new Vapor Fire 100 with very poor heat

[Case1030]

@JRHAWK9 would know better than me...he pushes his VF100 to the max way more often than I do...and has the detailed wood quantity records too...he will be able to give us a definitive answer.
I'm saying 5-6 cords would be max...depending somewhat on wood species...

9 cords at 50%= 4.5 (clayton)
6 cords at 86% = 5.16 (vf100)
Now let's say it only gets 80% now with adjustment 6 cords at 80%= 4.8

Like I stated above, the clayton (long as I have the scenario correct) would probably smolder while no heat is being called. Soon as heat is called the damper opens, not to long after that the plenum probably starts hammering 180-200f air through the ducts. That would explain how the old furnace covered up the issue so well.

 

[gary38532]

Soon as heat is called the damper opens, not to long after that the plenum probably starts hammering 180-200f air through the ducts

Spot on thats how the Clayton ran

 

[gary38532]

I added some crawlspace photos just for fun

 

[maple1]

130 plenum? Is that what I see?

Edit: And no insulation at all in rim joist area? Which is maybe cantilevered with a room above?

 

[gary38532]

130 plenum? Is that what I see?

Edit: And no insulation at all in rim joist area? Which is maybe cantilevered with a room above?

yes all of this is ture

 

[JRHAWK9]

@JRHAWK9 would know better than me...he pushes his VF100 to the max way more often than I do...and has the detailed wood quantity records too...he will be able to give us a definitive answer.
I'm saying 5-6 cords would be max...depending somewhat on wood species...

@brenndatomu and @JRHAWK9 how much wood could a guy comfortably comfortably go through per heating season if he were to load the vf100 full every time the furnace goes down to coals on max setting? I was thinking 5 cords but you two have first hand experience.

What im trying to get at is, if the clayton has an estimated 50% efficiency and burns 9 cords. The vf100 (correct me if I'm wrong) 86%? And on top of that Lampa gave @gary38532 knowledge to bump up the rate of burn capacity. So maybe he is able to go through 6 cords now with the adjustments made? This is all speculation so correct/add on if it's not accurate.

With that logic he should be near the same heat output the old clayton was producing, except at a slow and steady rate of heat delivery.

I push it hard maybe 5-7 days a winter, so I'll look at my records.
Well, if pushing it to the max, which includes loading aggressively on coals......it's possible to burn 175-210lbs of wood a day. So 30 days would be anywhere from 5,250lbs to 6,300 lbs a month. Using what I use for red oak (3,650 lbs/cord), this equals 1.4 cord to 1.7 cord a month of red oak. Over 5 months it's possible one could burn 7 - 8.5 cord if running it balls out 100% of the time.

I have not used 5 cord yet over a ~7 month (early-mid October to early/mid May) "heating" season.

 

[brenndatomu]

I added some crawlspace photos just for fun

You are getting higher plenum temps than I ever have! So IMO, you definitely have high BTU loss...which yes, has pretty much been known for a while now...but without the plenum temp, can't rule out the furnace 100%.
As far as insulating the rim joist/sill plate area as was suggested last night...no reason you can't do that...I have wires stapled to the sill plate just like that...you either work around them, or take them lose, insulate/seal, then staple them back in place...I've done it both ways as needed.
And yes, those bay windows are another notorious loss of heat!

 

[gary38532]

You are getting higher plenum temps than I ever have! So IMO, you definitely have high BTU loss...which yes, has pretty much been known for a while now...but without the plenum temp, can't rule out the furnace 100%.
As far as insulating the rim joist/sill plate area as was suggested last night...no reason you can't do that...I have wires stapled to the sill plate just like that...you either work around them, or take them lose, insulate/seal, then staple them back in place...I've done it both ways as needed.
And yes, those bay windows are another notorious loss of heat!

Ill try to do the best I can to fix it and post updates here as I go!

 

[JRHAWK9]

130° plenum temp......that's even higher than I see with my blower slowed way down. Is that with the blower running?

 

[gary38532]

130° plenum temp......that's even higher than I see with my blower slowed way down. Is that with the blower running?

That's with the fan on low

 

[gary38532]

Would this work? Or should I get something else?

 

[maple1]

I just went painfully looking back again. There was some earlier talk around pages 11 or 12 about duct pressures. Maybe more, I didnt read ahead past that again. There seems by now some obvious air sealing and insulation problems in the duct area. Which should be able to be band aided some. Along with that can you other VF guys review the duct pressure stuff again and see if you think he's ok there too?

I dont think I would rely on those insulation guys you had out if they didnt look at all of your rim joist and basement area, kind of one of the main possible problem areas they should have looked at first and looked at closest.

And, I dont know so that's why I'm asking - how do Clayton fan cfms compare to VF fan cfms? Could be the big difference between the 2 units I dont think I saw mentioned yet.

 

[gary38532]

I dont think I would rely on those insulation guys you had out if they didnt look at all of your rim joist and basement area, kind of one of the main possible problem areas they should have looked at first and looked at closest.

Yeah I agree they didn't give me good advice

 

[gary38532]

I dont know so that's why I'm asking - how do Clayton fan cfms compare to VF fan cfms? Could be the big difference between the 2 units I dont think I saw mentioned yet

I think the fan on the vf100 is a little more powerful but I'm not sure

 

[maple1]

That's with the fan on low

I would check plenum temps vs register output temps, at all available speeds under constant burn condition. Think the data has been kind of scattered even after all the pages. It will take a while, but I would measure plenum temps in the same spot all the time, but also check different registers in varying places at all speeds. You should be able to tell which duct runs are losing the most heat. Would also be interesting to see IR pics of the duct work, say in the spaces and also looking down thru floors and up thru ceilings. For fun if nothing else?

 

[JRHAWK9]

That's with the fan on low

It's also in front were it's normally the warmest and where you stuck the probe there could be some dead air. A more accurate measurement would be up on top of the plenum about center of the furnace body. Not saying you have to do that, but where you took the measurement explains the high reading.

 

[JRHAWK9]

I would check plenum temps vs register output temps, at all available speeds under constant burn condition. Think the data has been kind of scattered even after all the pages. It will take a while, but I would measure plenum temps in the same spot all the time, but also check different registers in varying places at all speeds. You should be able to tell which duct runs are losing the most heat. Would also be interesting to see IR pics of the duct work, say in the spaces and also looking down thru floors and up thru ceilings. For fun if nothing else?

I agree, but I would want to get a good accurate plenum temp first.

 

[gary38532]

It's also in front were it's normally the warmest and where you stuck the probe there could be some dead air. A more accurate measurement would be up on top of the plenum about center of the furnace body. Not saying you have to do that, but where you took the measurement explains the high reading.

Ok next time I make a fire Ill measure it up high for the whole burn

 

[laynes69]

You have a couple of options, but either a DIY foam kit, foam board and expanding foam, or have a contractor come out and spray foam the rim joists. I had an estimate for our home and it was 800.00 to go all the way around the home. The thermal cam is perfect for your crawlspace. Any air entering the crawl will make it into the home. You can also foam all cracks then place fiberglass in there. If you have areas that are hard to get to, taking a cheap plastic bag, and placing a batt of fiberglass in the bag and stuff it into the cavity. When the fiberglass expands, the bag stops the air movement. I've used this technique many times and it works.

 

[SpaceBus]

I feel for you. Most of my first floor is bare studs and rockwool R23.

 

[gary38532]

I feel for you. Most of my first floor is bare studs and rockwool R23.

How are you keeping it warm then?

 

[SpaceBus]

How are you keeping it warm then?

With wood stoves and good insulation. The house is so tight I have to open a window to light the cook stove. At 6df and windy the other night it was more effort than normal, but not too bad. I ran both stoves on minimum loaded up with well seasoned sugar maple.

 

[gary38532]

I think I'm going to look into getting the basement walls foamed...

 

[SpaceBus]

I think I'm going to look into getting the basement walls foamed...

Especially if that's where the stove is.

 

[gary38532]

Especially if that's where the stove is.

Yeah I think it looks like the biggest leak in the IR pictures