Difference between a calorifier and a domestin indirect cylnder

[karanight]

Does anyone know the difference between a calorifier and a domestic indirect cylinder

I've been told that the calorifier is made to withstand more pressure but I would have thought that the domestic one would have to deal with as much or more pressure than a narrowboat one.

They both come fully insulated and also they can both come with twin coils

 

Edited June 29, 2015 by karanight

[Tony Brooks]

Domestic cylinders come in "grades" ( 1 to 3 I think) and the grade indicates the maximum pressure it is designed to take. I the old days the maximum pressure was about 2 metres of head from the tank in the loft so not that much pressure. Now we have direct connected hot water cylinders at least some should be designed to cope with similar pressures to a calorifier. However get it wrong and it could end up soggy and expensive.

 

Maybe Mike can put figures to what I have said. It does not help that the cylinders are often calibrated in Head while we use PSI/Bar.

[Jparry]

The figures for the domestic cylinders are grade 1 3.65 bar , grade 2 2.2 bar ,grade 3 1.45 bar

[David Schweizer]

The figures for the domestic cylinders are grade 1 3.65 bar , grade 2 2.2 bar ,grade 3 1.45 bar

 

Well those figures suggest that only grade1 might just be adequate, but only if you have a low pressure pump and a 2bar pressure relief valve. As I understand it, standard boat calorifiers are usually tested to 5bar.

[Mike Jordan]

In my experience the grade 1 domestic cylinders are not normally on the shelf and are available in a limited range of sizes.

my system is to contact Newark Copper Cylinder co who will make one to your height & diameter needs either vertical or horizontal for very little more money.

My hobby horse is the fitting of twin PRVs to reduce the chances of over pressurising your cylinder.

There is a photo in my gallery.

Mike.

[Paul C]

Every time I've looked, calorifiers are small enough for a boat and domestic cylinders are big enough for a house, the size being a huge difference.

[DHutch]

In my experience the grade 1 domestic cylinders are not normally on the shelf and are available in a limited range of sizes.

What do people fit on mains-pressure installations then, surely these are around that sort of pressure?

 

 

Daniel

[Dave Clinton]

In my experience the grade 1 domestic cylinders are not normally on the shelf and are available in a limited range of sizes.

my system is to contact Newark Copper Cylinder co who will make one to your height & diameter needs either vertical or horizontal for very little more money.

My hobby horse is the fitting of twin PRVs to reduce the chances of over pressurising your cylinder.

There is a photo in my gallery.

Mike.

Hi Mike

 

Could you link to the picture please? I'm not sure how you get to a member's gallery.

 

Also do you have a diagram for this system?

 

thanks.

[Mike Jordan]

Daniel

A domestic cylinder is fed from a tank in the house room which in turn is topped up by a ball valve rather than mains pressure.

The pressure applied is measured from the top surface of the water in the roof tank to the bottom of the cylinder.

Most cylinders are situated on the first floor and, as already mentioned only have to stand the pressure of two or three metres of head.

The grade three ones are good for up 14.5 metres of head approx., not enough for a water pump and the pressure of thermal expansion.

 

Dave

I have no idea how to post a picture from the gallery. But if you are logged in I think clicking on my avatar will show it up.

If that fails you just send me a PM and I will see if I can find the original photo to email to you.

Mike.

[Paul C]

Daniel

A domestic cylinder is fed from a tank in the house room which in turn is topped up by a ball valve rather than mains pressure.

The pressure applied is measured from the top surface of the water in the roof tank to the bottom of the cylinder.

Most cylinders are situated on the first floor and, as already mentioned only have to stand the pressure of two or three metres of head.

The grade three ones are good for up 14.5 metres of head approx., not enough for a water pump and the pressure of thermal expansion.

 

Dave

I have no idea how to post a picture from the gallery. But if you are logged in I think clicking on my avatar will show it up.

If that fails you just send me a PM and I will see if I can find the original photo to email to you.

Mike.

 

Press "More Reply Options" then "My Media" button and you can easily put them into a post.

[Tony Brooks]

Daniel

A domestic cylinder is fed from a tank in the house room which in turn is topped up by a ball valve rather than mains pressure.

The pressure applied is measured from the top surface of the water in the roof tank to the bottom of the cylinder.

Most cylinders are situated on the first floor and, as already mentioned only have to stand the pressure of two or three metres of head.

The grade three ones are good for up 14.5 metres of head approx., not enough for a water pump and the pressure of thermal expansion.

 

Dave

I have no idea how to post a picture from the gallery. But if you are logged in I think clicking on my avatar will show it up.

If that fails you just send me a PM and I will see if I can find the original photo to email to you.

Mike.

 

This certainly used to be true but I think some are now direct connected to the mains so should operate at a higher pressure. I have the feeling they may be stainless steel.

[Mike Jordan]

Thanks for that Paul, Ive just taken another route and posted the photo at the top of the forum page.

Mike.

[David Schweizer]

What do people fit on mains-pressure installations then, surely these are around that sort of pressure?

 

 

Daniel

 

I am sure MTB will correct me if I am wrong, but I am fairly certain that direct mains fed cylinders are no longer permitted under the latest instalation regulations (or whatever they are called).

[DHutch]

I am sure MTB will correct me if I am wrong, but I am fairly certain that direct mains fed cylinders are no longer permitted under the latest instalation regulations (or whatever they are called).

You need a pressure reduced, non return valve and expansion tank (as you did right back when my parents put one in over 25 years ago) but the pressure in my parents house is a good flow, as it should be, and as my house is (also mains pressure, but with a gas combi) most houses are mains pressure these days and a significant number have stored hotwater systems in preference to evil combi boxes.

 

 

####

http://www.screwfix.com/c/heating-plumbing/unvented-hot-water-cylinder/cat831112#category=cat831112&sort_by=price

UNVENTED CYLINDER (52 PRODUCTS)

Unvented hot water cylinders work directly from the mains water. An unvented hot water cylinder works on the same principles as a vented cylinder. We have a wide range of unvented cylinders in a wide selection of sizes.

 

http://www.screwfix.com/p/rm-prostel-unvented-direct-cylinder-120-litre/51564

 

RM Prostel Unvented Direct Cylinder 120 Litre £429.99 INC. VAT

Bar Pressure 3 bar

Brand RM Cylinders

Colour White

Connection Type 22mm Compression

Insulation Type High Value Insulator

Manufacturer Guarantee 25 years

Manufacturing Standards Kiwa

Model Name Prostel

Pack Size 1

Product Diameter 545 mm

Product Height 915 mm

Product Type Unvented Cylinder

Product Width 545 mm

Tank Capacity 120 Ltr

Total Product Weight 26 kg

Tested to 15bar. KIWA.

 

Presumably used with something like this:

http://www.screwfix.com/p/prv-with-gauge-15-x-22mm/41943

PRV with Gauge 15 x 22mm

Pre-set at 3bar, adjustable from 1 to 6bar. WRAS approved.

 

OR

 

http://www.screwfix.com/p/honeywell-pressure-reducing-valve-with-gauge-15mm/69396

Honeywell Pressure Reducing Valve with Gauge 15mm

Brass construction and finish. No pre-set pressure, installer can choose between 1.5-6bar. Creates constant outlet pressure regardless of fluctuating inlet rate/flow. Includes pressure gauge. Suitable for domestic use.

 

 

http://www.screwfix.com/p/ariston-pressure-reducing-valve/44939

"3.5bar pressure reducing valve. For use with Ariston Europrisma water heaters."

 

etc

 

####

 

Another tank

 

http://www.mrcentralheating.co.uk/everflo-direct-150l-unvented-cylinder?gclid=CjwKEAjw2cOsBRD3xNbRp5eQxzYSJADZGYbzKm8hDRSGSs5T5GKww0FvcJW2VIdQ0kGiVS6DPeIRvBoCnV3w_wcB#.VZGa-flVhHx

everflo stainless 150L Direct unvented hot water cylinder

£375.00 Incl. Tax

 

####

 

Could use that on a boat no issues as far as I can see, not sure about twin coil or horizontal versions?

 

 

Daniel

[peterboat]

I have just replaced the house type stainless hot water cylinder for a Newark cylinder cauliflower in copper the shape is the first thing the cauliflower is conical at both ends to help cope with higher pressure. The second thing is the weight household cyl light cauliflower heavy=thick copper I put the household cylinder in to try something out which worked then replaced it with the proper item

 

Peter

[gazza]

 

I am sure MTB will correct me if I am wrong, but I am fairly certain that direct mains fed cylinders are no longer permitted under the latest instalation regulations (or whatever they are called).

Google Range Tribune HE Duplex Stainless Steel hot water cylinders.

We have a system boiler in our house, the hot water cylinder is mains fed, the water is indirectly heated by the system boiler mych like a calorifier on your boat.

the central heating circuit is a closed loop no tanks in the loft - much like a combi boiler.

Normal working pressure is 1.5 bar

 

Nearly all modern gas fired systems in largish new build homes use a system boiler.

Smaller properties use a combi boiler.

Tanks in the loft are a thing of the past.

Edited June 30, 2015 by gazza

[Neil Smith]

I bought my marine calorifier from copper cylinder direct and was cheaper than a twin coil domestic one.

 

Neil

[NMEA]

A modern unvented cylinder is not really any different from what most boaters call a calorifier, some even have the pressure vessel we fit as a separate component as an integral feature, designed to run off mains pressure (sometimes using a pressure reducing valve) they are more than capable of operating in a marine installation, they are even available in horizontal configuration, stainless construction etc and in a wide variety of sizes. The important thing is to ensure that you get one capable of handling the pressure, which is always a published feature. The old vented ones that were used along with a loft tank for hot water pressure are an entirely different kettle of fish and should not be used, unless you put a feeder tank on your roof that is.

[karanight]

Wow, what a lot of comments. Thanks to all contributors to my question, I think after reading all the comments I'll go for the calorifier. I'm buying a new sail-away so looking at the number of comments I reckon that I'll find lots of help here, I only hope I'll be able to return all the help

[Dave Clinton]

 

 

Dave

I have no idea how to post a picture from the gallery. But if you are logged in I think clicking on my avatar will show it up.

If that fails you just send me a PM and I will see if I can find the original photo to email to you.

Mike.

 

Thanks Mike, I see what you mean now, building some redundancy into the system.

[Mike Jordan]

Yes, I think it's a shame not to double up in this instance. The extra cost is very small and may just save the

cylinder.

[Murflynn]

Does anyone know the difference between a calorifier and a domestic indirect cylinder

I've been told that the calorifier is made to withstand more pressure but I would have thought that the domestic one would have to deal with as much or more pressure than a narrowboat one.

They both come fully insulated and also they can both come with twin coils

 

why do you need to shout?

[karanight]

I don't know what this has to do with my question

I'm not shouting My eye's hurt when I use glasses and without them I can't see small print.

I always thought shouting was using CAPS.

The only way I could read your comment was to zoom in which is very inconvient

Edited July 3, 2015 by karanight