Condensing boilers were first developed commercially in

the late 1970’s/early 1980’s. They depended for their

high efficiency on low temperature heating systems (such

as under-floor heating) or on mild weather and

controlled heating systems which then run at lower than

design temperatures. The disadvantage of these

“conventional” condensing boilers is that they do not

condense in mid-winter – except with specially-designed

low temperature heating systems.

However the R Series Boiler is a new generation of boiler

in which condensing occurs throughout the year

regardless of heating system temperature - and at even

higher efficiencies on maximum mid-winter load.

In addition, the R Series boiler is a dual-fuel condensing

boiler - burning either natural gas, Class D oil, LPG or

kerosene in a clean manner and within EEC NOx

emission standards.Busby Hall, North Yorkshire - OIL CONDENSING

Bannatynes Health Club, Kent - GAS CONDENSING

Sutton Police Station, London - DUAL FUEL CONDENSING

OUTPUTS:from 10kW

to 535kW

R SeriesNEW GENERATION CONDENSING BOILERS

TheCombustionProcess

When natural gas is burned to produce heat, itcombines with oxygen in the air supply toproduce carbon dioxide and water vapour.These, together with nitrogen from the air formthe flue gases.

Approximately 10m3 of air is needed for each1m3 of natural gas so that the volume of hotflue gases is considerable and represents asubstantial waste of energy. This energy is partlyin the form of sensible heat due to the elevatedtemperature of the gases, and partly as latentheat in the water vapour. The latent heatamounts to around 10% of the gross calorificvalue of the fuel.

CONDENSING BOILERSCondensing boilers are designed to recovermuch of the heat in the flue gases andconsequently operate at much higherefficiencies. If the flue gases are cooled down totheir dew point - 55˚C for natural gas, 50˚Cfor diesel oil - much of the latent heat as well asthe sensible heat can be recovered. Boilersdesigned to operate in a condensing mode usecorrosion resistant materials for all or part ofthe heat exchangers and have a drain todispose of the mildly acidic condensate.

The seasonal efficiencies shown here are the meanheat to water efficiencies over the heating season withvarying boiler load. The instantaneous efficiencyindicated by commonly used combustion testequipment may be higher than theseasonal efficiency and does not takeaccount of part load losses. Allefficiencies shown here arebased on the gross calorificvalue of the fuel.

NEW GENERATION Year round condensing in all weathers: above 92% and up toCONDENSING: 99%; close to zero stack ventilation & casing losses, excellent

part load efficiency, dual fuel natural gas-diesel oil facilityCONVENTIONAL CONDENSING: Mild weather condensing; above 85% and below 92%;

low stack ventilation and casing lossesgood part load efficiency

HIGH EFFICIENCY: Non-condensing : above 80%, below 85% low stack ventilation and casing losses good part load efficiency

CONVENTIONAL BOILERS: Non-condensing boilers below the 80% platform: high stack ventilation and casing losses; poor part load efficiency

R SeriesNEW

GENERATION CONDENSING BOILERS

99%

90%

85%

80%PLATFORM

CONVENTIONALBOILERS

HIGHEFFICIENCY

CONVENTIONALCONDENSING

NEW GENERATIONCONDENSING

PLATFORM

PLATFORM

PLATFORM

Levels ofSEASONAL BOILER EFFICIENCIES

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

TECHNICAL DATA SHEET

030701

HIGH EFFICIENCY BOILER: 60˚C returnwater temperature minimum. Good designfeatures leading to 84% seasonalefficiency. Minimum sensible flue losses,low standing losses.

High EfficiencyBOILER

CONVENTIONAL BOILER operating at return watertemperature above 60˚C and flue gas temperaturesaround 200˚C. Seasonal efficiency from 60% to 70%.High stack ventilation & casing losses.

T L A N T I C

O I L E R S

S E R I E S

ConventionalBOILER

CONVENTIONAL CONDENSING BOILERwith extended or additional heat exchangerof higher quality material. For return watertemperatures below 55˚C (natural gas) or50˚C (Class D oil) - which exceeds 86% forabout two thirds of the heating season.

ConventionalCONDENSING BOILER

TERMINOLOGY

Casing loss: Heat loss from the boiler casing through radiation and convection during boiler firing and off periods.Condensate: The liquid, consisting mainly of water, formed when flue gases are cooled below dewpoint.

Dewpoint: The temperature to which the flue gases need to be cooled for condensation to occur.Gross calorific value: The heat energy of combustion of the fuel including the latent heat contained in the water vapour produced.

Latent heat loss: The heat energy contained in the flue gases emitted to atmosphere by virtue of the latent heat of vaporisation of water.Seasonal efficiency: The average heat to water efficiency of the boiler over the heating season.Sensible heat loss: The heat energy contained in the flue gases emitted to atmosphere by virtue of their elevation above ambient temperature.

Stack ventilation losses: Heat lost during boiler off periods due to the displacement of warm air in the boiler combustion chamber by the cooler ambient air as a result of natural buoyancy.Standing loss: The combination of stack ventilation losses and casing losses during boiler on and off periods.

30

25

20

20

15

15

10

10

5

50

0

Temperature (ûC)

Num

ber

ofD

ays

non-condensingfor four-fifths of

the annual energy burn

condensingfor one-fifth of the annual energy burn.

DIFFERENT MEAN DAILY TEMPS FOR LONDON

There are a great many myths stillcirculating today about the practicalityof using condensing boilers in theUnited Kingdom. The fact is that, forconventional condensing boilers, thenecessary outdoor temperatureconditions are met for at least 60% ofthe heating season in the GreaterLondon area and similar amountselsewhere in the United Kingdom.

This means at least one fifth of theannual space heating energyrequirement will be met by the boilercondensing at more the 90%efficiency and the remaining fourfifths annual space heating energyrequirement met at more than 85%efficiency. This is a saving of betweenone tenth and one third overconventional boilers.

For new generation condensingboilers using outside air forcombustion air, the whole annualspace heating energy (and any otherenergy requirement will be met by aboiler efficiency of 99%.). This is asaving of between one fifth and twofifths over conventional boilers and ofone sixth or more over conventionalcondensing boilers.

This type of condensing is termeddeep condensing and with the newgeneration condensing boiler italways takes place for all types ofenergy supply.

The UK Climate& CONDENSING BOILERS - THE FACTS

Operating Efficiency4 TYPES OF BOILER v UK CLIMATE

100

90

80

198

70

-1

60

External Temperature (ûC)

Boi

ler

Effi

cien

cyB

ased

onG

ross

Cal

orifi

cV

alue

CONVENTIONAL CONDENSING

HIGHEFFICIENCY

CONVENTIONALBOILER

NEW GENERATIONBOILER

SPECIF ICATIONAPPL ICATIONSFEATURES

l Demountable for access through most openings

l Pre-wired control panell Easy maintenance of boiler,

burner and controls

l Hotelsl Leisure Centres &

Swimming Poolsl Officesl Retail Outletsl Sheltered Housing

l 92% to 99% gcv efficiencyl High/low & modulating oil or gas controll Low NOx levels - 50ppm gas, 80ppm oill Balanced or conventional flues up to

50 metres or morel 3 BARS or more maximum working pressurel 90˚C maximum working temperature

The New Generation Condensing Boiler has two distinctheat exchangers, the first of developed quality steel designand the second of high grade plastic design. The flue gasesleave the first heat exchanger at temperatures below 90˚C,and are then extracted from the second condensing heatexchanger at temperatures always below 50˚C. Forcombustion air entry temperatures below 30˚C, efficienciesare obtained which always exceed 92% up to 99%. Theseconditions apply throughout the year in the United Kingdom.

New GenerationCONDENSING BOILER

Flue Gas Extractor

Flue Gases in suction

Flue Gases temperature25˚C- 35˚C

Main HeatExchanger

Return at60˚C

Fresh AirIntake

PolypropyleneCondenser

Pre-heated fresh air

Flue gas & boilerreturn temps within 5˚C

Control Panel

ThermalInsulation

Oil or Gashigh/low burner

110˚CTemperature limit

Condensate DrainNatural Condensate

The ATLANTIC R Series boilerIS A NEW GENERATION CONDENSING BOILERFresh air is drawn either from a balanced inlet, an external wallinlet or chimney inlet. It enters a polypropylene condensingexchanger where it is pre-warmed by the out-going flue glasses.The pre-heated fresh air is passed on to the high/low ormodulating oil or gas burner, where it is burnt with the fuel in thecombustion chamber. The products of combustion are passedthrough the main heat exchanger by the incoming fresh air and,depending on the fresh air temperature, leave the boiler attemperatures between 15˚C and 45˚C.

The ATLANTIC R Series boiler is most efficient in mid-winter whenthe heat energy requirement is at its maximum.

PERFORMANCE 15 22 40 90 150 300 400Maximum Output kW 17 22.4 41.3 90.9 153 315 460Minimum Output kW 10 14.1 25.1 54.9 95.2 150 300Dry Weight kg 150 175 275 680 980 1500 1875DIMENSIONS mm Height 1170 1348 1431 1670 1757 2147 2200Width 300 450 545 700 845 1275 1325Depth 900 1052 1431 1590 2030 2800 2850

SEECROPMARKS!

BLR

COND

BLR

COND

BLR

COND

DHW Expresso

F R

AHU flow

Rads flow

U/F flow

U/F return

Rads return

AHU return

BSV

This publication is based on Technical Appraisal 1/90 CondensingBoilers originally issued jointly by the Building Services Research andInformation Association and by Atlantic Boilers. (The original documentwas based on research sponsored jointly by the Department of theEnvironment as part of their support for the Construction Industry, byBSRIA and by Atlantic 2000.)

This leaflet outlines further development of the condensing boiler and isbased on the continuous experience of Atlantic Boilers from 1982 to date.

Ashton Under Lyne, LancashireJuly 2003

From top:R Series with constant & variable temperature circuits

R Series with radiator & DHW circuits3 x R Series boilers serving several circuits

Atlantic 2000Box 11, Ashton Under Lyne, Lancashire, OL6 7TRTel: 0161 621 5960 or: 020 7237 4912 Fax: 0161 621 5966E-mail: info@atlantic2000.co.uk Web: www.atlanticboilers.com

Heating CircuitsFOR R SERIES BOILERSThe ATLANTIC R Series boiler pipeworkrequirements are as straight forward as aconventional boiler or a high efficiencyboiler. No special circuits are required tocreate condensing.

The ATLANTIC R Series boiler fluerequirements are economic - often costcutting when compared to other boilers.Although the flue gas exit temperature islow, the volume of the gases is also greatlyreduced throughout the year as a result ofthe low gas temperatures. In addition, theATLANTIC R Series boiler has automaticspeed controlled extract fans which operatecomfortably at lowgas temperatures andpermit extensivevertical or horizontalflue ducts in low cost,carefully chosenplastic materials.