Is there a Cheaper more basic boiler?

[Brokenstone]

Regarding comparing the slab to water as a thermal reservoir. A slab will lose stored heat much faster. It has much more surface area than a vessel. It is in contact with a colder mass throughout it's greater surface area.
Its not as thermaly dense as water and can store less heat.

A water vessel will store heat longer than a slab will and be able to transfer heat long after a slab is unable to because there is none.

 

[hyfire]

Mbtek makes a non certified boiler, and some people say good things about them for the price, you could buy 3 of them vs a brand name boiler on the market. . I heard customer service is not great, but talked to a few owners, no real complaints just some settings issues. Deliver time is about 2-3 months. Its not a complicated unit and looks simple to clean for the trade off of not being so efficient. 10 year warranty and 5mm thick steel makes them pretty heavy duty.

 

[Eureka]

A slab does not store heat in any way. It distributes and releases it, constantly, and uncontrollably.

 

[hyfire]

Pellets cost more than wood ,unless you got a super deal buying them your going to have no cost savings.

 

[Highbeam]

A slab does not store heat in any way. It distributes and releases it, constantly, and uncontrollably.

I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious that the thermal mass of a slab is not zero.

 

[slowzuki]

Didn't double check the math but a workable 15 C swing in my 32x24ft slab looked to be same energy as a 40 C swing in a 520 gal tank.

Edit, for example, when I brought my boiler online, it took 2 days continuous firing to bring the return water temperature from the slab up to the target temp.

I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious that the thermal mass of a slab is not zero.

 

[slowzuki]

They do store heat, a lot of heat, but yes they release it non-stop at a steady and predictable rate into the space. Predictable enough that you can plan a firing schedule around keeping it a reasonably steady temperature. Again, this is not ideal for a house, works fine in a shop.

A slab does not store heat in any way. It distributes and releases it, constantly, and uncontrollably.

 

[maple1]

I must disagree. As an owner of an insulated 1800 sf slab it absolutely absorbs heat and releases it slowly. There is a huge flywheel effect. Now, is it as good as an insulated 1000 gallon water tank? No. But it is obvious that the thermal mass of a slab is not zero.

Agreed.

 

[hyfire]

Lets not worry about the slab, I would be more worried about finding a boiler. Go to the mbtek site and start talking to some stove users get some info before you buy anything! Newhoirzonstore has a great selection of european boilers. A froling boiler will be 10-14 k. Or check autom boilers in Quebec about 8-9 k for a csa gassifier.

 

[NateB]

After watching the old tarm video makes. E want one of them But I guessing there are few and far between? And I still should have storage Can storage tanks be added on a closed loop glycol filled system?

Consider an Eko with unpresserized storages from Tom in maine. American solartecnics. You can make your DHW, and supplement your heat. Then in the summer you can dehumidify and cool your garage while heating your DHW with a air source heat pump on your storage.

 

[maple1]

Lets not worry about the slab, I would be more worried about finding a boiler. Go to the mbtek site and start talking to some stove users get some info before you buy anything! Newhoirzonstore has a great selection of european boilers. A froling boiler will be 10-14 k. Or check autom boilers in Quebec about 8-9 k for a csa gassifier.

Have more info on the autom thing? Google found nothing.

 

[S.Whiplash]

Pellets cost more than wood ,unless you got a super deal buying them your going to have no cost savings.

That's a bit of a blanket statement, pellets do cost more than wood, but harvesting wood is not free, a significant investment in time and equipment is needed. Directly comparing the cost of wood pellets to fossil fuels per BTU output, they are currently cheaper than oil and propane, but more expensive than N.G.

 

[hyfire]

Have more info on the autom thing? Google found nothing.

Sorry made a typo they are called Autonom!
(broken link removed to https://autonomboilers.com/product-category/boilers/)

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[hyfire]

That's a bit of a blanket statement, pellets do cost more than wood, but harvesting wood is not free, a significant investment in time and equipment is needed. Directly comparing the cost of wood pellets to fossil fuels per BTU output, they are currently cheaper than oil and propane, but more expensive than N.G.

I used to go through 2 bags a day with tax thats $14 worth,. You do a have a point depends what your paying for wood how much is a face cord of wood in equivalent of pellet bags?

 

[Bad LP]

I used to go through 2 bags a day with tax thats $14 worth,. You do a have a point depends what your paying for wood how much is a face cord of wood in equivalent of pellet bags?

Get away from the face cord BS and go to the standard cord of 4x4x8 feet and then run the numbers.

 

[hyfire]

Get away from the face cord BS and go to the standard cord of 4x4x8 feet and then run the numbers.

Comes out to $400 to a cord of wood at 7$ a bag. Wood is around 300 a cord delivered.

 

[Bad LP]

Comes out to $400 to a cord of wood at 7$ a bag. Wood is around 300 a cord delivered.

I was not seeing that 400 last I noticed in Maine but I honestly don’t know today’s numbers. I was seeing 230-250/pallet and that is close to what my wood guy delivered my last order @ 230/cord. He had to raise his numbers because his permit cost from the paper company went up.

 

[slowzuki]

Firewood cost always hard to figure. My free firewood rapidly climbs in cost when contemplating a processor to make it less hassle or better storage to keep it under cover.

 

[Highbeam]

I expect cord wood to be cheaper as a fuel because it’s not a manufactured product. Lots of middle men making profits.

 

[hyfire]

Sorry my number are in Canadian dollars?Does it make more sense now?

 

[S.Whiplash]

I used to go through 2 bags a day with tax thats $14 worth,. You do a have a point depends what your paying for wood how much is a face cord of wood in equivalent of pellet bags?

A ton of wood pellets can be purchased for aprox. $200, that brings down the cost of each 40 lb. bag to around $4.00. A bag of soft-wood pellets contains aprox. 8,000 BTU the equivalent of 2.5 gallons of heating oil or 3.75 gals. of propane. The wood comparison would depend on the species and moisture content but a ton of pellets can be stored in 30% of the space a ton of cordwood can due to higher desnity.

 

[hyfire]

I based my data on 8500 btu per lb of pellets and an average of 20 Million btu for a full cord of wood, which is very conserative. The price in Canada is way more than in the USA for the pellets. I still say if you have the room the normal wood is better since you can burn any wood you can get , which is easier usually than pellets.