Central Heating

Some congenital defects of one-pipe gravity steam heating are:

1. Large pipelines and valves for radiators should be allowed to return of condensate resistance against the flow of steam.
2. Steam and condensate flow in opposite directions, with the possibility of water hammer.
3. Air valves are required. The failure of these valves is always open air outlet can lead to a decrease in heat generation and fuel consumption.
4. Comfortable room temperature difficult to maintain if the radiator valves are governed by opening and closing. Automatic control of the steam from the boiler can lead to fluctuations in temperature in the room.

Additional disadvantages:

1. In the middle of the radiators can become air conditioning, related if they are not in the water-sealed. This occurs during the warm-up period, when a couple fills radiator nearest boiler and flows and is included in the return pipeline.
2. Installation of a valve at each end of all radiators are needed for the steam may be disabled. If this is not done, steam may be present in the return and supply lines.
3. The returns from each of the heat sink must be separately connected in wet header return or water-sealed in one form or another.

Benefits of steam in steam heating system include:

1. The air cannot enter the system as it is closed. Thus, a moderate vacuum created by the condensation of producing steam at lower temperatures.
2. Even, quiet circulation of steam is provided without air binding or noisy water hammer.
3. Temperature in the room can be closely and automatically adjustable thermostatic controls.
4. Air radiator valves is not necessary.

1. A relatively large size pipes are needed.
2. Only low pressure steam possible.
3. Condensate must return to the boiler under the influence of gravity.

Return-trap system resembles a steam heating system, except that the return of the trap provides a positive return condensate to the boiler. This type can be used, but in all large buildings, if the equivalent of direct radiation (EDR) with a capacity of not more than the return of a trap potential.

Advantages return-trap steam heating, include the following:

1. The dimensions of the pipes may be less due to the higher vapor pressure.
2. Return condensate to the boiler is rapid and positive.
3. The system reacts readily with thermostatic control.
4. Distribution of steam can be balanced by the use of throttle valves.

1. Steam circulation almost entirely depends on the pressure in the boiler.
2. Enough head room above the boiler must be submitted to the pipelines.
3. Physical constraints on the size and volume of return there are traps, which limit the capacity of the boiler.

Vacuum-return-line systems, similar to condensate-return-type installations, except that vacuum pump is set to low vacuum in the return line to return the condensate to the boiler. Advantages of vacuum-return line steam heating system include:

1. There is a positive return condensate to the boiler.
2. Air is removed from the steam mechanically, and the rapid circulation of steam.
3. Smaller pipe sizes may be used due to the large difference in pressure between the supply and return lines.

Advantages of this system are:

1. Steam circulation becomes more rapid.
2. Radiators heat efficiently at lower pressures.
3. Ventilation openings are not required.

1. The pair may be noisy at times like this and condensate flow in the same pipe.
2. Pipelines and radiator valves should be too large to accommodate both the flow of steam and condensate.

1. After the return water can be raised in the return of the network, condensate return lines can be upgraded.
2. High pressure or boiler-feed condensate pumps return condensate to the boiler.
3. Less radiators or heat-exchange units and smaller pipe sizes may be used.
4. If the system is used for both heating and steam processing, simplified system of pipelines can be used with mains, currently used for heating and technological equipment. Total condensate system can be installed.