Orlan Super 25Kw + Akvaterm 2000 litre installation blog

[Fiddlers]

Hi all, today saw the first steps of our wood burning future. Took delivery of a 2000l Akvaterm on Friday and a 25Kw Orlan Super log boiler today. I'm planning to use this post as a blog of how we get on installing and running this system in the hope it's useful to others!

First up are picture of the structural modifications I had to make to the garage where the boiler and tank are going to live. The truss tie beams gave a ceiling height of 2m and the tank is 2.1m -ish. I raised a few beams up by 200mm at the front of the garage to give 2.2m clearance. New bolts and timber connectors made a good looking job.
Note the reinforcing timbers I added to the tank pallet - the 3 tank legs only just sat on the palette and the timber started bowing. I'm not sure of the best way to move these tanks but we ended up with 4 people "walking" it a few inches at a time across some 18mm ply till it was on the concrete. Moving the boiler was fun. Using an engine crane doesn't work - it's just not possible to get the loading properly without squashing the side walls. We ended up hiring a pallet truck and building some suitable ramps to get it in since there's a small step from the drive to the garage.

The tank has two DHW coils, one top and one bottom for preheat. We removed the coils from the tank to reduce the weight a bit. In hindsight this probably helped a bit but getting them back in is very tricky. I suspect the factory either has a special tool or drops them in with the tank on its side. We have two additional hatches in this tank since I want to future proof as far as possible. I'd recommend having one spare hatch regardless as Akvaterm suggest an annual inspection and I don't fancy removing those coils again!

[Fiddlers]

If you've ever wondered what the inside of an Akvaterm looks like here's your chance! 
My 4 yr old got very excited when the wraps came off - "Daddy, it's a rocket!"

[Fiddlers]

And some pics of the boiler.

BTW, I should say that this whole lot was a package deal organised through Eco Angus.

[RichardKB]

Looking good, can't wait for more pictures and info on how it works out.

Rich

[guydewdney]

Surprisingly rusty - considering the consistant good comments that one hears regarding the build quality of akvaterms....

[noelsquibb]

Hey Fiddlers

Looks good so far.

I would have loved to have had space for a 2000 litre akvaterm ( ended up with 1400 litres under the ground )

Those DHW heat exchangers in pic 4,  can you give me approx dims / pipe dia,  so I can work out how much copper smarter folk than me are using ?


Would be good if this thread was posted in the 'show us yours' department

Dorset you say ?  There enough trees there to feed a 25kw super log boiler ?

regards

noel

[knighty]

Those DHW heat exchangers in pic 4,  can you give me approx dims / pipe dia,  so I can work out how much copper smarter folk than me are using ?

I was just thinking they look a bit on the small side for DHW !

(no experience here tho)

I'd have thought you'd want a very large heat exchanger in the bottom to pull out as much low level heat as possible before it goes to the top of the tank


EDIT: actually.... maybe they're bigger than they look in the photo... the mounting plate looks pretty small... but looking at the photos of the holes in the tank they must be pretty big really ?

[Fiddlers]

Hia all, the coils are the smallest that Akvaterm do (LK35), primarily because of budget constraints!
Physically I didn't measure them but I'd guess at about 1m long and 22mm finned copper pipe? they're rated at 90Kw and 35l/min flow rate. In the picture you can just see the edge of a 26" mountain bike wheel, unintentionally there for size comparisons LOL
The installers mentioned that because we'll have a long pull on the DHW they could install a pumped loop that will give us "instant" water at the taps while the pump is running, i.e. have it on a timer. Other times we'll have to be patient. This system will of course be slightly lossy so not ideal. I guess we'll just have to see.

Re rust - yeh this seems to just be a very light surface rust and I'm hoping will completely flush away. I wasn't sure if this is normal or not?

[Brandon]

the rust and the wee puddle would to me at least indicate that it has been filled to be tested

[Moxi]

Wee puddle urgh you'd have thought they'd use water! 

 

[noelsquibb]

Hi Fiddlers

thanks for the approx dims on the DHW exchangers. The pipe in the pic looks smooth so I guess the fins are close enough to blur into continuous, at navvi resolution.

Can you confirm the actual dims of the stored water ?  I'm guessing that its 2m vertically and 1.128m dia.
Just curious regarding the aspect ratio.

What thickness of insulation is there on the bottom of the tank ?

I'm surprised that all 2+ tonnes of weight is loaded onto three legs. Would have thought a flat bottom onto a prepared floor would have been more friendly.


I would be interested in the mix of materials that will be in contact with the stored water.

i.e. -  is the tank skin stainless steel ? coated or not ? grade of steel ?

What is the prong made of, that seems to act as a rigid support for the heat exchanger coils ?

Is the tank going to be sealed and pressurised ?

Is the water in the main body of the tank going to be replenished by a cold feed or will the water remain in the store / log boiler circuit ?

I'm asking because I have inadvertently created a battery with my underground heat store and am having to learn  chemistry.

Hopefully Akvaterm will have learnt these lessons and only incorporate materials that will survive beyond any
warranty period.

And I would appreciate any info that increases my understanding of heatstores.


regards

noel

[Fiddlers]

Hi Noel, I'll answer what I can
The coils are definitely finned, though the fins are only 1-2mm high. The photo I took isn't particularly well focused but below is a slightly better clipped pic showing the fins.
Tank dims are 2.1m high (from floor to top of tank) and 1.4m diameter. there's 100mm or insulation, so make that 1.2m dia.
I'm assuming that the insulation is 100mm all over, there's certainly some squishy stuff on the bottom but it's all covered with protective plastic so difficult to tell.
The 3 legs are _very_ sturdy. I was surprised too but it seems a well proven design. The metalwork is shaped for strength here, it's not just flat.
The prong in the centre of the coil is just steel bar by the looks of things. it's just there to give the copper something sturdy to sit on

My tank is rated at 1.5 bar and my intention is to use it on the existing open vented CH system. I may well have a pumped DHW circuit since there will be a long pull through those 2 coils.

The tank water will be pumped through the boiler circuit as well as through the CH radiator network.

Underground battery sounds like "fun"... how many Watts did it generate?

Cheers,
James

[noelsquibb]

Hi James

Thanks for the closeup pic of the heat exchanger.

now dont you go getting alarmed but the steel bar you so casually dismiss might be all you need to be making your own leccy.

I found a reference on Akvaterms website to  - one magnesium anode is a part of delivery; upon customer‘s request it is possible to install a maintenancefree anode made of titanium -  so you might be interested .

Can you do a pic of this sacrificial anode and tell me how it is connected ?

As you didnt confirm the tank material, I was trying to find out what it might be, sort of assuming its stainless steel but then again, that pic of the inside had me wondering ....   still dont know.

My underground battery is indeed fun and if you really have nothing better to do, you can find out what steel, copper, and water do given the chance -  http://www.navitron.org.uk/forum/index.php/topic,8946.0.html.
Fortunately we have recently welcomed Chemistry teacher, Pontiff,  to the forum and he has been able to explain whats happening with various links and PDF's.

Its not pretty though.

You have a well established manufacturer and supplier, should you ever have any problems with the chemistry and if you run the tank with the lid on and a header tank to maintain some pressure you will probably be ok.

Just look at the connection to the header tank and try to ensure you remove any air in the Akvaterm.

Hey, Im probably over reacting .......... 


noel

[billi]

perhaps i never get that right , but surely that store  seems to me normal steel ,

the thermal store i know is as well  (even much more pricy), but i will not get it into my brain , why all these copper coils ? And why not run all heatsources in the tank direct and drawers (heating) out of it and just have a stainless steel coil runing trough the tank for DHW ?
Hope someone gives me a lesson (again)

Billi

[Fiddlers]

Hi Billi, I think you're right about the tank being made of normal steel. As for heat exchangers, the two coils are only for DHW. One's installed at the bottom to act as a "pre heat" and the 2nd at the top to draw out the heat and they are connected in series, i.e. mains cold feeds input of bottom boil, output of bottom coil to input of top coil, output of top coil to DHW. The idea of the preheat is to try and maximise the use of the cool water at the bottom of the tank, which should still be warmer than the incoming mains cold. This should also help maintain stratification.