Convection or condensing?
According to heating method, boilers are divided into convection (traditional) and condensing.
Convection boilers burning fuel has heat water, and exhausted gases threw up into the chimney. Their temperature is over 100 degrees, and this kind of energy is lost.
In condensing boilers, not only the heat from the combustion’s used but also the energy from chimney. Return cold water fetch energy generated when exhausted gases are cooled. Such system is more economical. In addition, condensing boilers use a closed combustion chamber and a coaxial chimney, which also saves fuel. Compared to traditional boilers, the consumption is 20-30 percent less. The gases in the chimney do not heat up more than 80 degrees, so can be used cheaper plastic pipes.
As a result, condensing boilers are more profitable.
System or Combi boilers ?
Combi
(double-pressure boiler) boilers need to produce hot water on demand for domestic use as well as heating. And as they directly provide central heating and domestic hot water, they have two separate output ratings.
Combi boilers are the most popular boiler type installed in homes across the Baltic states. They’re cost-effective and compact heating system which makes them ideally suited to homes with 1 or 2 bathrooms.
This system take water directly from the mains and provide central heating and hot water on demand. There is no need for any additional tanks or cylinders which will save you valuable space around the property but by not having a cylinder, they’re limited in terms of how much hot water they can provide. So, if you have 2 or more bathrooms, it’s worth considering a system boiler.
Tip: sometimes a combi boiler coupled with a storage electric water heater will be the best option. Such a system will allow you to have hot water when the boiler is turned off in summer time.
System boilers
System boilers are similar to combi boilers as they also take water directly from the mains. Unlike a combi boiler, a system boiler needs a hot water cylinder for storage. While this will take up some additional space, it does mean they are good for homes with a higher demand for hot water.
This is because, they’ll be able to supply hot water to 2 or more outlets at a single time without the water pressuring dropping.
Combi boiler sizing
It doesn’t matter what heat emitters you are using to heat your home, whether it be a radiator system or an underfloor heating system or even a combination of both.
The principle of heat loss sizing for your property doesn’t change.
Basically, the fabric of your home loses heat, depending on how well insulated the building materials used, such as the brickwork, the floor and the roof. This is known as the “U “value of the materials in question.
This” U “value is official expressed as the rate in Watts [W]) at which heat transfers through 1 square metre [m²] of the surface of a buildings material when there is a temperature difference of 1ºC between the internal and external environments.
So, if you have a property built from the late 1990’s onwards then you are safe to use this ready reckoner chart. This ready reckoner table is based on a brick and block cavity wall with mineral wool insulation having a total wall thickness of 312 mm has a “U” value of 0.3 W/mtr. The building regulation from the late 1990’s specify that this “U” value must be achieved, to pass the building regulations.
You need to ensure that you have the total floor area of your home, including the ground level, 1st floor, 2nd floor etc. It is the home’s / properties total floor area you need to calculate.
Power Output of Boiler Heating area with Height of 2.7 Mtrs & U Value of 0.3
- 4.5 kW ~ 55 Mtrs/2
- 7.5 kW ~ 85 Mtrs/2
- 9.0 kW ~ 110 Mtrs/2
- 13.5 kW ~ 165 Mtrs/2
- 15 kW ~ 180 Mtrs/2
- 22.5 kW ~ 278 Mtrs/2
- 24 kW ~ 300 Mtrs/2
For example – If your large home has a total floor area of 600 M/2, then you’re going to need a 48 kW Combi boiler (2 x 300 m2 = 2 x 24 kW – thus a 48kW output combi boiler)
If your total floor area is 440 M/2, then you’re going to need a 48 kW Combi boiler (1 x 300 m2 = 24 kW and 1 x 165 M2 = 13.5 Kw –always go up on the chart – you can turn a combi boilers output down , if you have it there , but you can never turn it up , if it doesn’t have the capacity – thus 24kw + 13.5 Kw = 37.5 kW total boiler output
What else to look at?
Type of ignition
Electronic or piezo (manual). Electric is more convenient and economical – the pilot burner does not burn all the time. Equipment Recall that combi boilers already have a pump, a three-way valve, expansion tank. To system ones, all this features should be purchased.
Control
can be electronic and mechanical. The electronic room thermostat itself regulates the set temperature (gas supply) in the heating system, which saves fuel. This is most effective if the sensor is installed outside and regulates the temperature in the room depending on the weather “overboard”. Part of control system is responsible for safety: flame and draft sensors, pressure control, thermostats, constant power supply, filters, stabilizers. A “smart” boiler can heat up the water in output rings by itself, and periodically start the circulation. Mechanical control will cost less, but it also has some possibilities.
Service
service department and a spare parts warehouse in the region is a big advantage
Electric boilers
This type of boiler has many advantages:
! The main thing – pairing with gas boiler it can additionally heat up your system in extreme frosts and be a spare in case of main boiler breakdown.
- noiselessness;
- no need for a separate room;
- no chimney is needed;
- ease of use;
- safety;
- low installation cost;
- boiler low cost.
Electric boiler consists of a heat exchanger with heating elements inside, as well as a regulation and control unit equipped with filters, safety valves, expansion tanks and circulation pumps.
Electric boilers are manufactured in two versions:
- single-phase;
- three-phase.
Single-phase boilers operate ~230V ,
Three-phase boilers ~ 380V.
Boilers with a power of more than 12 kW are manufactured only for ~380V.
Thermex Comby Gas Boilers main technical data
Thermex condensing boilers Advantages
Profitability
A gas boiler runs on natural gas or cylinder gas , which is more economical than solid fuel or electric boilers. Thermex quality’s designed for long-term intensive operation, therefore all components are of high quality and reliability. With compact size Thermex gas boilers can be placed in any room.
Safety
Thermex gas boilers are equipped with closed combustion chambers, which makes it possible to install the boiler in any place – the necessary combustion air and smoke exhaust pass through the chimney, so the boiler does not affect the ventilation of the room. Thermex are equipped with high-precision temperature, pressure and draft sensors. In case of any deviation from the norm, the gas supply stopped.
High performance
Due to the increased volume of the expansion tank, Thermex boilers can serve high-capacity heating systems.
High modulation rate
Automatic modulation speed regulates the burner power to ensure continuous and trouble-free operation of the gas boiler. As system runs smoothly risk of interruptions is reduced, as well as increased comfort levels and the ability to neutralize harmful substances that can be released into the air during combustion.
Comparts – ok
Service – ok
Installation issues – ok
Goods and spare parts – on spot
Conclusion – ok!