What to consider when performing calculations.
Calculation of the heat transfer of steel pipes is performed to determine the amount of heat released from the surface of the pipes. This calculation is necessary in only two cases:
- determination of the parameters of the heating system to obtain the required temperature;
- Calculation of heat losses for the subsequent choice of insulation materials
Heat transfer of pipes is calculated using the formula:
Q = K * F * Δt,
where
Q - heat transfer, Kcal / h;
К - coefficient of thermal conductivity, Kcal /( sq.m * h * 0С)
F - pipe area, sq.m;
Δt is the temperature head which is calculated as follows:
Δt = 0,5 x( tp + tо) - tв,
where: tп - water inlet temperature, 0С
tо - outlet water temperature, 0С
tв- temperature in the environment, 0С
The required values for determining the temperature head are taken according to the SNiP tables:
- tp = 80 0С
- tо = 70 0С
- tв = 20 0С
The coefficient of thermal conductivity depends on such data:
- pipe material;
- its diameter;
- number of parts for construction;
Calculate the area of the pipes is also easy:
F = P * d * l,
where: P = 3,14
d - pipe diameter
l - pipe length 
Let's give an example.
How much heat can a steel pipe with a length of 1 m and a diameter of 30 mm emit?
Since this is a theoretical calculation, let's take the value Δt = 55 0С.
Further:
F = 3.14 * 0.03 * 1 = 0.09 square meters.m
The coefficient of thermal conductivity of a steel pipe is approximately K = 11.5.
Q = 11,5 * 0,09 * 55 = 56,9 Kcal / h
As practically everything is much more complicated, for more accurate calculations it is necessary to consult a specialist.
It is necessary to take into account the secondary parameters influencing the heat transfer:
external shape of the pipe;
- its area and diameter;
- presence or absence of paintwork;
- physical properties of used heaters;
- air temperature in the house( or on the street);
- velocity of the coolant.
Increased heat dissipation.
To effectively increase the radiated heat, there are many ways:
- convector installation;
- painting of pipes with black paint;
- register setting;
- additional battery sections.
The convector is a curved pipe with metal plates. You can make it yourself or buy a more modern analogue in the store.
The use of a matte black paint to color the surface of the coolant also gives a good result. Aesthetically, this does not look very attractive, but if it's about comfort, then you have to choose.
Another inexpensive and quite popular design is the register. These are several interconnected wide pipes with welded sections. They also include towel warmers, radiators, main lines and even an ordinary steel pipe fixed around the perimeter of the room. 
Reduced heat dissipation.
In order to save energy, it becomes urgent to reduce the heat transfer of pipes in those sections of communications that are not used for their intended purpose, for example, when moving from one building to another or in an unheated room.
There are many options for using heat insulation materials for this. Manufacturers offer a wide range of choices, ranging from low-cost fiberglass to more expensive styrofoam types. You can buy pipes with the insulating elements already built into it.
Summing up, we conclude that using such calculations helps to save significantly and avoid many technical obstacles in the design of water and heat supply systems.
