Domestic Hot Water Systems

From DIYWiki
Revision as of 04:08, 30 August 2007 by 91.188.164.75 (talk)
Jump to navigation Jump to search

tv color lcd 37 sharp hp procurve 2824 incd cd rw gigi finizio ti cerchero real pleyer trasmissione video senza fili abbigliamento accessorio miss italia it la donna cannone file per fun 4 maletic joe lansdale dissipatore 754 silent micro onde sony sdm-hs75pb file rar egle vitamina x blay blade ripetitore segnale con telecomando holly e benji gem boy lavastoviglie scomparsa totale shift thefuture vis phate scatman holidays ethernet scheda pcmcia culi nudo nudo a920 sistema home theater www poltronesofa it rs 125 aprilia haiduci gabry ponte ucas kaon emu toner epson al-c2000 maglia a v voli nizza google nel web auto seminuove godwin austen tuttowrestling sesso in pubblico ariston incasso aaa regina elisabetta prestito otranto garbo greta case in vendita a giussago jotuni, maria insieme kar maxtor 40 gb ata uomo tigre 2 porsche 996 4s nero lettori dvd majestic the game. the documentary satellite heaven suonerie sansung camilo sesto video post com janusz haka elicotteri e ten spinning fitness sesso con animali gratis ticino trasporti film eva henger da scaricare gratis coded arms si presenta online eagle eye cherry tamburellisti torrepaduli philips 17 monitor www geox com sexi chat vini dolci liquori 1998 naked adrian mutu goal famosi anche la notte del corvo in italiano settimanale chi ascoltare canzone beny benassi satisfaction mp3 jinotega acer router parata d eroi pellegrino vicenza auto giornale bella it www theclub it niurka fotos palyboy dell tanto la queria de andy y lucas hard 50 evgenia dvoretskaya minolta fotocamere mary kate and ashley olsen pictures villaggio turistico formentera alcor catanzaro dvd r vendita piedi con calze video nebulizzatore ultrasuoni heverlee kalimba no me quiero lora della furia roma vienna passo falso furukawa dia contra el mac donals rai algerien played alive di safri duo endocrinologia pediatrica teseo agguato nella jungla condizionatore portatile classe a lcd al1715 ragazza volterra lady sexy seduta sopra la faccia web marketing tools lotta per la vita sfondi samsung sghe700 monitor samsung syncmaster 193p ups t700 suttner, bertha von- palmari windows amarte es mi pecado alessandra rosaldo y racconti sculacciate semo romani frasi sulla vita il pilota del danubio lg l1710s 17 tft www nokia imagin una borsa piena di guai provincia di pordenone amilo pro v7010 fujitsu-siemens paperino operazione eamonn rapti danze sacre bon jovi have a nice ho diritto al piacere slot 1 32 solo di emon il testo ferrari 360 spider cantautore legge tognoli zagarise walker texas ranger progettista meccanico (regione emilia romagna - bologna provincia) sdm hs95 cucardas km0 mitsubishi pajero sport auto km 0 woyeur free vacanze appartamenti ostuni combo lettore dvd vcr prodotti lierac seno privata sala real estate chat c6 bela office access 2003 ironmaiden condono edilizio in toscana televisori 33 vacanze mare italia cartina geografica dell adige hot parede heart s on fire john cafferty ultimo cd degli u2 aggiornamento veloce sulle tecnologie degli attual whats the wrong don t leave home dido rolling stones angy km0 fiat panda diesel auto km 0 vendo cuccioli cane maltese he i believe pocket kingdom derattizazione su firenze kzj 95 achternbusch, herbert casio exilim pro exp600 lindalovelace viita, lauri dvd recorder - r dragonball immagini diaz, bartholomeu sl 150 cordless copertina ascolta pooh etienne guesh patti ave ninchi tuta sci bambino big girls my bend traduzione mirage studentessa piu sexy poste contratti collettivi la mia vita comincia in malesia foto attori www sussidiario it philips televisori plasma pixel plus rav4 2002 il prezzo del pericolo dual voltage rs-mmc 512mb max pane europe cherry www mamamedia com There is a wide and potentially bewildering variety of systems for supplying hot water in houses and flats (Domestic Hot Water or "DHW"). These include

  • Conventional systems with a large tank in the attic and a hot water cylinder
  • Combi Boilers
  • Unvented (e.g. Megaflo)
  • Thermal Stores or Heat Banks
  • Solar Hot Water systems
  • Gas multipoint heaters (like old Ascot types)

and more ....

This document aims to explain the principles underlying the different types and why one would choose one rather than another. In particular the various types of mains pressure systems - unvented and thermal stores/heat banks - becoming increasingly common in the UK are discussed, as are solar and other renewable systems.

This article describes the main features of DHW systems and explains terms used in describing such systems. Further articles will give more details on particular varieties of system, including some hybrid systems combining elements of the basic types discussed here, discussion of some commercial and other systems available, and links to suppliers' web sites and other resources.

Main types of DHW system

The main differences between types of DHW systems are:

  • Instantaneously heated e.g. combi boilers, multipoint ('Ascot'-type) instantaneous gas water heaters, instantaneous electric water heaters

versus

  • Stored heat e.g. systems with some sort of hot water cylinder

and

  • Mains pressure water e.g. combi boilers, unvented ('Megaflow' type) cylinders

versus

  • Low pressure with stored water e.g. conventional: tank in attic and hot water cylinder in airing cupboard

The pros and cons of these systems are:

PRO CON
Instantaneous
  • Continual supply of hot water.
  • Rate of supply limited by fuel supply/consumption. No backup when heater (e.g. combi) fails.
Stored heat
  • Potentially very high rate of supply of hot water.
  • Can accomodate backup heating (e.g. electric immersion for gas boiler) and multiple heat sources (e.g. solar gas).
  • Supply runs cold when stored heat exhausted: takes time to re-heat.
  • Heat lost from store while not in use.
Mains pressure
  • 'Dry loft': no need for tank in attic.
  • Good pressure for showers