Where to start

[jasonh]

Talked to tarm today and the guy I talked to said they are changing a few things on the design for this year and have to meet new testing standards. That's why they are pushing out the "older" model. He also said the optimal storage would be 400 gallons.

For me we concluded that it would be ok for heating but not dhw and heating. Which is what I want to accomplish.

But at $3500, someone with a smaller house or small heat load that's a good deal.

 

[jasonh]

Thinking more about that little tarm, what does the forum think about hooking it up to 1000 gallons of storage and loading it a couple times to get the tank up to temp?

I'm thinking if I can go 12 hours or so on the tanks and get home about 630 pm start a fire, say it burns for 3-4 hrs, then load it up again around 930-10 and let it burn out. In the morning check the tanks and maybe fire it again if needed. That's being on the coldest days.

 

[maple1]

I don't think I can say much more about how I use mine, on top of what I wrote back on page 1.

(Can't believe I wrote that much - holy).

I am about as sure as I could be that you could make that boiler work. Between the time my fire is out at night to when I light it again the next day is about 18 hours. That's doing one burn with 1-2 reloads. You could do that, or a burn in morning plus a burn at night. Storage = flexibility.

Re. the comment right above about the extra DHW load being the deal breaker - I don't think I agree with that. Unless you use a LOT of hot water, DHW is a small fraction of your heating load. I can heat my DHW with electric resistance heating for $20-25 per month. I am quite sure it would cost me at least that much per day if I wanted to heat my house with electric resistance heat to as warm as I am heating now.

It is your money & decision though.

 

[jasonh]

Maple, I just keep thinking of the price for a new unit. I know there is other costs associated with hooking up a system but I can't see how a smaller boiler wouldn't work with alot of storage. To me it would just take more time than a 200k boiler. I was just thinking what you wrote at the bottom of paragraph 2. I could light it before work and then light it after work sometime. Hopefully around dinner time.

We just had an issue with our wood stove this weekend so it's going and some sort of boiler system will be getting installed at some point. No more fires in the house for me.

 

[maple1]

There is another factor to consider that I didn't think to mention before. If your tanks & boiler will all be in an outbuilding, there will be some heat loss. Not actually all a loss, if it's in a building that you can use the heat in. But it all won't get to your house. Which might be a tipping point on whether that boiler is 'big enough'.

 

[stee6043]

One comment I'd add to the few posts above is that many (most?) of us with gassers would not define "lighting it up" as a quick one stop ordeal that involves walking away after 10 minutes and getting a 4 hour burn out of the deal. Generally getting a gasser running "peak output" requires that you establish the coal bed before you toss in a full load. At least this is the way my rig works.

The biggest risk in undersizing a boiler with storage (in my opinion) is that you're potentially going to ride the harry edge of useable heat left in the tanks when the time comes to get another fire going in the evening. If you're comfortable you've got some wiggle room at average loads, than go for it with the smaller boiler. If you think it's going to be tight on an "average" day you might regret going smaller.

The stress-inducer I would have in your case is that there is no downside to oversizing a boiler when thermal storage is involved. The potential downside to going too small could be significant in the grief column. I hate those kinds of decisions!

 

[jasonh]

All true stee. It's just that $3500 is enticing. But I also don't want to do this wrong either just to save some money. As much as a tarm at that cost would be awesome, I don't want to ride the edge of not having enough heat. Maybe if I worked 8 hours instead of 10 it might work better. Plus like I said I have some other plans in mind and the little tarm definitely wouldn't do it.