What Gas Insert Brand ??

Efficiency is a delicate subject, because of the differences between what is advertised and what is actually achieved.

In my opinion, the Energuide ratings are the toughest and most accurate for a cold climate:
http://www.oee.nrcan.gc.ca/energuide/home.cfm

Right now that site search is not working for me........whereas before it used to.....

Oh well, another measure is to look for an insert with an AFUE rating. An AFUE of about 74% or higher is good.....the higher, the better in terms of the amount of heat you will get back into the house.

A unit with a fan will tend to get the heat out better and quicker.

Depending on the insulation level of your home, a unit with an input of 28,000 to 35,000 should do the job. Keep in mind that a gas insert is not for 100% heating the house - it is a supplement and backup to your existing system. If you get a unit which is too big, you might have to turn it off when the house becomes overheated in mild weather.

petiboy,

How big is your masonry fireplace (height, width, depth)? That could end up being the biggest limitation in your search.

Also, I think this is the site Craig was referring to.

http://www.oee.nrcan.gc.ca/equipment/english/fireplace-search.cfm?PrintView=N&Text=N

As I've said before, the CSA rating/testing isn't perfect either and if the unit you are interested in isn't sold in Canada, then it won't show up here. Good thing about it is that the test is witnessed by an independent test lab. Each unit is tested at the minimum venting allowed (least efficient) and without the blower operating. So it's not real accurate IMO unless you want to see how efficient your appliance is with the blower off.

petiboy said:

I went on the site you indicated and some of the stoves don't exist when you go to the mfg. website (like the jotul GI425DV), are these Canadian ratings the most accurate way to look for efficiency or should I just go by the AFUE rating on the stove literature itself.
Example, if I go to gas fireplaces ratings, hit natural gas, then direct vent and then Insert and look at the Empire dv35in33ln this modal does not exist.

Thanks again,

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Are you saying you looked up the Jotul GI425DV on the Canadian site, but couldn't find it on the Jotul site? If so, I'd say its likely Jotul no longer manufactures it. If you saw it on the Jotul site, but not the Canadian efficiency site, then like I said in my previous post, only stoves sold in Canada go through CSA efficiency testing. Otherwise its a waste of a few grand for the mfg to perform it.

http://www.heatnglo.com/products/inserts/gasInsertDetail.asp?f=07900

FB-IN is AFUE rated 77% efficient

We install a lot of them and don't have any problems.

Not to sidetrack the discussion, but has anyone found a stove/insert that is over 80 or 90% efficient? I realize zone heating has its advantages, but my gas furnace is 91% efficient.

Chris

jtp10181 said:

http://www.heatnglo.com/products/inserts/gasInsertDetail.asp?f=07900

FB-IN is AFUE rated 77% efficient

We install a lot of them and don't have any problems.

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Hmm 77% AFUE for an insert?? LMFAO!! Not sure where you or your mfg got those numbers, but CSA lists that same insert as at most 46% efficient, 43% on NG. Meaning for every dollar you spend on LP, $0.54 goes up the flue. Granted with most mfg's the AFUE/SS efficiency numbers are at least in the ball park with CSA, the ones you quote are almost exactly the opposite. I'd suggest you contact your rep and ask WTF! because someone has told you a less than truth that is being passed on to your consumers.

Manufacturer HEARTH AND HOME TECHNOLOGIES
Brand Name Heat-N-Glo
Model Number FB-IN
Fuel Natural gas/propane


Max Input Rating 38 000(NG) 36 000(LP)
Min Input Rating 27 000 22 000
Fireplace Efficiency (FE) 43.6% 46.2%


This is exactly what I'm talking about people, different test methods some witness by an independent lab, others by salesmen and a drunken sailor. Some real world, others are marketing.

Redox said:

Not to sidetrack the discussion, but has anyone found a stove/insert that is over 80 or 90% efficient? I realize zone heating has its advantages, but my gas furnace is 91% efficient.

Chris

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That's a great point. The research I've seen shows for the most part people aren't very concerned about the efficiency of their gas fireplace because for the most part if you have a gas fireplace you already have a high efficiency gas furnace which has a much higher efficiency than your fireplace ever will. There are the few in the market out there who have gas become available in their neighborhood, or buy a propane tank and want a fireplace to keep the use of their electric heaters down, but for the most part I've seen a shift away from efficiency as more and more people want the ambiance of the flames without the heat. That way they can burn the fire when company comes over and, or for long periods of time.

At HPBA this year there was a mfg who actually had a ducting kit that sucked heat off the fireplace and dumped it outside. Granted it was a really big fireplace, but none the less it's interesting to see kits like that being developed during this "Green" movement.

The "real" numbers for gas inserts may prove one of my long held theories......that wood, coal and pellet inserts suffer from many of the same problems and yet are often falsely advertised.

While I agree with R&D;that efficiency is not big for everyone.....in the colder climes with heavy users it may be - and especially with solid fuels! After all, how many people would spend 4K for a pellet insert and liner if the resulting efficiency in the room was 45%? (maybe a lot of people would?)......

Reality is always tough.

FYI, a grass roots effort to educate the public (yeah, it needs some work!) is at:
http://www.heatgreen.org/ratings.cfm

I joined just to support them.......at least for starters.

Sumpthin' funky with that link. It looks like there should be links to their awards/ratings, but... nothing. I even tried it with IE just to make sure it's nothing Firefox can't recognize. Stop teasing us, Craig! Who's the winner?

The idea of a modulating pellet burner is particularly intriguing...

Chris

I linked within the site - of you want to get the whole idea, just go toL
http://www.heatgreen.org

Just a grass roots effort to steer those customers interested in efficiency toward the right types of products.

Webmaster said:

The "real" numbers for gas inserts may prove one of my long held theories......that wood, coal and pellet inserts suffer from many of the same problems and yet are often falsely advertised.

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Well let me start this off with a disclaimer, I didn't witness or test said unit, but when I saw 77% efficient I thought that was pretty high for an insert. Free standing stove sure, but not an insert. On the other hand 43 to 46%?? Yeah maybe in a power outage with the blower off. This is part of what I'm trying to get at. The Canadian CSA testing is fundamentally flawed. The test method is set up to show one scenario; minimum flue, blower off least efficient. Their explanation is that it levels the playing field, but how many of you are going to run gas a insert with the blower off if you want to run it efficiently?? On the other hand I think this is a clear example of a mfg who wrote their own numbers for AFUE.

So you are saying the CSA lists it as 46% but then you are saying their testing method is no good? I could take up the question of the 77% efficiency with an engineer if you want, and see what they say.

jtp10181 said:

So you are saying the CSA lists it as 46% but then you are saying their testing method is no good? I could take up the question of the 77% efficiency with an engineer if you want, and see what they say.

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Perhaps you are looking at Maximum Steady State Efficiency? Mine is rated at 85%, Only problem with that stat is that you only get that if you are running it for probably at least 10 hours at a time. Now, I`m not familiar with NG prices, but with our propane that would cost approx. $14 dollars per day of operation at our present cost of about $130 per litre. And this is only for space heating,, what about the rest of the house?

I can only state that we use our`s miserly....

jtp said:

So you are saying the CSA lists it as 46% but then you are saying their testing method is no good? I could take up the question of the 77% efficiency with an engineer if you want, and see what they say.

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jtp, I would be really interested to hear what H&G;'s R&D;says about that big of a discrepancy between AFUE and CSA. The CSA numbers always come out slightly lower in the testing I've done, but never 34% lower than AFUE. I'd email your contact, I think you'll find they'll prefer to call you back rather than write anything down. Again, I haven't tested this unit, it's not one I've been contracted to work on, but in my experience what you're seeing is the difference between results the mfg posted in a brochure they created, and results submitted by the independent (3rd party) test lab to CSA which are then posted on CSA's website. As said the CSA method is flawed too and where I'm going with that is to say that there are things you can do to customize your unit which will affect the numbers, like fire brick, venting and how often you run the blower. AFUE, and CSA don't do an adequate job in those areas, but consumers go home thinking they know exactly how their unit performs.

I don't have the method of test in front of me, but CSA is something like this; you start the unit, clock the BTU's after 15 minutes, and from there on out you monitor flue gas temp and ambient temperature every 15 minutes. Once you get 3 flue gas reading that have a delta no greater than 5 degrees you can call the unit at equilibrium. Once you do that you shut the unit off, and enter a tracer gas which is typically CO into the firebox right above the burner. The tracer gas is one of the bigest differences with the CSA method. You measure the flow rate of the tracer gas while taking a flue gas sample and measure the concentration of CO and the temperature of the flue gas.

By knowing the
1. flue diameter
2. measured flow rate of the tracer gas into the firebox
3. measured concentration of tracer gas in the flue

you can calculate the volumetric flow rate or CFM through the flue.

Then by measuring the
4. ambient (intake) temp
5. exhaust gas temps

you can find how many BTU's you are sending up at flue instead of in your home. You take these readings twice at something like 12 minutes and 17 minutes after turning the unit off.

jtp,

Any word from your engineering contact on those discrepincies in efficiency?

Thanks,

Whops forgot all about this post, I will email someone today if I can remember. Its pretty hectic at work this week.

jtp10181 said:

Its pretty hectic at work this week.

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Wouldn't doubt it, it's going to be a huge year for all of us in the industry!

I just wanted to comment on something that was brought up a bit earlier in this post, about the AFUE of gas inserts vs. conventional gas furnaces. Though the AFUE of a furnace might, in fact, be 91%, I believe studies have shown that most people don't get very close to the stated number in reality. Ducts commonly leak, and commonly run through un-conditioned spaces, and commonly are sized improperly for either the heat load or the blower. Each of these will lower the the AFUE from the "ideal" posted by the manufacturer. So while it's fair to question whether the listed AFUE of an insert is correct, no one should believe they're getting the listed AFUE from their furnace, either.

Well, they shouldn't believe it until it's been proven, I should say. And I'd be amazed if it were true.

dave11 said:

I just wanted to comment on something that was brought up a bit earlier in this post, about the AFUE of gas inserts vs. conventional gas furnaces. Though the AFUE of a furnace might, in fact, be 91%, I believe studies have shown that most people don't get very close to the stated number in reality. Ducts commonly leak, and commonly run through un-conditioned spaces, and commonly are sized improperly for either the heat load or the blower. Each of these will lower the the AFUE from the "ideal" posted by the manufacturer. So while it's fair to question whether the listed AFUE of an insert is correct, no one should believe they're getting the listed AFUE from their furnace, either.

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Can't say I've read the method of test for a gas furnace, but I'm willing to bet it doesn't take much duct work into account. Likely there is a standard minimum run that is tested and the efficiency is based at the furnace discharge rather than inside the home. Makes sense to me since the HVAC work is up to the installer, the quality of their work, and the local climate.

Can anyone elaborate?