Which well pump to choose

Having your own water source is great. And it’s even better if they are wells – they usually have cleaner water than wells and can supply water for longer. But to get water from it into the house, you need a whole system, the basis of which is a pump for the well.

Selection parameters

Well pumps are easy to distinguish even by their appearance. They are a long cylinder made of stainless steel or plastic. Naturally, stainless steel models are more expensive – the steel must be of high quality (usually food grade AISI304). Pumps in a plastic case are much cheaper. Although they are made of a special impact-resistant plastic, they must be handled carefully – it still does not tolerate shock loads very well. All other parameters will have to be selected.

Water consumption and pump performance

To water in the house or dacha was with sufficient head, you need equipment that can deliver the required volume of liquid. This parameter is called pump capacity, measured in liters or milliliters (grams) per unit of time:

• ml/s – milliliters per second;
• l/min – liters per minute;
• l/h or cu/h (^m3/h) – liters or cubic meters per hour (one cubic meter equals 1000 liters).

Well pumps can lift from 20 liters/min to 200 liters/min. The more productive the unit, the higher the power consumption and the higher the price. Therefore, this parameter should be chosen with a reasonable margin.

The required amount of water is calculated by two methods. The first takes into account the number of people living and the total flow rate. If there are four people living in the house, the water consumption per day will be according to the norms of 800 liters (200 liters / person). If from the well will be not only water supply, but also irrigation, it is necessary to add some more moisture. The total amount is divided by 12 (not 24 hours, because at night the water supply is used at a minimum). We get how much we will spend on average per hour. Dividing it by 60, we get the required pump capacity.

For example, for a family of four people and watering a small vegetable garden goes 1500 liters per day. Divided by 12, we get 125 liters/hour. In a minute it will be 2.08 liters/minute. If you often have guests, you may need a little more water, so the flow rate can increase by about 20%. Then you will need to look for a pump with a capacity of about 2.2-2.3 liters per minute.

Lift height (head)

Selecting a pump for a well, you will inevitably study the technical characteristics. There are such parameters as lift height and immersion depth. The lift height – also called head – is a calculated value. It takes into account the depth from which the pump will pump water, the height to which it must be raised in the house, the length of the horizontal section and the resistance of the pipes. It is calculated using the formula:

Example of calculating the required head. Let it be necessary to lift water from a depth (the place of installation of the pump) of 35 meters. The horizontal section is 25 meters, which equates to 2.5 meters of lift. The house is two-story, the highest point is the shower on the second floor at a height of 4.5 meters. Now we do the math: 35 meters + 2.5 meters + 4.5 meters = 42 meters. This figure is multiplied by the correction factor: 42 * 1,1 5 = 48,3 m. That is, the minimum head or lift height is 50 meters.

If there is a hydroaccumulator in the water supply system of the house, not the distance to the highest point, but its resistance is taken into account. It depends on the pressure in the tank. One atmosphere is equal to 10 meters of head. That is, if the pressure in the GA is 2 atm, when calculating instead of the height of the house substitute 20 meters.

Immersion depth

Another important parameter in the technical characteristics is the depth of immersion. This is the value from which the pump can pump out water. It varies from 8-10 m for very low-power models to 200 m and more. That is, when choosing a pump for a well, you need to look at both characteristics at once.

How to determine how deep the pump should be lowered? This figure should be in the passport for the well. It depends on the total depth of the well, its size (diameter) and flow rate (the speed at which the water arrives). In general, the recommendations are as follows: the pump should be located below the water mirror at least 15-20 meters, but it is better even lower. When the pump is switched on, the liquid level drops by 3-8 meters. The remaining amount above it and is pumped out. If the pump is very productive, it pumps quickly, it should be lowered, otherwise it will often shut down due to lack of water.

Diameter of the well

An important role in the selection of equipment is played by the diameter of the well. Most domestic borehole pumps have dimensions from 70 mm to 102 mm. In general, this parameter is usually measured in inches. If so, then it is easiest to find three and four inch copies. The rest are supplied to order.

Type of well pump

Immediately a few words about the type of installation of the pump for the well. In general, there are submersible and surface devices. Surface are good in that they are always in plain sight and available, in the water source is only a hose. But there is one “but” – they have a maximum depth of suction – about 8-10 meters. Wells of this depth, if there are any, then very rarely. There are, of course, surface pumps with ejector. They can get water from a depth of 20-30 meters, but such installations have a low productivity, and the meter reels with twice the force. So there is essentially no choice – the pump for the well requires only a submersible pump.

Two types of submersible well pumps are most widely spread: vibrating and centrifugal. Vibratory is attractive for its price – they cost many times less than the cheapest centrifugal. But they are not recommended for pumping drinking water. The reasons are as follows:

• When working, the vibrating pump creates perceptible vibrations in the water, which lifts sediment from the bottom. Therefore, the water supplied by such a pump will never be clear.
• There is a strong opinion that the use of vibrating pumps significantly reduces the life of the well – it silted up faster.
• The pump beats strongly against the walls of the well and makes a lot of noise. The beating can be weakened by putting safety rubber rings on the casing (if the whole construction fits into the well), and nothing can be done about the noise.
• These pumps differ in small capacity and depth from which they can lift water.

That is, vibrating pumps for shallow wells, from which water is pumped for irrigation. Then their use is justified.

A centrifugal pump for a well is much more productive equipment. Water is pumped due to the rotation of impellers, which create a discharge in the center and increased pressure at the periphery. Due to the high pressure at the edges, the water rises up, and a new portion is sucked into the low-pressure zone in the center. This is how the water rises.

Centrifugal borehole pumps are quiet and can lift water from great depths. Their disadvantage is that they are sensitive to mechanical impurities that may be in the water – the working parts wear out. Therefore, they are suitable only for clean water – the maximum content of impurities – from 100 g/m3, some models with high speed limits are even more – up to 50 g/m3. Good models have several (up to 10) impellers, the inclusion / exclusion of which regulates the power flow.

What brands to give preference

When choosing a particular brand of pump for a well, pay attention to two things. The first is the number of positive and negative reviews. Only here it should be borne in mind that positive reviews are rarely written – if the equipment works about it and do not remember. Only if before that there were some problems that the new pump solved. That’s when there are chances that there will be a positive review. Getting a negative review when there are problems is much more likely. So the ratio of positive to negative reviews will be biased. You can simply compare the amount of positive and negative regarding different brands.

The second thing to pay attention to is the presence of service centers and warranty workshops in your region. So that if a problem arises, it can be quickly and easily solved, rather than traveling far away. This is also very important.

What should I pay attention to (apart from technical specifications)? The presence and number of degrees of protection. Good (and expensive) equipment can have the following built-in mechanisms:

• protection against dry running (shutdown in the absence of water);
• protection against overloads and electrical discharges (from overheating);
• sand cleaning system;
• from water leakage (check valve, it can be put without problems additionally).

From this list it is very desirable that the pump for the well had protection against dry running and overloads. These are basic things that extend the life of the unit. Cleaning from sand, of course, is good, but the equipment is quite expensive. And a check valve can be put immediately at the pump outlet on the suction hose (pipe).

Brands of pumps that are considered the best

The opinion of experts does not always coincide with the opinion of users, but it is also worth listening to them. They recommend mostly expensive brands, but not just so, but because they really work well. So, here is a list of firms that are trusted by the pros:

• Aquarius. At a relatively low price is quite decent quality.
• Jilex. Normal work – about 5-6 years – with the correct selection of parameters.
• Potok. Chinese-Russian, but they work normally.
• Aquario (Aquario). Normal quality for not very much money.
• Grundfos (Grundfos). The leader in quality, but also in prices.
• DAB. Decent competitors for Grundfos at lower prices.
• ESPA. Good quality. Problems can be with service – not all regions have service centers.
• Willo (Willo). Another of the market leaders. Good quality at more or less decent prices.
• ZDS. These pumps for wells have shown themselves well. On them, the manufacturer gives a 2-year unconditional warranty – replacement in case of breakdown for any reason.
• Acua. The entire hydraulic part is made of stainless steel, but the dimensions of these pumps are not suitable for most wells.
• Vodomet series Prof. Quite decent quality, but repair only in a service center.

This is a more or less complete list of brands that professionals recommend.