wrap or (ideally) polycarbonate will reduce costs substantially. As an example we have halved the costs of heating our 25,000 gallons of stock ponds by covering all the heated ponds with triple wall polycarbonate sheet. The costs of the insulation will pay for itself in the first season.

Air source Heat Pumps.

What is a heat pump?:- A device that converts electrical energy to kinetic to thermal energy through the use of compressed refrigerant. It works like a refrigerator in reverse. It draws heat from the air, and transfers that heat to the pond water. A heat pump does not create heat like a resistance heater, it extracts heat from one location and transfers it to where it is needed.

Heat pumps operate on the principle of a closed circuit similar to that used in the household refrigerator. One side is cold the other hot. For instance a refrigerator removes heat from its inside as well as from the food, and transfers it via the condenser to the outside air, which is warmed.

Heat Pumps utilise the sun’s free heat by collecting and absorbing energy from the outside air. This energy is then transferred to the koi pond water. Your existing koi pond pump circulates the water through the heater which warms the pond. The unit contains a fan that draws in outside air and directs it over the surface of the EVAPORATOR (energy collector). The liquid refrigerant within the EVAPORATOR coil absorbs the heat from the outside air and the refrigerant becomes a gas. The warm gas passes through the compressor where it is compressed to form a very hot gas, which then passes through the CONDENSOR (water heat exchanger). It is here that the heat exchange occurs as the hot gas gives up the heat to the cooler koi pond water circulating through the coil. The pond water becomes warmer and the hot gas is cooling down as it flows through the CONDENSOR coil, returns to its liquid form and, after passing through the expansion valve, the whole process begins again.

Depending upon the design of the installation and ambient temperatures, it is possible to get in excess of 14 times more heat per kw of power consumed using the latest heat inverter heat pump technology. So for every 1kw of power consumed, up to 14kw of heat can be produced to heat the water.

Inverter heat pumps are the latest type of heat pump to be made available and are even more efficient - up to 20% more efficient than a standard A/C heat pump. This is because DC (direct current) technology is around 96% efficient compared to A/C technology (alternating mains current) which is only around 46% efficient. In addition, with DC technology the compressor within the heat pump can change speed as the heating demand varies, so that when an inverter unit is first switched on, it will run at full power. As the water temperature approaches the set point, it will slow down and run at a lower power rating and within the set temperature range the heat pump will be running at a low power level, therefore consuming less electricity. With an A/C model, the unit is either on or off, and when on and running the unit will run at full power. So inverters are able to vary the load to suit the heating requirement and therefore will cost even less to run than even their A/C counterparts.

Inverter models are more expensive to buy, so have not been commonly used in Koi pond heating, however now inverters are more competitively priced, and indeed some are cheaper to buy than many of the older technology A/C models. All of our heat pumps are now offered with a three year parts and labour warranty which is backed up by nationwide distribution and so now has never been a better time to invest in these super efficient units.

All types of Heat pumps are at least 3 times more efficient than other heating methods including gas, oil, and direct electric. Savings in terms of running costs can be as much as 70% less than for direct electric heating, and up to 40% less than oil or gas.

If you do decide to heat your pond, air source heat pumps are undoubtedly by far the most cost effective method of doing so, being economical to purchase and install when compared to gas or oil installations as well as being cheaper to run, and are way way cheaper to run than direct electric systems.

Remora On/Off A/C Heat Pumps.

The latest heat pump range are from Remora - an ultra modern heat pump which are super efficient, and are very competitively priced. The range is offered with a three year parts and labour warranty and seven year warranty on heat exchanger and compressor (parts only after third year) Wi-Fi connectivity built-in* allowing remote control of the operation and settings, high efficiency performance with advanced stepless DC inverter systems on inverter models that automatically control the running speed of the compressor and the fan. Super quiet in operation - 30db at 10m range. Heating and cooling modes, works efficiently down to - 15 deg c. Black ABS corrosion resistant cabinet. Features EEV throttling technology which adjusts the gas flow and increases COP by up to 20%, Spiral Titanium heat exchanger is 40% more efficient than standard titanium heat exchangers. Uses R32 gas for environmentally friendly operation. Winter cover included as standard

Remora Inverter Heat Pumps.

The latest inverter heat pumps are from Remora - an ultra modern heat pump range which are super efficient, and are very competitively priced. The range is offered with a three year parts and labour warranty and seven year warranty on heat exchanger and compressor (parts only after third year) Wi-Fi connectivity built-in* allowing remote control of the operation and settings, high efficiency performance with advanced stepless DC inverter system that automatically controls the running speed of the compressor and the fan. Super quite in operation 30db at 10m range. Heating and cooling modes, works efficiently down to - 15 deg c. Black ABS corrosion resistant cabinet. Features EEV throttling technology which adjusts the gas flow and increases COP by up to 20%, Spiral Titanium heat exchanger is 40% more efficient than standard titanium heat exchangers. Uses R32 gas for environmentally friendly operation. Winter cover included as standard

Remora Professional Inverter Heat Pumps.

Everything about the Remora Professional says quality, whether it’s the performance, the engineering or the controls – put it all together and you’ve got a heat pump that looks every bit as good as it performs. Our unique partnership with the manufacturer of our Remora heat pumps allows us to deliver the performance and features our customers want, the result is a range of heat pumps that deliver exceptional COP and heating efficiency, the Remora Professional Inverter range introduces our first 14kW plug and play model and a new 35kW model at the top of the range. Matching the Remora Professional’s performance, are the highest levels of British quality control and engineering, the powder coated steel case features a cut out fan grill adding to the already sleek and stylish design, the patented, flush fit touch control LCD screen is fully waterproof and requires no additional cover, the full colour display offers precise digital read outs and the heat pump is controllable via Wi-Fi using Smart Life App. The build quality of the Remora Professional is backed by a four year parts and labour warranty and a ten year warranty of the compressor and heat exchanger (parts only after year four). The Remora Professional features external control (subject to connection to a suitable Wi-Fi network), allowing remote access to the heat pump for changing parameters and diagnosing running issues, this removes the need for an engineer to attend site or for customers to self-diagnose issues, advanced parameters allow for all aspect of the heat pumps running to be tailored to your requirements. The full stepless DC Inverter system allows the Remora Professional to be responsive and efficient, choose Boost mode to deliver fast heating, Silent mode for night time running, Eco for the most efficient running or simply leave in Smart mode for intelligent day to day heating or cooling of your pool or pond, all selectable at the touch of a button. Our 8kW, 10kW and 14kW Remora Professional heat pumps come fitted with mains cable, RCD and plug as standard, making them suitable for outdoor sockets, the other models in the range will require electrical installation by a qualified electrician.