Large house combi v system boiler?

Discussion in 'Plumbers' Talk' started by Naesure, May 26, 2008.

  1. Water Systems

    Water Systems New Member

    I don't install boilers or heat banks or unvented. I
    install whole bathrooms

    A bathrooom changer!!!! :) But he know all the answers about pressures and thermal systems. Wow!!! What a belly laugh! Keep 'em comin'!
     
  2. tgs

    tgs New Member

    I don't install boilers or heat banks or unvented.
    I
    install whole bathrooms

    A bathrooom changer!!!! :) Good at tiling are
    you? :) But he know all the answers about pressures
    and thermal systems. Wow!!! What a belly laugh! Keep
    'em comin'!

    That's the best you can do is it?
     
  3. Water Systems

    Water Systems New Member

    Well, as said 'Naesure' with combi's there are pros &
    cons.
    Combi's are sized on there HW output & most of the
    larger condensing combi's require high gas pressure &
    flow rate at the appliance, which may result in a
    meter change & up too 35MM as service
    pipe...etc..etc.

    I know no domestic combi that requires a U16 meter. Only if you keep gas fires and other unnecessary stuff will that result.

    But really for a larger domestic installation like
    yours, storing hot water is the optimum system and
    with the incoming mains pressure/flow permitting, an
    unvented cylinder will give your good pressure &
    simaltainious use of appliances.

    But expensive!! And big!!!! And large combis store water to!! Try looking at a high flow Rinnai multi-point that can be fitted outside.
     
  4. Water Systems

    Water Systems New Member

    I don't install boilers
    or heat banks or unvented.
    I install whole bathrooms

    A bathrooom changer!!!! :)
    Good at tiling are you? :) But
    he know all the answers about
    pressures and thermal systems.
    Wow!!! What a belly laugh!
    Keep 'em comin'!

    That's the best you can do is it?

    What a let down. We were expecting more fun from you.
     
  5. Captain Leaky

    Captain Leaky New Member

    Walter, how do you manage to keep spouting drivel all day and all night?

    Do you actually have a job?

    Do you know anything at all?

    Or are you just a sad old troll?
     
  6. tgs

    tgs New Member

    What a let down. We were expecting more fun from you.

    That's just what we were expecting from you.

    It obviously would be too much expecting you to actually show that you understood anything about all the things you cut and paste.

    It still puzzles me that someone who says he is a graduate is lacking in even the most basic ability to analyse systems. Not to mention your inept maths and your complete inability to read.

    No, you just keep prattling on and give us all a good laugh.
     
  7. Captain Leaky

    Captain Leaky New Member

    and on and on and on... :^O
     
  8. Mr Ian

    Mr Ian New Member

    That's it WS, go and plumb in the garden too!

    It might interest you to know that the return temp of a heat store is far too hot for the boiler to condense efficiently - between 35c and 60c is very efficient.

    You might RECOVER MORE energy than at 60c, but that's because you're also WASTING MORE energy to start.

    Anyone with a brain could figure out that the hotter the return temp and the gas going through the flue the more energy is being wasted. Which is why I have explained it for you.
     
  9. Water Systems

    Water Systems New Member

    What a let down. We were expecting more fun from
    you.

    That's just what we were expecting from you.

    Yo disappoint!
     
  10. Water Systems

    Water Systems New Member

    Walter, how do you manage to keep spouting drivel all
    day and all night?

    Do you actually have a job?

    Yes, but I don't tile bathrooms.
     
  11. Captain Leaky

    Captain Leaky New Member

    Walter, how do you manage to keep spouting drivel all
    day and all night?

    Do you actually have a job?


    Yes, but I don't tile bathrooms.


    No

    That would require hard work, skill and application... tiles don't stick themselves to the wall by yakking rubbish at them
     
  12. HOTDOG ø

    HOTDOG ø Active Member

    The only thing around here that is dangerous when unvented is dear old Walter.

    Imagine if all that hot air was left shut in....KABOOM..it would make a great clip on Youtube.
     
  13. Water Systems

    Water Systems New Member

    That's it WS, go and plumb in the garden too!

    It might interest you to know that the return temp of
    a heat store is far too hot for the boiler to
    condense efficiently - between 35c and 60c is very
    efficient.

    Totally WONG!!!!

    MAINLY CONDENSING OPERATION

    If a whole bath is run off and the store temperature is around 10C, the boiler will raise that water say 35C to 40C emerging from the flow pipe - the temperature rise of the boiler. 10C returning to the boiler will guarantee high condensing operation. <u>Even if the condensing boiler is set to 80C, 80% of reheat time will be in condensing mode</u> and even more if set to 70C to 75C. The initial 1/3 of re-heat is highly efficient.

    At return water temperature of 30C, 70% to 80% of latent heat is recovered. At 35C only 50% is recovered. A big difference in efficiency for only 5C return water difference. The thermal layering of a thermal store and the plate Heat X pumping water into the bottom of the cylinder less than 30C, ensures that when in operation the boiler is highly efficient recovering more latent heat than a condensing boiler directly coupled to a rad circuit and a coiled cylinder.

    LARGE BOILERS CAN BE USED WITHOUT ADVERSE EFFECTS
    A 70kW condensing boiler can be coupled to a direct store using 28mm pipes. This will give a high temp rise and ultra quick recovery.

    DHW ENSURES VERY COLD CYLINDER BOTTOM
    The modulating DHW pump ensures only very cold water returns to the cylinder. This gives a very cold spot at the bottom of the cylinder. This cold water then is pumped directly into the boilers return when the boiler is called.

    SCALE RESISTANCE
    The plates on the plate heat X flex and scale build up reduced. Scale is only a real big problem in excessive hard water areas like Reading.

    THERMAL LAYERING DOES IT
    Thermal store heat banks (with plates heat Xs) set to 70C give very acceptable DHW performance and condense <u>very well</u>. Thermal layering does it all for you. <u>Get to understand thermal layering</u>. The top of a cylinder can be 80C and the bottom 20C. The boiler is in the most ideal hydraulic environment enhancing efficiency, giving high condensing efficiency and boiler longevity, always having full flow through the boiler

    BOILER CYCLING ELIMINATED
    Heat banks eliminate boiler cycling which can be very inefficient in thermal heat loss and burner start up. The vastly reduced stress on controls gives boilers a long life. Very neat indeed. If a preheated combustion air boiler is used, tertiary heat exchanger, cycling can reduce the high efficiency of these boilers. Continuous operation for as long as possible improves boiler efficiency and thermal stores do that.

    Now you know. You can now tell your mates in the pub.
     
  14. Water Systems

    Water Systems New Member

    Walter, how do you manage to keep spouting drivel
    all
    day and all night?

    Do you actually have a job?


    Yes, but I don't tile bathrooms.


    No

    That would require hard work, skill and
    application... tiles don't stick themselves to the
    wall by yakking rubbish at them

    I am sure you have talked many a tile onto the wall.
    What is your grouting like?
     
  15. Axelbobo

    Axelbobo New Member

    Worse than children you lot!
    I bet the OP must be having a nervous breakdown by now!
     
  16. Brid

    Brid New Member

    It would be foolish to offer 'educated' advice as I have not visited your property (unlike some on this site). So i would like to offer you some food for thought. WB Highflow 440 or a good unvented system, why not? But, I have worked on a large property in the past and fitted 2 combi's, 1 for the upstairs and 1 for the downstairs, both on their own programmers, making quite a versatile set-up. My own WB 37CDI manages well in a 1925, 4 bedroom, 2 showers and 1 bath. 2 adults & 3 kids. Do as one wise person as already said, get 3 or 4 people round to give you advice and quotes, then make your decisions After all you may be stuck with it for the next 10 years!
     
  17. Captain Leaky

    Captain Leaky New Member

    Do as one wise person as already said, get 3 or 4 people round to give you advice and quotes, then make your decisions After all you may be stuck with it for the next 10 years!

    Quite ;)
     
  18. Mr Ian

    Mr Ian New Member

    That's it WS, go and plumb in the garden too!
    If a whole bath is run off and the store temperature
    is around 10C

    You don't even know your own product you're trying to recommend?!? The store will never hit 10c because to do so the user would have to have been running lukewarm water out of his hot water taps for the last 20 mins.

    Perhaps that's what heat bank customers do - think "I need some water at 10c, I'll just switch the hot tap on and wait for the water to cool".

    Then you go and say "LARGE BOILERS CAN BE USED WITHOUT ADVERSE EFFECTS". If I wanted a large boiler I'd get a highflow combi. Thanks for a completely useless benefit, like most of the others.

    Perhaps we can end this conversation with a quick trivia question:
    Q. What heating product is commonly referred to as a "sludge bucket"?

    You can see 'em queuing up to buy one :)
     

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