Radiant versus convective heat

[bholler]

I am starting this thread because another thread went completely off track on this subject.

My contention is that while there is an obvious difference between the two in practice most of the time it does not make a huge difference. Id love to hear what other people have to say on the issue

 

[webby3650]

Radiant heat is always better. So are catalytic stoves.

In my home that is pretty well insulated and of modern design I'd guess you'd say I prefer radiant. The stove is centrally located with no real heat sink of any kind. Now I know others with lots of stone around like @Ashful, find the convection stoves to be way more effective. I have one of each I guess. Each work very well, but I do prefer the big radiant heat, but I dislike the temp swings and relatively poor burn times compared to my other stove.

 

[bholler]

Yes I absolutly agree there are going to be examples like ashful where there is clearly a better option. A stove that puts off more convective heat is going to be much better when you have a huge heatsink like he does. But even stoves that have convective jackets still put off a fair ammout of radiant heat from the glass and many from the top.

 

[bholler]

And stoves that are more radiant are still going to make convective heat by the natural air flow over the stove.

 

[kennyp2339]

A mixture of both is best for me, but one has to remember those good old stoves of the 70's (fisher) they were big ole radiant heaters that many current burners grew up with as kids. (I blame fisher for my current addiction today)

 

[webby3650]

Yes I absolutly agree there are going to be examples like ashful where there is clearly a better option. A stove that puts off more convective heat is going to be much better when you have a huge heatsink like he does. But even stoves that have convective jackets still put off a fair ammout of radiant heat from the glass and many from the top.

I agree completely.
I really think some people just want that big heat! You know, like grandpas stove was. If it's not doing that then they think it's not making heat.
My BK is more convective in nature, but it will rock out if needed there's no doubt! It's a good combination of the 2 I think. My Ashford is more of a convection stove, being jacketed on all surfaces. I prefer my princess, being more of a combination of two.

 

[Attaboy]

My first 2 stoves were radiant heat stoves and always found it was brutal heat especially when the fans were off and you were close by, with the fans running for a while and the wood load diminishing it got better. The last 2 including my actual PE Spectrum Classic are convective and these are fantastic as even when close the heat does not batter you with a Louisville Slugger as with a radiating stove.

On the PE I have 2 Camafro Ecofans, whisper quiet and moves lots of hot air, these work extremely well in our opened space home.

Actually thinking of it now the PE Spectrum Classic is both.

 

[jatoxico]

A stove that puts off more convective heat is going to be much better when you have a huge heatsink like he does.

And that was the context it was brought up in the previous thread. Personally most of my experience is with inserts that have had fans so I can only go on reports of others.

 

[Highbeam]

It will never be either or. All stoves make some amount of both radiant and convective heat. Even a hot rock creates a warm air current upwards. Even a fully jacketed wood furnace with huge blowers will emit tons of radiant heat out of the glass door.

If both stoves (radiant and convective) have the same efficiency then the same amount of heat is making it into the room per log. I'm with @bholler in that it doesn't matter much for regular homes.

 

[webby3650]

It will never be either or. All stoves make some amount of both radiant and convective heat. Even a hot rock creates a warm air current upwards. Even a fully jacketed wood furnace with huge blowers will emit tons of radiant heat out of the glass door.

If both stoves (radiant and convective) have the same efficiency then the same amount of heat is making it into the room per log. I'm with @bholler in that it doesn't matter much for regular homes.

It may not matter much in a perfect environment, since all the heat produced is staying put for the most part. But I feel that ones comfort level is different depending on the home and type of stove being used. Of course, one won't freeze to death sitting near a convective stove in a breezy house, but they might not be too warm either.. I know they are both heating, I'm a wood burner through and through, I want to feel that big steel heat after a long cold day on a roof!

 

[brenndatomu]

Even a fully jacketed wood furnace with huge blowers will emit tons of radiant heat out of the glass door.

True words! I have a free standing tin shield that I put up in front of my Drolet Tundra furnace after loading so my tool box that is 4-5' away doesn't end up 150*! A ton of radiant heat coming off the front side of that thing...and exactly why some (Kuuma) won't put glass in their door

 

[bholler]

It may not matter much in a perfect environment, since all the heat produced is staying put for the most part. But I feel that ones comfort level is different depending on the home and type of stove being used

I absolutly agree All I was saying is that in most houses either type will be able to heat just fine if it is sized correctly.

 

[Rearscreen]

Going out on a limb here but I don't believe "a BTU is a BTU". I have gravitated towards a radiant wood stove (PH) and radiant floor hydronic heat kept at 65. (Onyx with Trio Boiler).Here in Vermont on the coldest mornings I can walk around in my skivvies. (Black that image out). The air is not warm, but I am warm. I don't know what is happening BUT when I visit neighbors who have baseboard convection heat, I am COLD. Radiant is more comfortable, that's why we like the suns heat (even though it is bad for some of us - skin wise)

 

[Rearscreen]

My first 2 stoves were radiant heat stoves and always found it was brutal heat especially when the fans were off

That's why I ended up with soapstones after many steel and iron stoves. Soft heat.

 

[rwhite]

I'm a splitter on this. Radiant heat, heats "stuff" the heat transfer to furniture, walls etc allows that heat to be released over time because "stuff" is a better conductor than air. Convective heat just heats air, which is a poor conductor. So the extremes in home heating are forced air vs a wood stove. Both are producing radiant and convective heat just in different ratios. So it depends on what your trying to achieve. If I'm going to work in my garage a few hrs a day I'd much rather have convective just due to the time it takes to warm all the stuff up. In a well insulated house warm air can be trapped and contained for quite a long time but it still cools rather rapidly compared to radiated heat. I prefer radiated heat in the home. So its all to say that both have merits depending on the space your working with.

 

[jeff_t]

I heated with an add on furnace in the basement, until I got tired of setting a 3 am alarm to feed it on cold nights. It was a wood sucking monster. When I put the BK in upstairs, I disconnected the ductwork and burned it when I wanted to do something down there, or to help the stove on super cold, windy days.

Once I got the blowers to kick on, the basement would go from low 50s to sweating in a t-shirt in about thirty minutes. Of course, when the blowers shut off, it cooled just as fast.

I guess my point is, for a shop or other space that isn't heated all the time, heating and moving large volumes of air is a lot more effective than heating stuff.

 

[rwhite]

One other instance where convective wins the day is in large open spaces. It's very easy to move air. Without good conductors it difficult to move radiant heat. Which is why a lot of wood stove guys employ fans.

 

[Woody Stover]

My contention is that while there is an obvious difference between the two in practice most of the time it does not make a huge difference.

I feel that ones comfort level is different depending on the home and type of stove being used. Of course, one won't freeze to death sitting near a convective stove in a breezy house, but they might not be too warm either.. I know they are both heating

Right. This place is leaky, not well-insulated in the walls, with heat-sink plaster-type wall covering. I found the Dutchwest with blower can recover room temp faster. While the radiant Keystone is slower, the radiation gives an extra level of comfort while it's catching up. Most of the time it's a non-issue...the stove gets fed when needed and room temp is 68-71. But in a situation where I was gone from the house longer and room temp would drop off a bit, I would probably want something with a blower for faster recovery when I got home.

 

[Texas123]

I have used both the Wonderluxe Wonderwood and the Jotul 500, and for raw heat output the Wonderluxe is the best hands down. Yes, the Jotul radiates heat in all directions but the Wonderwood heated the airspace better. So, I would prefer a convective design if I had to buy a new stove.

 

[lsucet]

I think that having the flexibility of both, can be a most unless you have a real open floor plan and transoms where heat can keep moving itself creating normal convection. I have to run the fans on mine a few times during the day to not feel the stove room and near rooms to hot plus balance better temp thru the whole house based on my wierd floor plan. sometime the other part is at 70 when the stove area is 78. the part is 70 feels cold when you walk in there and 70 df is a nice temp. with the fans at least for 1/2 hrs on, it is more even and we dont get that feeling that 70 df is cold.

 

[rwhite]

Going out on a limb here but I don't believe "a BTU is a BTU". I have gravitated towards a radiant wood stove (PH) and radiant floor hydronic heat kept at 65. (Onyx with Trio Boiler).Here in Vermont on the coldest mornings I can walk around in my skivvies. (Black that image out). The air is not warm, but I am warm. I don't know what is happening BUT when I visit neighbors who have baseboard convection heat, I am COLD. Radiant is more comfortable, that's why we like the suns heat (even though it is bad for some of us - skin wise)

But a BTU is a BTU. The amount of energy required to raise 1lb of water 1 degree f. With radiant heat (walking around in skivvies) one of the most sensitive parts of your body is in contact with stuff being heated and acts as a conductor. So you feel warm. You can raise air temperature pretty quick but if you walk on a cold floor your gonna feel cold. Take the garage example: I can heat the air and work in short sleeves and shorts in the dead of winter but I'm wearing snow boots because my feet are conducting cold from a concrete floor. Conversely if I tried to heat radiant it might be 2-3 days to get everything warm enough. Not sure what baseboard convective heat is? The best method is what makes you the most comfortable.

 

[Woody Stover]

Not sure what baseboard convective heat is?

Hot water pumped through a copper pipe with fins on it. We had that in our house as kids. It was a tri-level and the lower floor had hot water coils....I loved having toasty feet.

 

[Poindexter]

I am a fan of convection.

Lifetime I have owned and operated several smoke dragons, one EPA non cat and my current BK Ashford 30 with the fan kit.

Of the six sides on the A30, the bottom is pretty well insulated, the hearth directly underneath the stove doesn't get very warm really.

Lots of radiant heat through the glass front; top, sides and back are pretty well taken up with convective air jacket and fan gear, so I'll call it 1:1:4 for insulated:radiant:convective.

House was built ~1980, 2x6 walls, vapor barrier, hats on the breakout boxes, about 40" of blown cellulose in the attic space, triple pane windows, blah, blah, blah. I am running spruce only this year at about 18MBTU per cord. I am "supplementing" my oil fired baseboard heat with the wood stove in about 1200sf typical suburban shoe box.

I keep the stove room at +80dF so the wife doesn't complain so much about wintering in Alaska.

From about 0dF to about +10dF I can leave the convection fans off and get 24 hours burns out of the stove, keeping the stove room at about +80dF all the way through the burn. The back bedrooms, furthest from the stove will be at about +60 to +65dF, so 50:50 shot that the oil furnace will kick in to maintain +62dF. Depends on how tight I packed the stove, how much sap is in the wood, how much wind, that kind of stuff.

Everything else the same in that 0dF to +10dF window I can run the convection fans on high, turn the Tstat up a little bit, run a box fan in the hall blowing cord air along the floor towards the stove, get 12 hour burns and keep the back bedrooms at , well, I am at +75dF now.

Instead of having to feed two stoves for 24 hour burns to keep the back bedrooms warm, I can run one stove plus the fans, fill the one stove twice as often and have as much heat spread inside the envelope as if I was running two stoves with no fans.

I gotta admit, it kinda irks me when I folks post about their burn times being cut more or less in half when they run the fan decks on their BKs and don't go looking to see where their BTUs went. Mine convect down the hall to the back bedrooms. I am glad for that and take advantage of it.

I have fooled with Eco-Fans some. My Eco-Fan does not hold a candle to the deck fans on my BK A30. But when the power goes off we got a shelf of garage sale stuff in the garage and I'll be grabbing the Eco-fan as soon as I find my flashlight. I paid $130 for that thing and no I will not take $5 for it at my garage sale.

On my previous EPA non-cat the eco-fan was brilliant. Just brilliant. I can not see trying to heat an awkward floor plan with wood and no eco fan, I think should be the first add-on when trying to move heat around.

I agree with previous posters, if I was trying to heat a large open shop intermittently a fully radiant EPA non-cat at wide open throttle would be my first choice too, but I would park an Eco-fan on it.

M2c.

 

[rwhite]

Hot water pumped through a copper pipe with fins on it. We had that in our house as kids. It was a tri-level and the lower floor had hot water coils....I loved having toasty feet.

Isn't that radiant?

 

[Woody Stover]

Isn't that radiant?

Yeah, floor is radiant but the baseboard is convecting, air rising through the fins.