Wiring for Kuuma and LP furnace sharing ductwork

[STIHLY DAN]

ot sure about the normal temp down here, a few degrees above the upstairs temp, due to the Kuuma radiant heat. I'm showing it's 64 at upstairs t-stat, 72

So you have a 2000 sq ft basement basically not insulated with a lot of windows, no heat other than radiant and its WARMER than the living space that is insulated. Something is very wrong here. How many btu's is your lp?

Also adding a return to your Kuuma should help a lot. This will make it a complete system like your lp unit. How the hell is the basement warmer? sorry, stuck on that part.

 

[JRHAWK9]

How the hell is the basement warmer? sorry, stuck on that part.

I could see it if it was a very small insulated area where the furnace was located, but not that huge un-insulated open area he has down there. Almost seems he's not getting good internal air circulation.

What provisions have you made for your cold air return again? Open staircase??

I also seem to remember he has a lot of duct between the Kuuma and where he was tying in.

 

[STIHLY DAN]

Man I wish this was in just one thread instead of 4.

I also seem to remember he has a lot of duct between the Kuuma and where he was tying in

Looked at that again in the ductwork rise thread. I HATE everything about that ductwork. So much air restriction, bends, turns. tee's, then no duct sealer either. What size is the duct when it ties into the lp furnace ductwork @motoguy? There is definitely an issue with the ductwork, that is absolutely the whole problem. Its physics, you cannot have an insulated space getting heat be colder than a non heated non insulated space. You are losing a ton of heat to the basement.

1. We need to look at that ductwork more closely.
2. all joints and connections need to be sealed.
3. return ductwork MUST be installed.
4. duct insulation may be good, It is absolutely needed on your lp, with cooling coil. I can't believe they installed that with no insulation! unless I am assuming wrong and its lined.
5. is it possible to turn the vp100 180*?

 

[motoguy]

Man I wish this was in just one thread instead of 4.

Looked at that again in the ductwork rise thread. I HATE everything about that ductwork. So much air restriction, bends, turns. tee's, then no duct sealer either. What size is the duct when it ties into the lp furnace ductwork @motoguy? There is definitely an issue with the ductwork, that is absolutely the whole problem. Its physics, you cannot have an insulated space getting heat be colder than a non heated non insulated space. You are losing a ton of heat to the basement.

1. We need to look at that ductwork more closely.
2. all joints and connections need to be sealed.
3. return ductwork MUST be installed.
4. duct insulation may be good, It is absolutely needed on your lp, with cooling coil. I can't believe they installed that with no insulation! unless I am assuming wrong and its lined.
5. is it possible to turn the vp100 180*?

Somehow missed all these replies. Ductwork where it ties into the trunk line is 18x10.25

1) Ok. What am I looking for?
2) Certainly. I can find many seams/junctions with openings the size of pencil erasers (1/4" x 1/4" or so), where air is bleeding out. This probably also a contributing factor to poor air output on the far side of the house. Sealing these are on my "to do" list.
3) Possibly. I didn't think that was possible (rather, something I was willing to do) before, but looking at it now, there could be a pretty direct path for the return air. I just took a few pictures, and my phone died...so those pictures will have to wait until later.
4) This may be my fault. The installer asked if I wanted insulation, and being of the "only metal ducting for wood" mindset, I told them no.
5) Possibly. What would be the benefit? It's installed this way because I'll be removing one of the exterior windows, building a wall for the furnace room, and adding an exterior door. Then I can carry wood in without venturing through the living space, and have plenty of room to load. Rotating the unit would require walking between the wall and the unit to load it. In addition, my water cooling coils currently exit on the wall-side. I planned on putting a tempering tank (or two) between the Kuuma and the interior furnace room door (that freshly knocked-out doorway, where the Kuuma supply duct runs), against the foundation wall. Reversing the water coil lines shouldn't be a huge deal, though.

I'm certainly open to ideas on ways to improve the situation.

 

[STIHLY DAN]

Any luck with this.

 

[motoguy]

It's performance is acceptable for now (given the time involved in making changes, vs stuff to do for work). With the firebox temp set on high, it'll keep the house warm on it's own (LP tstat set at 66, with 68-70 being our desired range) through the high teens (outdoor temps). The LP furnace kicks on some if outdoor temps are lower, or if the Kuuma is at the end of a burn.

We started the winter with ~33% LP in the 500 gal tank. I checked it the other day, and we're currently at ~27-28%, so we've used 5-6% of the 500gal LP tank since the initial burn (I'll actually have to check my posts here to know when that was...I'm assuming November). Assuming LP is at $2/gal, that's about $60 worth of propane this winter. My parents have had their 500gal tank filled up 3x this winter...I've seen the truck at my neighbor's house 2x (also 500gal tank).

We've burned right around 2 cord of wood, maybe 3. Each of my rows is just under a cord (roughly 16'x5'x18"), and I started with 8.5 of them. We've burned 3. Between sealing the ductwork and making changes at the Kuuma (fan intake near ceiling, scavenge heat from front door, move low temp sensor to plenum, etc), I think we have a significant amount of performance improvement left. It's just not a priority for this heating season, given it's current performance.

 

[STIHLY DAN]

Glad to hear its getting closer to your needs.

 

[motoguy]

2nd year of usage. No changes to the setup, as last described in this post. I've found the Kuuma to be good for about a 45 degree temp delta with outdoor weather. I still need to do -all- the changes mentioned above, however, we've really grown fond of the furnace (even in this less than optimal performance). My wife has moved from "skeptical about the money we spent" to "it's getting chilly in here. Why don't you fire up the wood stove?" lol

We plan on finishing out the basement this year, so I hope to take that time to implement the changes mentioned above.

Running the furnace flat-out last year, I found I burned 4 (or was it 4.5?) cord of wood. I related this to my dad. He responded that the old Clayton furnace in their previous house would use -teens- of cords of wood each year, and the house would still be cold. He was absolutely dumbfounded that we could heat this house adequately on ~4 cord of wood.

I remember the wood-cutting-marathons we would have, when I was a kid. The idea of cutting a handful of trees a year, in addition to my existing wood, and having a 3-4 year supply makes me ecstatic.