To boiler stove or not?

sas

Hi,

Really appreciate any thoughts on this.

I've a passive house.

I have the following setup:

1. Large buffer tank
2. Solar panels feeding that tank.
3. Oil boiler that feeds buffer tank
4. UFH circuit downstairs for backup heat distribution
5. Towel rads in upstairs fed from buffer tank or directly from oil
6. Provision for a stove

One of the big problems for us when we chose to go passive was that we'd lose our open fire. Our winters are spent watching movies with the fire on.
So when we built we included provision for a stove. We've actually allowed for a pressurised stove i.e. cold water feed directly off mains, 2 inch connections into sewer etc.

The question is whether to go for a boiler stove or a non boiler stove. Price is my issue here. In terms of boiler stoves I have found one for €3600 but that doesn't appear to include the pump set etc. which could easily push that on towards €4000. This also appears to be on the cheap side for room sealed boiler stoves. By comparison a dry stove can be bought from €1690 to approx €2500.

My dilemma is whether the approx €2000 in the difference is a good investment given that I already have oil in place as a backup for the solar. Solar on days like today isn't giving me much at all because my tank never drops below 30. The oill will need to be turned on later to bring it to 40 for showers etc.

The oil we've used so far since Oct 1st for backup heating and dhw is less than 50 litres. The oil burner can provide as much dhw as we need for a day in less than 30mins.

I am assuming that with something in the region of a 5kw room heating stove, the heat will spread downstairs and also rise. My point being that the OIL\UFH combo could effectively become redundant for heating. I'm ok with this. If this actually worked out, then the oil would only be used for DHW.

Thoughts/

manufan16

I got an earlier model of this stove from a company in portlaoise for €2400 , It has ext air supply and boiler. I thought the price may interest you. The initial air tightness test did not show any leaks around the stove itself, a few around the flue I need to look at but that's a separate issue. I am still second fixing so cant really comment on the day to day performance but I would have it going a couple of times a week while working in the house and I find it great so far.

http://www.fireplace-onlineshop.com/fireplace-onlineshop-com/eshop/2-1-Back-boilers-build-in/12-3-CHOPOK/5/71-Fireplace-Chopok-TV-600-500

mine is also linked in with oil/solar/ buffer tank but no controls on yet but I can let you know performance in a couple of weeks after controls in place

JuniorB

manufan16 wrote: »

I got an earlier model of this stove from a company in portlaoise for €2400 , It has ext air supply and boiler. I thought the price may interest you. The initial air tightness test did not show any leaks around the stove itself, a few around the flue I need to look at but that's a separate issue. I am still second fixing so cant really comment on the day to day performance but I would have it going a couple of times a week while working in the house and I find it great so far.

http://www.fireplace-onlineshop.com/fireplace-onlineshop-com/eshop/2-1-Back-boilers-build-in/12-3-CHOPOK/5/71-Fireplace-Chopok-TV-600-500

mine is also linked in with oil/solar/ buffer tank but no controls on yet but I can let you know performance in a couple of weeks after controls in place

I have a corner version of the boiler stove linked to above. 600ltr buffer, 80 solar tubes, UFH and alurads.
We burn turf only and when we have it on a couple of hours, and a good bit of fuel on, the middle stat (3/4 way up the tank) on the buffer tank can go from 40 to 60/65.
Bottom stat stays at 35 ish.
We're no way near passive - 2.5 air tight, 150 full fill cavity. Going through around 600ltrs of oil and 150 bags of turf.
Main reason we went for back boiler (actually top boiler) is that we like the fire on a good bit and stove on it's own would have the house over heated too quickly. Must admit we didn't see too much of a difference in prices of boiler and non-boiler stove models. Cost €600 for plumber to fit, connect up etc - thought he was robbing me at the time!

sas

JuniorB wrote: »

Must admit we didn't see too much of a difference in prices of boiler and non-boiler stove models. Cost €600 for plumber to fit, connect up etc - thought he was robbing me at the time!

I need a room sealed version because I'm pretty airtight 0.32 ach.

I also need a pressurised one which pretty much rules out any commonly available one.

bertie 56

La Nordica, an Italian brand, is doing one with your specs . Check out the Norma S Idro DSA.
4.6kw for air, 14.9kw for water, room sealed and pressurized system ok.
Check more on Google

Certified

sas wrote: »

My dilemma is whether the approx €2000 in the difference is a good investment given that I already have oil in place as a backup for the solar

It would be quite a while before you would get your €2k back through savings as your heat demand is so low. In this case I personally would leave out the boiler at that price and buy a quality 5kw stove that I & herself really really liked and just enjoy the comfort of the fire.

sas

Certified wrote: »

It would be quite a while before you would get your €2k back through savings as your heat demand is so low. In this case I personally would leave out the boiler at that price and buy a quality 5kw stove that I & herself really really liked and just enjoy the comfort of the fire.

Yeah, I'm somewhat leaning that way.

I will stress that the complete lack of support or knowledge (based on my findings so far) on how to plumb a boiler stove in a pressurised system is also scaring me off. The results of a mistake with this could be disastrous.

esox28

hey Sas,

off the top of my head you could connect the stove to your pressursed system by means of plate heat exchangers still keeping the stove open vented, you would need to have some rads off the open vented side of heat link. I havent heard of the mains connected stove I suppose is based on the principle that in an over heat sinnaro the valves would cool stove to the sewer line.