A bit o/t. Stratification in Thermal Stores

[openspaceman]

Spaceman , The occupants in your block of flats sound just like our foreign workers. All rad stats to max and windows open.

 

I used to read about centralised control district heating in the eastern bloc and I thought the practice of opening windows to control heat was just a way the bolshy masses railed against the machine, then my mate, a sqn ldr with the raf regiment told me about the problems with the married quarters in germany and how this was the only control that worked at the time. These key worker flats were occupied with principally overseas workers but they certainly were not dumb, the fault was with the system and management not understanding the time constant of a few hundred tonnes of floor.

 

I have dumb managers in my current place of work and they bring fan heaters into their offices and leave tham at 25C even when they go out, one has to experience the sheer wastefulness and environmental unconcern of utility veg management persons to lose all faith in society.

 

Any thoughts /opinion on the Navora and domestic RHI.

 

I worked for the UK agents for two makes of boilers so did not get to know others. It looks like it is derived from the original Baxi crossdraught gasifying burner but doesn't have the water cooled throat. The Baxi was a commercialisation of a research project but I cannot remember the guy's name. Anyway the big advantage of gasification is in cutting down on excess air for the secondary burn plus this one seems to have some sort of lambda feedback. For me the extra capital cost and requirements don't stack up for RHI. I live in a small 2 up 2 down cottage and the Jotul 602 keeps me warm on un paid for wood.. If I lived in a 10 bedroom mansion set in its own grounds and woodlands...

 

Evenso I'd still advocate picking upo a cheap stoker boiler from someone buying new kit to get RHI. I've seen some bargains.

 

 

2.35 kw is not going to be much use for maintaing 20 deg with windows open.

 

Yes his Esse range wasn't meant to power a full wet system.

[Stereo]

Just to clarify, we only crank the heat and open the windows to solve the damp / mold issue which is caused by the vandex tanking. I have gone into this with plasterers and plumbers at length and despite some arguing that colder would be better, this is the only thing we have found to work. We once went on holiday in October and the gas combi failed due to a leaky expansion vessel and we came back to a disgusting mess which took days to clean down. That's a separate issue and one we will solve room by room by removing the tanking in all but the lowest rooms and reverting to traditional limes etc. The bits of wall we managed to persuade them to let us just point with lime mortar have never suffered any damp issues at all. I am not consuming energy just for the fun of it. Seeing your kids sleeping next to black mold is not a good thing.

 

When asking about direct / indirect, do you mean coil vs. not a coil. In ours the Esse uses the water in the body of the store. This also circulates around the underfloor heating on demand. The flow goes in halfway up and the return is at the bottom of the store. Is this the problem? The gas combi is plumbed into a coil which is not what it was intended for but the store is a retro fit.

 

Could the Esse also be plumbed into a coil? Wouldn't that be a sealed system with the resulting issues?

 

I appreciate that the Esse is never going to heat the house and provide DHW, especially to the temps we currently require. The reason we got the store is that we wanted something that could use solar water, a wood stove, possibly a heat pump / proper wood boiler like the Eco Angus to replace the gas in future and also solar PV also in the future through the immersion heater. So all those renewable sources helping to heat the place and the immersion as ultimate backup.

 

It seems though that far from helping, the Esse is causing an issue and also, the constantly circulating water is stopping the Esse working well. The answer I suppose is to fit a laddomat so that the Esse just adds spare heat when it has it and otherwise acts as a cooker and ambient heater.

 

Perhaps I would be better looking at building a small extension to house a proper log / chip / pellet boiler and much bigger heat store and just have a wood fired rayburn for cooking / heat.

[cornish wood burner]

I fully understand your need for running the temperatures you do. What we need is to find a solution to enable you to do this.

I have previously looked at the store web site and came to the conclusion that it was direct as you say(same water).

Best answer to stop the cold water returning is a back end protection valve.(laddomat )

Your ease would in correctly then.

Solar PV through the emersion is good. I believe you can get a monitor to feed it with any surplus rather

than returning any to the grid. Expensive for 3 kw of heat to your water though.

 

In view of the fact you have a plentyful supply of wood and need the heat I think I would go down the

 

 

 

wood boiler route. Which one will need some research. One with a large wood capacity to run at night with one charge would be good. If you size your boiler correctly then gas should not be needed, possibly keep as a backup if you are away.

[cornish wood burner]

If you do go down the wood boiler route it will save you money on gas. Whether you go the cheaper route as an option suggested by openspaceman or a better quality RHI quality boiler that is up to you and your finances. Payback is something to consider, RHI might tip the balance especially in view of your high usage. If you do consider this I would get at least two quotes but give the companies an idea of the size of house, temperatures and do not forget the good ventilation. Even if you do not accept any at least you will have some opinions on heat requirement.

It might be worth considering running your underfloor directly from your new boiler and keeping the esse for dhw.

When you fit the laddomat you can plumb to the top of your store presumably.