How much of a difference does efficiency make?

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ctaco

New Member
Nov 8, 2015
12
NY
I'm a very indecisive person and thought I had narrowed my insert choice from 2 (Lopi or Pacific Energy) to the Pacific Energy Summit model. But then of course I went to another store and saw the Vermont Castings Merrimack insert and I've un-made up my mind.

I think the Merrimack is a much prettier stove and I like that it's cast iron but it's rated at 75% efficient while the Summit insert is rated at 80.4%. Is this something you think I'll see a big difference between? I'm figuring that those ratings are pretty variable but obviously one has the potential to be more efficient. I prefer function over form but if the difference in efficiency is barely going to be noticeable I'd rather buy the more attractive one. However, if I'm going to see a big difference in how much wood I'm going through between the two then I'd suck it up and buy the Pacific Energy insert instead.

I live on LI and will be using this as my main heat source (the house currently has electric heat) this year but next year the home will have geothermal heat and the insert will only be a supplement to that.
 
The Merrimac is a handsome unit. My two concerns with it are a lack of ashlip can mean ashes getting sucked into the blower unless one is sure to turn it off at each loading and ash cleanout. The second is the use of faux brick panels instead of conventional firebrick. You might ask your dealer what the cost of replacement is for these panels. There are several of them and I suspect they will need replacing every 5 yrs or so depending on how gently or roughly logs are loaded into the stove.
 
The Merrimac is a handsome unit. My two concerns with it are a lack of ashlip can mean ashes getting sucked into the blower unless one is sure to turn it off at each loading and ash cleanout. The second is the use of faux brick panels instead of conventional firebrick. You might ask your dealer what the cost of replacement is for these panels. There are several of them and I suspect they will need replacing every 5 yrs or so depending on how gently or roughly logs are loaded into the stove.

I had no idea that they were any different than typical firebricks. Is them breaking an issue people tend to have? Would it be possible in the future to replace them with conventional firebricks or are they sized specifically to each stove? I'll definitely ask more about them. None of the dealers I went to had even mentioned this to me.
 
Efficiency does make a big difference in the long run. Though as you seem to already be thinking, 5% isnt a major difference IMO
 
The Summit is guaranteed (based on many experiences here) to be a great unit. The Vermont Castings company has a shakier history. Some of its products are fine while some are trouble-prone.
 
I haven't read of the refractory panels failing on the newer VC stoves. Mine are original (7th season).
You may want to search this forum for 'Merrimack' directly.

The newer VC non-cat stoves seem to do ok. I have no issue with my Montpelier. BEGREEN has a valid point about the lack of ashlip.

Good luck
 
Welcome to the forum btw...another Long Islander
 
Thanks for the input Fod01. Sounds like the panels will stand up reasonably well given moderate care in loading. It's good to hear that the Montpelier is still keeping you warm and happy.
 
I'm under the impression that manufacturer efficiency ratings are can not be construed as very firm numbers, so I don't think I'd make a decision based solely on a 5 percentage point difference. I'd start by following Fod01's suggestion to search the forum to see if there's any Merrimack users who are disappointed in their insert.

That said, assuming those figures are accurate, the difference in wood consumed for the same amount of heat delivered should be 7.2%.

So per cord burned in the Summit, the Merrimack should take an extra 9.2 cubic feet (split and stacked volume) of wood to deliver the same amount of heat. If you imagine a full cord of 16" splits stacked in a single row that is 4' high and 24' long, you'd need to add another 21 inches to the length of that stack.

Likewise, if you're a full time burner who might consume 5 cords per year in the Summit, the specs suggest you'd consume an extra ~1/3 cord in the Merrimack.
 
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