Could anyone give me advise on the good and bad points of the Megaflow system and whether it is better than the conventional water tanks. Many thanks.
Jeeves
Jeeves
jeevesy2000 said:Could anyone give me advise on the good and bad points of the Megaflow system and whether it is better than the conventional water tanks. Many thanks.
Jeeves
Water Systems said:Thermal Stores/Heat Banks are far superior than unvented cylinders - and safer. Read below....
Advantages of Thermal Stores/Heat-Banks
- Instant high pressure hot water - When the store has reached temperature water is delivered instantly at the taps.
- High mains water pressures - At up to 10 bar, compared to 3.5 bar maximum with most unvented cylinders.
- Very high water flow-rate - The high-end heat-banks have a flow-rate up to 45 litres/min.
- Long efficient boiler burn - Eliminates boiler on-off cycling increasing efficiency and boiler longevity.
- May combine the output of the stored water and the boiler - The boiler and energy in the store may be combined to increase output.
- Cylinder may be smaller for a similar performance - smaller cylinders than unvented cylinders.
- Cylinder at low pressure - Unlike an unvented cylinder vented stores do not store water at high pressures.
- Legionella bacteria virtually eliminated - The Legionella bacteria cannot survive in the high temperature sealed conditions of a heat-bank.
- No scale build-up in heat-bank – Containing primary and not secondary fresh water, there is no scale build-up inside the heat-bank cylinder.
- Cold water storage eliminated - No need for cold water storage tanks.
- Stored water vessel need not be cylindrical – As no internal coil is used for hot water heat transfer the stored water vessel may be any shape, as opposed to a thermal store which has to be cylindrical for maximum
efficiency. This has advantages where space is limited.
- No Annual Service Charge – Unvented cylinders require an annual service of between £60-£100. Thermal stores and Heat Banks are service free.
- Thermostatic Radiator Valves can be on all Rads - No wall thermostat required and TRV s on all rads when the CH circuit is take off the store cylinder and an auto modulating speed Grundfos Alpha pump used.
- Cheaper Smaller Boilers May Be Used – The large buffer of stored water means that a boiler sized for average use, not peak use, can be fitted.
- Larger Boilers may Be Used Without Fear of Boiler Cycling – A larger boiler can be used to reduce the cylinder size or give rapid heat recovery rates or both.
- Full Electric Backup of CH and DHW – An immersion Heater(s) can be fitted in the cylinder that will give CH and DHW backup very cheaply.
- Vented Thermal Stores/Heat Bank Eliminate Explosion risk – Unvented cylinders have an explosion risk. This is not a problem with vented thermal stores/heat banks.
http://www.waterheaterblast.com
- Pressurised Thermal Stores Don't Need Annual Service - No BBA unvented certification for fitting or annual service is required if a thermal store is pressurised and uses a plate heat exchanger.
And an annual service charge by law. So, have it 25 years and that may be £2,500 at todays rates (more as inflation takes hold) just to have a cylinder of hot water in your house
.............. Don't go on old wives tales.
ididdidi said:Hi Guys I have fitted dozens of thermal stores all replacements for failed units, I am also Unvented approved. If it was for myself, Unvented every time if you know anything about the hard water in lincolnshire you will know it eats thermal stores in months although that may not be the main problem, filthy heating circuits and undersized expansion I believe is the main culprit but hey everyone has an opinion cheers
ididdidi said:My My you are the feisty one, as I said everyone has an opinion and mine is as valid as yours.
Water Systems said:ididdidi said:My My you are the feisty one, as I said everyone has an opinion and mine is as valid as yours.
I am not interested in opinions in any way whatsoever. I go by facts and intelligent analysis, not arm waving or what the fellas said down the caff.
The problem is that far too many people are out there knowing sweet FA, with little intelligence to analyse what is in front of them.
Why is it that so many of your posts start with "It is clear", when the only really clear thing is that you write nonsense and won't listen to anyone?Water Systems said:It is clear you need to know more about...
Hm. Like that's going to happen.What you don’t understand come back to me.
oilman said:Thermal Stores/Heat Banks are far superior than unvented cylinders - and safer. Read below....
Advantages of Thermal Stores/Heat-Banks
- Instant high pressure hot water - When the store has reached temperature water is delivered instantly at the taps.
No different from unvented then. Hot water is NOT available instantly at the taps, you have to flush the cold from the pipe first.
- High mains water pressures - At up to 10 bar, compared to 3.5 bar maximum with most unvented cylinders.
3.5 bar is adequate, and results in less wasted water. What are you going to do when you don't have 10 bar anyway? as most places don't.
- Very high water flow-rate - The high-end heat-banks have a flow-rate up to 45 litres/min.
Big deal
- Long efficient boiler burn - Eliminates boiler on-off cycling increasing efficiency and boiler longevity.
Store is maintained at a higher temperature so wasting fuel.
- May combine the output of the stored water and the boiler - The boiler and energy in the store may be combined to increase output.
Shoved down the usual 22mm pipe, it will be a pointless increase.
- Cylinder may be smaller for a similar performance - smaller cylinders than unvented cylinders.
Only if the temperature is higher. You are dealing with HEAT
- Cylinder at low pressure - Unlike an unvented cylinder vented stores do not store water at high pressures.
You said earlier it was only 3.5 bar.
- Legionella bacteria virtually eliminated - The Legionella bacteria cannot survive in the high temperature sealed conditions of a heat-bank.
Please tell me where I can get some of these. I do not know the figures for people dying from legionaires' disease conracted from domestic water supplies.
- No scale build-up in heat-bank – Containing primary and not secondary fresh water, there is no scale build-up inside the heat-bank cylinder.
Really? Depends on construction.
- Cold water storage eliminated - No need for cold water storage tanks.
So why is this different from an unvented cylinder?
- Stored water vessel need not be cylindrical – As no internal coil is used for hot water heat transfer the stored water vessel may be any shape, as opposed to a thermal store which has to be cylindrical for maximum efficiency. This has advantages where space is limited.
Do you mean thermal store?
- No Annual Service Charge – Unvented cylinders require an annual service of between £60-£100. Thermal stores and Heat Banks are service free.
But then unvented cylinders don't get annual services, and Thermal stores do require attention in my experience.
- Thermostatic Radiator Valves can be on all Rads - No wall thermostat required and TRV s on all rads when the CH circuit is take off the store cylinder and an auto modulating speed Grundfos Alpha pump used.
Building regs require a room stat.
- Cheaper Smaller Boilers May Be Used – The large buffer of stored water means that a boiler sized for average use, not peak use, can be fitted.
Boiler costs vary little with size compared with the system cost.
- Larger Boilers may Be Used Without Fear of Boiler Cycling – A larger boiler can be used to reduce the cylinder size or give rapid heat recovery rates or both.
Make your mind up.
- Full Electric Backup of CH and DHW – An immersion Heater(s) can be fitted in the cylinder that will give CH and DHW backup very cheaply.
As with unvented cylinders.
- Vented Thermal Stores/Heat Bank Eliminate Explosion risk – Unvented cylinders have an explosion risk. This is not a problem with vented thermal stores/heat banks.
http://www.waterheaterblast.com
But with the 7 safety devices on an unvented cylinder the risk is negligible.
- Pressurised Thermal Stores Don't Need Annual Service - No BBA unvented certification for fitting or annual service is required if a thermal store is pressurised and uses a plate heat exchanger.
Yes they do, all pressurised systems are covered by BS7041.
doitall said:Water Systems said:ididdidi said:My My you are the feisty one, as I said everyone has an opinion and mine is as valid as yours.
I am not interested in opinions in any way whatsoever. I go by facts and intelligent analysis, not arm waving or what the fellas said down the caff.
The problem is that far too many people are out there knowing sweet FA, with little intelligence to analyse what is in front of them.
Like a group of people setting up a tank and launching it into space about what you would expect from the Yanks.
The film makers admit it was set-up WS, in this country it cannot and will not happen.
Softus said:Why is it that so many of your posts start with "It is clear",Water Systems said:It is clear you need to know more about...
And yet...Water Systems said:I never insult people.
Water Systems said:This one is thick.
Water Systems said:Thicko, they don’t.
Water Systems said:Read again. You are a thicko.
Water Systems said:Read again. You are a thicko.
Water Systems said:Thicko, unvented cylinders do not provide CH.
Water Systems said:Will not happen!!! What a pillockl!!!!
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