Navitron Renewable Energy and Sustainability Forum

BIOMASS => General => Topic started by: chrisenavi on August 25, 2011, 08:43:42 PM

Title: Rayburn Unvented Cylinder France
Post by: chrisenavi on August 25, 2011, 08:43:42 PM
I have read through hundreds of posts and find myself going slowly mad with conflicting information. Medication is not helping. The confusion is  further compounded by the system being in France. Any Al Murray fan knows the saying

                              "where would we be without rules?------FRANCE!!!!!!"

For reasons of cost and simplicity the existing DHW is provided by a 200L "Cumulus" electric water heater supplied with "night rate" electricity. The intention is to tap into the feed to the Cumulus and supply it with hot water from an indirect unvented cylinder of around 150L (Rayburn recommend around 130L) heated from a wood burning Rayburn. All the DH(and C)W is at 3 Bar. This is to replace the copper cylinder that split due to the overpressure from the incoming cold water feed. Apparently it was working fine last winter until the grade 3 copper cylinder split and belled out due to the pressure in the DHW, at that point the owner asked me to have a look and see what could be done to fix it.

The Rayburn is connected to five rads pumped using an injector T into the 28mm gravity loop to the cylinder controlled by a pipestat on the return leg. The gravity/rad system is connected to a 25L F & E tank in the roof space. There is a rad connected across the 28mm F & R gravity loop as a heat dump

In line with French rules unvented is not standard practice but obviously the Rayburn must be vented. The unvented part of the system will be protected by temperature and pressure relief valves and an 18L expansion vessel.

Could those who really know please make comment and or suggestions as to how safe this configuration is, how to change it etc...

Title: Re: Rayburn Unvented Cylinder France
Post by: gb484 on February 07, 2012, 06:15:14 PM

Modify a cumulus tank to install a heat exchanger circuit as in the above post. apper solaire is a fantastic forum and well worth browsing for similar ideas. Hope this helps, gb.

Title: Re: Rayburn Unvented Cylinder France
Post by: gb484 on February 07, 2012, 06:22:56 PM

As I said, well worth a browse, just found this one. This is probably the exact sort of tank that you've got.