USA
Catalog   /   Climate, Heating, Water Heating   /   Heating & Boilers   /   Boilers

Comparison Viessmann Vitopend 100-W A1JB 34 kW 34 kW vs Viessmann Vitodens 100-W B1HC042 35kW 35 kW

Add to comparison
Viessmann Vitopend 100-W A1JB 34 kW 34 kW
Viessmann Vitodens 100-W B1HC042 35kW 35 kW
Viessmann Vitopend 100-W A1JB 34 kW 34 kWViessmann Vitodens 100-W B1HC042 35kW 35 kW
Outdated Product
from $1,438.77
Outdated Product
User reviews
0
1
0
3
TOP sellers
Energy sourcegasgas
Installationwallwall
Typedual-circuit (heating and DHW)single-circuit (heating only)
Heating area272 m²280 m²
Condensing
Technical specs
Heat output34 kW35 kW
Power supply230 V230 V
Power consumption150 W148 W
Coolant min. T40 °С40 °С
Coolant max. T80 °С80 °С
Heating circuit max. pressure3 bar3 bar
DHW circuit max. pressure10 bar
Consumer specs
DHW min. T35 °С
DHW max. T57 °С
"Summer" mode
Heated floor mode
Circulation pump
Control busOpenThermOpenTherm
Programmable thermostat
Boiler specs
Efficiency90 %108 %
Combustion chamberclosed (turbocharged)closed (turbocharged)
Flue diameter60/100 mm60/100 mm
Inlet gas pressure13 mbar
Max. gas consumption3.94 m³/h3.5 m³/h
Expansion vessel capacity6 L
Expansion vessel pressure1 bar
Heat exchangerstainless steel
Connections
Mains water intake1/2"
DHW flow1/2"
Gas supply3/4"
Central heating flow3/4"
Central heating return3/4"
Safety
Safety systems
gas pressure drop
water overheating
flame loss
draft control
 
 
gas pressure drop
water overheating
flame loss
draft control
water circulation failure
frost protection
More specs
Dimensions (HxWxD)725x450x360 mm700x400x350 mm
Weight40 kg37 kg
Added to E-Catalogaugust 2017june 2016

Type

Depending on the set of functions, boilers are divided into single-circuit and dual-circuit.

- Single-circuit boilers are equipped with one heat exchanger, in which the heat from fuel combustion is transferred to the heat medium of the heating system. The only function of such boilers is space heating. It is technically possible to use single-circuit boilers to provide hot water, but this requires an additional tank (the so-called indirect water heater).

- In dual-circuit boilers, the primary heat exchanger is supplemented by a secondary one. Due to this, such a boiler, in addition to heating the room, also provides a hot water supply. In this case, both running water and water accumulated in a special tank(see Built-in water heater tank) can be used.

Heating area

A very conditional parameter that slightly characterizes the purpose based on the size of the room. And depending on the height of the ceilings, layout, building design and equipment, actual values may differ significantly. However, this item represents the maximum recommended area of the room that the boiler can effectively heat. However, it is worth considering that different buildings have different thermal insulation properties and modern buildings are much “warmer” than 30-year-old and especially 50-year-old houses. Accordingly, this item is more of a reference nature and does not allow us to fully assess the actual heated area. There is a formula by which you can derive the maximum heating area, knowing the useful power of the boiler and the climatic conditions in which it will be used; For more information on this, see "Useful Power". In our case, the heating area is calculated using the formula “boiler power multiplied by 8”, which is approximately equivalent to use in houses that are several decades old.

Condensing

Boilers generate additional heat by condensing water vapour from combustion products. In such units, the combustion gases, before entering the flue, are passed through an additional heat exchanger, in which they are cooled, and the water vapour condenses and transfers thermal energy to the coolant. It allows you to increase the efficiency by 10 – 15% compared to boilers of the classical design — up to the fact that in many similar models, the efficiency exceeds 100% (for more details, see "Efficiency").

The condensation principle of operation is most often found in gas models (see "Power source"); however, solid and liquid fuel boilers with this feature are also produced.

Heat output

It is the maximum useful power of the boiler.

The ability of the device to heat a room of a particular area directly depends on this parameter; by power, you can approximately determine the heating area, if this parameter is not indicated in the specs. The most general rule says that for a dwelling with a ceiling height of 2.5 – 3 m, at least 100 W of heat power is needed to heat 1 m2 of area. There are also more detailed calculation methods that take into account specific factors: the climatic zone, heat gain from the outside, design features of the heating system, etc.; they are described in detail in special sources. Also note that in dual-circuit boilers (see "Type"), part of the heat generated is used to heat water for the hot water supply; this must be taken into account when evaluating the output power.

It is believed that boilers with a power of more than 30 kW must be installed in separate rooms (boiler rooms).

Power consumption

The maximum electrical power consumed by the boiler during operation. For non-electric models (see Energy source), this power is usually low, as it is required mainly for control circuits and it can be ignored. Regarding electric boilers, it is worth noting that the power consumption in them is most often somewhat higher than the useful one since part of the energy is inevitably dissipated and not used for heating. Accordingly, the ratio of useful and consumed power can be used to evaluate the efficiency of such a boiler.

DHW circuit max. pressure

The maximum pressure in the hot water circuit (DHW) at which it can operate for a long time without failures and damage. See "Heating circuit maximum pressure".

DHW min. T

The minimum temperature of domestic hot water (DHW) supplied by a dual-circuit boiler. For comparison, we note that water begins to be perceived as warm, starting from 40 °C, and in centralized hot water supply systems, the temperature of hot water is usually about 60 °C (and should not exceed 75 °C). At the same time, in some boilers, the minimum heating temperature can be only 10 °C or even 5 °C. A similar mode of operation is used to protect pipes from freezing during the cold season: the circulation of water with a positive temperature prevents the formation of ice inside and damage to the circuits.

It is also worth keeping in mind that when heated to a given temperature, the temperature difference ("ΔT") may be different — depending on the initial temperature of the cold water. And the performance of the boiler in the DHW mode directly depends on ΔT; see below for performance details.

DHW max. T

The maximum temperature of domestic hot water supplied by a dual-circuit boiler. For comparison, we note that water begins to be perceived as warm, starting from 40 °C, and in centralized hot water supply systems, the temperature of hot water is usually about 60 °C (and should not exceed 75 °C). Accordingly, even in the most modest models, this figure is about 45 °C, in the vast majority of modern boilers, it is not lower than 50 °C, and in some models, it can even exceed 90 °C.

Also when heated to a given temperature, the temperature difference ("ΔT") may be different — depending on the initial temperature of the cold water. And the performance of the boiler in the DHW mode directly depends on ΔT; see below for performance details.

Heated floor mode

The boiler has a special mode for underfloor heating systems.

Underfloor heating differs from conventional heating systems primarily by a lower coolant temperature — otherwise the floor could be too hot for comfortable use (plus, high temperatures are also undesirable for flooring and furniture installed on it). In addition, boilers with this function are distinguished by increased pump power. In order to ensure efficient circulation of the coolant through branched heating circuits that have rather high resistance.
Viessmann Vitopend 100-W A1JB 34 kW often compared
Viessmann Vitodens 100-W B1HC042 35kW often compared