Jump to content

Webasto and Calorifier sizing


Featured Posts

1 hour ago, Tacet said:

What does the temperature difference need to be to achieve a 5kW transfer? 

Not sure, I assume they're rated with a hot output from the boiler into a cold tank -- maybe 50C difference? (I expect there's a standard spec for this).

 

I do know the coil surface area is 0.6m2 per coil (including fins) which is a lot bigger than a standard one, also the coil pipes are bigger diameter (22mm?).

Link to comment
Share on other sites

43 minutes ago, IanD said:

Not sure, I assume they're rated with a hot output from the boiler into a cold tank -- maybe 50C difference? (I expect there's a standard spec for this).

 

I do know the coil surface area is 0.6m2 per coil (including fins) which is a lot bigger than a standard one, also the coil pipes are bigger diameter (22mm?).

Mine is 22mm but I don't think its finned. I went for 22mm as I was going to thermosyphon the Dickinson through it, but changed that setup.

Link to comment
Share on other sites

31 minutes ago, Colin Brendan said:

Does anyone put the calorifier in series? I know it's often ill advised, but if it's 22mm (and maybe with an optional bypass) - or are you just causing other convection problems doing that?

 

In series with what?

 

If you mean the rads then apart from a longer warm up I can't see why it would not work. I doubt it would be easy to get gravity circulation if you did that, but as you seem to have a pumped system it should work, but what you hope to achieve I don't know.

Link to comment
Share on other sites

26 minutes ago, Tony Brooks said:

 

In series with what?

 

If you mean the rads then apart from a longer warm up I can't see why it would not work. I doubt it would be easy to get gravity circulation if you did that, but as you seem to have a pumped system it should work, but what you hope to achieve I don't know.

 

Mine will be in series -- calorifier first, rads second -- to give the fastest possible water warm-up time with shortest generator/boiler running time when the demand is for hot water only, when all the water goes through the calorifier.

 

For this to work without a bypass you need a big heat source as well as a big coil calorifier, otherwise it would take too long for the rads to heat up when you also want heating. My boat will have this, both diesel pressure-jet boiler and generator can push about 10kW of heat into the (pumped) system (with 5kW calorifier coils), but most boats don't so a bypass would be needed for when you want quick radiator heating, then some of the hot water goes straight to the rads and some through the calorifier.

 

This solution should work for me but most people will need something different, you need to design the system based on your particular requirements not "one-size-fits-all"... 😉

Link to comment
Share on other sites

  • 1 month later...
On 27/01/2023 at 16:47, ditchcrawler said:

In the warm yes, well insulated, not as good as it could be. I really should get a can of spray foam.

I don't think so, after my little leak I have removed stuff from the cabinet so I can check every few days. I have had a warm shower this a.m. using heat from back boiler, the engine tends to make the water too hot before bedtime.

Link to comment
Share on other sites

56 minutes ago, LadyG said:

I don't think so, after my little leak I have removed stuff from the cabinet so I can check every few days. I have had a warm shower this a.m. using heat from back boiler, the engine tends to make the water too hot before bedtime.

But I don't have a leak and if I did I would fix it. there are several non insulated areas where pipes connect to the calorifier which I really should have coated up at the time, not just hand a round tuit on them

 

Link to comment
Share on other sites

1 hour ago, ditchcrawler said:

But I don't have a leak and if I did I would fix it. there are several non insulated areas where pipes connect to the calorifier which I really should have coated up at the time, not just hand a round tuit on them

 

Oh but I have a warm dry boat, all the time, and it's warm almost the full cabin length even when the temp outside is -6C. Ad lib hot water 24/7 in winter, and in summer I tend to cruise every few days so have plenty of water for showers and laundry. It's no big deal removing stuff from round my calorifier, I keep my standby windlass handles there, and the C&H spike.  Things that are rarely used. I'm very glad of all the uninsulated pipework, it keeps the boat warm and dry, bed niche is perfect temperature, I can see the point of insulating pipes in a house, but not on a boat, unless it is unattended for weeks in the depths of winter.

 

 

 

 

 

 

Link to comment
Share on other sites

47 minutes ago, LadyG said:

Oh but I have a warm dry boat, all the time, and it's warm almost the full cabin length even when the temp outside is -6C. Ad lib hot water 24/7 in winter, and in summer I tend to cruise every few days so have plenty of water for showers and laundry. It's no big deal removing stuff from round my calorifier, I keep my standby windlass handles there, and the C&H spike.  Things that are rarely used. I'm very glad of all the uninsulated pipework, it keeps the boat warm and dry, bed niche is perfect temperature, I can see the point of insulating pipes in a house, but not on a boat, unless it is unattended for weeks in the depths of winter.

 

 

 

 

 

 

I didn't say pipes, I said calorifier. You probably realise how bad the heat loss is as the round tuit has been on it for 22 years

Link to comment
Share on other sites

On 29/03/2023 at 12:50, ditchcrawler said:

I didn't say pipes, I said calorifier. You probably realise how bad the heat loss is as the round tuit has been on it for 22 years

I know what you were advising, I don't want more insulation as the cupboard is warm and dry so I can keep some bedding etc above the calorifier to keep dry,  hang socks etc after hand washing. Some  heat does radiate in to the boat, so it's never really cold in that area.

The water in the calorifier is better to be warm enough to shower and to wash dishes, but not too hot to do so. The back boiler keeps the calorifier warm 24/7. The calorifier is not naked, it has a bit of foam round it, I think it is added by manufacturer, I thought they were all like this?

Edited by LadyG
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.