Difference between revisions of "Central heating design"
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== Pipework == | == Pipework == | ||
| − | + | === pipework materials === | |
| − | + | ==== plastic ==== | |
| − | + | ===== barrier v. non-barrier ===== | |
| − | + | Conventional Wisdom is that only barrier pipe should be used for CH systems as the metallic barrier layer prevents oxygen diffusing throug the plastic walls of the pipe into the primary water and causing corrosion in ferrous and possibly other metallic parts of the system - boilers, radiators etc. However Hepworth Plumbing Products have stated [[http://groups.google.co.uk/group/uk.d-i-y/tree/browse_frm/thread/70540dffa9cf9f4b/34103c153f976739?rnum=1&q=If+Hep2O+Standard+pipe+has+been+installed+in+accordance+with+our&_done=%2Fgroup%2Fuk.d-i-y%2Fbrowse_frm%2Fthread%2F70540dffa9cf9f4b%2Fe2db7ffcad95adb1%3Flnk%3Dst%26q%3DIf+Hep2O+Standard+pipe+has+been+installed+in+accordance+with+our%26rnum%3D1%26#doc_e2db7ffcad95adb1]] | |
| + | [[http://groups.google.co.uk/group/uk.d-i-y/tree/browse_frm/thread/ff1a4f63c1facf9e/4254068524cd8c4c?rnum=1&q=hepworth+barrier+pipe&_done=%2Fgroup%2Fuk.d-i-y%2Fbrowse_frm%2Fthread%2Fff1a4f63c1facf9e%2Ff343d48ec0be74b2%3Flnk%3Dst%26q%3Dhepworth+barrier+pipe%26rnum%3D2%26#doc_f343d48ec0be74b2]] | ||
| + | in the uk-d-i-y newsgroup that: | ||
| + | <blockquote> | ||
| + | If Hep2O Standard pipe has been installed in accordance with our | ||
| + | instructions in a central heating system and one of the recommended | ||
| + | inhibitors used there is no technical reason why it should not continue to | ||
| + | give good service for many decades. | ||
| + | </blockquote> | ||
| + | and | ||
| + | <blockquote> | ||
| + | It is now considered by British Gas that central heating systems that | ||
| + | include plastics pipe manufactured to the appropriate British Standard | ||
| + | (such as Hep2O) do not represent a potential corrosion problem from | ||
| + | oxygen ingress where the system water includes an adequate strength of | ||
| + | inhibitor. This applies equally to Barrier and Non-Barrier pipes. | ||
| + | </blockquote> | ||
| − | + | ||
| − | + | ==== copper ==== | |
| − | + | ||
| − | + | ||
| − | + | === pipework layout === | |
| − | + | ==== pipe sizes v. heat-carrying capacities + noise ==== | |
| + | ==== microbore ==== | ||
| + | easy install + balancing | ||
| + | ==== tree + branch ==== | ||
| + | ([28]-22-15-[10/8]) - good for balancing | ||
| + | ==== dual loop ==== | ||
| + | inherently balanced but rarely practicable | ||
| + | ==== random ==== | ||
| + | bad for balancing but sometimes necessary | ||
== Installation == | == Installation == | ||
Revision as of 17:20, 13 January 2007
Article about designing CH systems.
Heat requirements
- Discuss + links to whole-house heatloss calculators
- Discuss + links to energy conservation articles
Heat Sources
- single source
- gas or oil boiler
Discuss types of boiler, combi/conventional choice etc asper Ed's Boiler Choice FAQ with additional discussion of- combined range+boilers
- CHP (Microgen, Whispergen)
- electric
- peak rate v. off-peak
- standalone electric boilers
- thermal store
- gas or oil boiler
- multiple sources
- sources (additional to above):
- ranges (Aga, Rayburn etc) with back boiler
- wood burner with back boiler
- solar thermal hydronic
- ground source heat pump
- combining sources:
- thermal store
- neutral-point mixing things
- controls
- sources (additional to above):
Heat Emitters
- radiators
- output specifications Delta-50 and Delta-60
- locations wrt heat losses - under windows v. inside walls
- fan-assisted e.g. kickspace
- underfloor
- other radiant e.g. in wall, in ceiling (I kid you not!)
Controls and Zoning
- Zoning
- Y-plan, S-plan, pump-plan
- Timers, programmers, thermostats, programmable thermostats
- location of thermostats
- hall or living room - no external heat sources
- location of thermostats
- TRVs
- mixed rads + UFH layouts
- On/Off v. proportional control (aka Digital v. Analogue)
- Feedforward aka weather compensation etc
Pipework
pipework materials
plastic
barrier v. non-barrier
Conventional Wisdom is that only barrier pipe should be used for CH systems as the metallic barrier layer prevents oxygen diffusing throug the plastic walls of the pipe into the primary water and causing corrosion in ferrous and possibly other metallic parts of the system - boilers, radiators etc. However Hepworth Plumbing Products have stated [[1]] [[2]] in the uk-d-i-y newsgroup that:
If Hep2O Standard pipe has been installed in accordance with our instructions in a central heating system and one of the recommended inhibitors used there is no technical reason why it should not continue to give good service for many decades.
and
It is now considered by British Gas that central heating systems that include plastics pipe manufactured to the appropriate British Standard (such as Hep2O) do not represent a potential corrosion problem from oxygen ingress where the system water includes an adequate strength of inhibitor. This applies equally to Barrier and Non-Barrier pipes.
copper
pipework layout
pipe sizes v. heat-carrying capacities + noise
microbore
easy install + balancing
tree + branch
([28]-22-15-[10/8]) - good for balancing
dual loop
inherently balanced but rarely practicable
random
bad for balancing but sometimes necessary
Installation
- routing
- installation in solid floor
- joist notching
- drain-off points
- plastic v. copper or chromed pipetails
- play in tails
- pressure testing
- flushing