To Insert Or Not...

[Snakebit12]

Thanks to everyone for their advice on my previous inquiry. We have decided to go with either the PE Summit or Enviro Boston...if we go the insert route. Both units are approved for use in ZC factory-built fireplaces.

My final hurdle is safety. The steps in the plan include:

1. A Level II inspection of both the factory-built fireplace and chimney.
2. Reline the factory-built chimney with a 6" insulated stainless liner through the middle of our 11" factory-built chimney - making sure that the chimney cap still allows the factory-built chimney to breathe.
3. Install a block-off plate - It may or may not be necessary with the relining but it is an added level of safety at little added cost.
4. Install the insert per the manual.

The manual installation instructions for the Summit (and literally every other approved insert) states that "the air flow within and around the fireplace must not be altered by the installation of the Insert (i.e. no blockage of louvers or cooling air inlet or outlet ports). This includes the circulating air chambers in a steel fireplace or metal heat circulator."

I have a Heat-n-Glo RHW-51...a large ZC box with dimensions capable of handling almost all approved inserts. I have attached a couple of pictures showing the air vents around the fireplace opening. From speaking with Hearth & Home (parent of Heat-n-Glo), the side vents feed outside air into the fireplace via an OAK. The bottom vents allow room air to be drawn into the cooling chamber of the fireplace.

Heat-n-Glo tech service person says that "An insert will not totally block off all of these holes thus allowing the unit to still breathe"...and further that "(the) unit is a RHW 51 and is a radiant model so (we) can put an insert in without a problem".

All sounds great - I actually seem to have approval from both the insert and ZC manufacturer. But I still have this nagging feeling that the surround will alter the airflow...maybe not block but perhaps restrict?

Am I being paranoid?

Thanks for reading.

 

[Grisu]

It sounds to me like you only need to worry about the bottom air inlets to cool the fireplace; the ones on the side seem to feed the fire, not cool the firebox. If that's the case you will probably be ok at least with the Summit since the blowers and surround will be mounted on the sides while the bottom will be open to the room air. That is actually the place where the Summit will draw in its primary combustion air. Thus those inlets should be able to draw air just fine. May work similar with the Boston but I am not that familiar with it.

Other option include to have the stove stick out a little bit from the firebox. Since the surround is attached to the insert and not the wall you can leave a small gap between the two. That will hardly be visible from the front but people may notice it when looking from the side. Another idea would be to skip the PE surround and have a custom one made that would only cover up the firebox but leave the inlets open.

 

[Snakebit12]

Thanks for the feedback, Grisu.

As I understand it, the blower on the Boston is on the left while the air intake is on the right. If that was the case, it may not be as conducive to my particular predicament.

I need to go see a Summit first-hand.

 

[Grisu]

http://www.pacificenergy.net/dealers/dealer-finder/

Nothing wrong with the Summit. Many happy owners here and the slightly larger firebox may be beneficial given your large house.

Looking at the Boston manual, it has a lower front cover that can be removed. Maybe ask a dealer/the company whether it affects operation to leave it off and take a look whether you would like the look without that cover.

 

[begreen]

I think you'll be fine. The surround is not going to seal tightly against the stone.

 

[bholler]

If you are going to do it first check the owners manual on the fireplace and see if it says you can or cant put insert in it. If you do it leave a gap behind the surround to allow for air circulation. And yes you might be a little paranoid but that is not a bad thing.

 

[Snakebit12]

I think you'll be fine. The surround is not going to seal tightly against the stone.

Thanks - It is great to get feedback on this.

The ZC manual is silent on inserts. The metal tag on the smoke shield says "Do not use a fireplace insert or other products not specified for use with this product." The manufacturer did say that it would work...as long as the ZC can breathe.

The cooling vents are flush with the ZC floor. So the bottom of the installed insert would rest right on top of the vents since the insert protrudes out of the ZC. Air may be able to get around the surround but if the vents are covered by the insert, the ZC can't breathe.

I've thought about putting 2" firebricks on the floor of the ZC and setting the insert on top of the firebricks. This would automatically create a 2" space between the cooling vents and the bottom of the insert.

But then I have to deal with a recessed hearth - 5" or so. That would require fabricating some type of support to fill the 7" gap (with the firebricks) between the bottom of the insert that protrudes out of the ZC and the hearth. I could attach vents on the front of this support that would allow air to flow into the now-unobstructed ZC vents. It wouldn't look very nice, I'm afraid.

At this point, I feel like I am really bastardizing this. Since the Boss doesn't want a free-standing stove, I reluctantly think that I need to walk away from the insert option.

Thanks to all for their input.

 

[Grisu]

I would no tgive up so easily on this. In prinicple you have the ok of the insert manufacturer and the fireplace manufacturer. That is more than most people here can say that successfully put an insert in a ZC fireplace. I would go to a store and check out the stoves. Since the combustion air for the Summit comes in from the bottom I doubt is will sit flush on the hearth where the vents are. At most I would think you would need to raise the insert by half an inch or so to leave enough room for the vents to access the room air. That will be hardly visible.

Have you also thought about the custom surround option? With that you can push the insert further in by just making it as big as to cover the fireplace opening. Or maybe a flush insert? You still have the whole summer to figure something out; take your time and keep asking questions.

 

[Snakebit12]

Thanks Grisu...This has been a bit frustrating.

I neglected to mention that we have decided to explore ripping out the ornamental ZC and replacing with a high-efficiency ZC.

I have read numerous posts on here from posters (who I consider very knowledgeable) who do not believe that you should put an insert into a ZC. Others (who I also consider very knowledgeable) say it's fine. It is fair to say that this is an area of dispute.

I live in rural Virginia and most of the installers here have never installed an insert into a ZC. The CSIA certified installers either refuse to do it or will not guarantee its safety. They advised "removal/re-install" from the get-go.

All of this "lack of certainty" has effectively planted enough of a seed in my brain that I doubt I could fire up an insert without worrying myself to death. I want to enjoy the fireplace (and the savings), not wonder if this is the time when something overheats. We have alot of $$ invested in our retirement home and it's just not worth the risk (however small it actually may be).

Now, on to the forum to find just the perfect ZC fireplace...

And you're right - I have all summer.

 

[Grisu]

I totally understand you and agree that swapping out the fireplace will certainly be the best way to get wood heat and be safe.

To help with the search:

http://www.lennoxhearthproducts.com/products/inserts/wood/ (not all of them are highly efficient, look for the EPA-approved ones)
http://www.fireplacex.com/ProductGuide/FuelTypeOverview.aspx?fueltype=wood&fueltab=0 (The Hybrid-fyre ones are inserts and not for your application)
http://www.icc-rsf.com/en/rsf-woodburning-fireplaces
http://www.napoleonfireplaces.com/products/nz3000-high-country-wood-burning-fireplace/
http://pacificenergy.net/products/wood/fireplaces/fp30-arch/
http://www.kozyheat.com/media/34761/woodburning-usa.pdf

 

[bholler]

I agree totally that that is the best way I am one that thinks that it is generally a bad idea to put an insert in a zc fireplace. It is a very controversial issue here and in the industry as a whole.

 

[begreen]

Doesn't seem too controversial to me, otherwise stove manufacturers would not be approving them for insert installation. csia told me they are avoiding the topic out of litigation concerns. That doesn't make it unsafe or unprudent, just paranoid of lawyers in our litigious society.

 

[Grisu]

I agree totally that that is the best way I am one that thinks that it is generally a bad idea to put an insert in a zc fireplace. It is a very controversial issue here and in the industry as a whole.

It is too small of a market but I would really like to see some tests on that. I have problems believing that a steelbox that was save to run with an open fire in it suddenly becomes unsafe if you put a smaller box in it that has its own airjacket. The top of an insert below the airjacket should not exceed 800 F so that would be the absolute max. the ZC fireplace sees inside. An open fire that does not even reach 800 F?

 

[bholler]

Well the difference is that almost all of the basic or "builders box" zc units say that they are for occasional ornamental fires and are not designed for heating. Which means they are designed and tested to have a fire then go out which does not give allot of time for heat transfer. While the heat from an insert in that box will be less it will be constant and will end up transferring more heat overall. Now As I have said many times before I don't doubt that you could safely install some inserts in some zc units. But by doing so you are voiding the ul listing on that zc unit making it legally unusable. Which opens up lots of liability and insurance issues. I just don't think it is worth the risk. That is my opinion and the view point stated by csia. There are many knowledgeable and respected people who reel otherwise but I will not install one for anyone.

 

[begreen]

Show me a builder's box ZC that has in its manual - do not burn for more than a few hours. How is the UL listing being voided if the the ZC is not modified other than pulling the damper? I emailed csia and got this response:
"There are many liability issues associated with this type of installation that CSIA does not wish to embrace at this time."

 

[BrotherBart]

It just scares me for people to go stuffing four or five hundred pounds of hot stove into a ZC that it wasn't designed to support.

 

[bholler]

by pulling the grate and damper the ul listing is voided

 

[begreen]

by pulling the grate and damper the ul listing is voided

What grate? How is pulling the damper different than running the ZC with the damper open?

BB, if I had heard one report of a floor collapse on a ZC due to an insert I would also be concerned also, but I haven't, nor has Tom Oyen who has been installing inserts for a good long time. Most inserts going into a ZC are smaller and lighter, more like 250-300# I would think. I'll double check.

 

[bholler]

Most builders boxes are tested with a specific grate and it isn't any different than running it with the damper open but modifying it by removing any of the functioning parts voids the listing because that was not the form in which it was tested.

 

[bholler]

This is how I feel as well as many others I also know there are many who feel the same as you. I am not saying you are wrong but I feel professionally it is not worth the risk for me. And I like to let people here know both sides of the argument and to make sure they get it oked with their insurance.

 

[Grisu]

It just scares me for people to go stuffing four or five hundred pounds of hot stove into a ZC that it wasn't designed to support.

That is certainly a valid point.

Most builders boxes are tested with a specific grate and it isn't any different than running it with the damper open but modifying it by removing any of the functioning parts voids the listing because that was not the form in which it was tested.

That is what BG already said: Turn off your brain and just listen to lawyers. I better don't remove anything from my car then because that was not "the form in which it was tested".

 

[bholler]

Well as a pro I need to listen to those lawyers or they could end up taking my house. And if something were to happen and there was an insurance claim due to a fire in a set up like this those lawyers will keep you from getting paid for your house. I don't necessarily agree with it but it is the reality of the situation. Also the ul listing states that the floor must support 100 lbs per sq ft some inserts are absolutely pushing this with out being loaded.

 

[begreen]

bholler we are in agreement for installing safely and for getting the install signed off by insurance.

 

[bholler]

Yes and like I said many times before I believe it can be done safely. I just am not willing to take on that liability and I feel anyone considering it should know both sides of the argument. If they make an educated decision to do it I am ok with that.

 

[BrotherBart]

more like 250-300# I would think. I'll double check.

Like this bad boy?

http://www.americanenergysystems.com/model2insert.cfm

Like I said, they scare me. No history, evidence of anything else to provide. But the reason I wouldn't let the builder put a ZC in my first house. No way to know what is behind, below or above the things.