Need some advice for my house setup please :)

[Chris K]

I currently have a forced air electric heat system for my home. My house is a relatively new build, built in 2009.

I finished my basement about a year ago, and tied it into the current heat system. There are two rooms in the basement that have are plumbed into the current HVAC System.

I was wondering if I put a pellet stove in my room in the basement, if my current HVAC system would circulate that air through the entire house because I have return vents in both of the downstairs room. The rooms are well insulated on the outside of the studs, and the basement is a poured concrete foundation so it stays about 55-60 year round even in the cold winters.

I was looking at doing it this way potentially because I do not have the money for a boiler to hook into my existing furnace. This is a cheaper option saving me about $2500-$3000.

 

[PELLETCONVERT]

Im in the same boat, i live in a split level home built in 77(fairley open floor plan) which i have insulated well. installed an insert downstairs.
I installed a large oversized return by tapping into the main return duct approx 10 ft out(in front) from the stove (closable for summer)works well for me , 74 downstairs 72 upstairs, took about an hour to regulate once fired up. but i believe a lot depends on your home layout

 

[Madcodger]

Im in the same boat, i live in a split level home built in 77(fairley open floor plan) which i have insulated well. installed an insert downstairs.
I installed a large oversized return by tapping into the main return duct approx 10 ft out(in front) from the stove (closable for summer)works well for me , 74 downstairs 72 upstairs, took about an hour to regulate once fired up. but i believe a lot depends on your home layout

Sounds like a good idea. How large is the return you installed?

 

[PELLETCONVERT]

Sounds like a good idea. How large is the return you installed?

I used this one it is 48 inches , 2 slots rated at 150-360cfm (have a drop ceiling , and this one is more pleasing to the eye

but it was just my choice purely for the aesthetics of the finished room (wife approved) I also added a wall return inside the furthest wall in the room

 

[Madcodger]

Thanks. i'm experimenting with fan cycling to distribute heat as well. Added a 2nd stove in basement office and it makes more heat than I can use in that smaller space. Will need to figure out how to open/close returns when I'm not in office (stove off) though, or might defeat my purpose. It's an automated house so can possibly tie into temp sensor and electric dampers if necessary. Big help knowing size you used.

 

[PELLETCONVERT]

Thanks. i'm experimenting with fan cycling to distribute heat as well. Added a 2nd stove in basement office and it makes more heat than I can use in that smaller space. Will need to figure out how to open/close returns when I'm not in office (stove off) though, or might defeat my purpose. It's an automated house so can possibly tie into temp sensor and electric dampers if necessary. Big help knowing size you used.

your most welcome, like some have said on this forum its almost fun to figure these things out based on layout /design
of your home, nothing is perfect for every situation
someday , ill dive into sensors etc. still have a lot to learn on that front though
best of luck

 

[john193]

Yes you can use your return vents to distribute heat from the pellet stove. This install was suggested to me back in my last house where I had the xxv. You will experience some loss through the duct work but it will work.

 

[Honkerdown]

Have been using the HVAC blower for years to help circulate and even the temperatures out in my ranch with a pellet insert installed at one end of the house. Just recently finished the basement, and installed a USSC 6039 down there, but it too is at one end of the house.

When we installed a new Lennox air source heat pump 4 years ago, the programmable thermostat has a "circulating fan" setting. You can set the percentage of time you want the blower to run to circulate air around the house. I am not absolutely certain, but I think it runs at half speed. When I have one or both of the stoves going, turn that on at about 35%, and it does a nice job of evening things out a bit.

 

[Courtney]

Hi Chris, I have the same config and did the same, pellet stove in basement (santa fe)and heat pump on fan only, for two years. Our winters can get to 0 sometimes so it was a supplement, but not a complete fix. It did help; but I had to almost overheat the basement to get upstairs warm. My answer was to have a second one upstairs.

 

[Madcodger]

Tried running fan with just existing undersized returns in basement today and measured output on 2nd story with thermometer in duct register. Raised temp only ~ 2-3 degrees at best. Always thought more returns needed there, though, and will try to find time to cut them in over next couple of weekends.

 

[BrotherBart]

I have watched people try to make this stuff work for seven years. I have a small fan at the top of the stairs blowing the cold air at floor level down the stairs and one at the entrance to the stove room blowing cold floor level air into the stove room. The cold air being pulled down is replaced with warm air at ceiling level being pulled upstairs.

And right now it is 77 downstairs and 73 upstairs in the 2,500 sq. ft. center hall colonial barn. And 29 degrees outside.

Duct loses kill ya trying to use central HVAC units to spread wood heat.

 

[becasunshine]

Duct loses kill ya trying to use central HVAC units to spread wood heat.

That's been our experience as well, in a much smaller 1410 sq.ft. single story bungalow with a circular floor plan. Our air handler is a down draft: the return is high in the hallway wall, right outside of the room in which the pellet stove resides. The heat puddles up in the ceiling of the "stove room," eventually spills through the doorway of that room and into the adjacent hallway where it no doubt puddles up on the ceiling again, and it is puddling up right next to that HVAC return. Theory has it that the pellet stove heat should get pulled into the return and sent through the ductwork in the attic, pulled by the air handler through the gas furnace, then through the ductwork in the crawl space and out of the floor registers.

We've tried this. The subsequent air coming out of the ducts is cold. The ducts in the attic are swaddled in insulation; they were covered in insulation with a vapor barrier around it when we moved here, and we've put even more insulation over them. The underside of the floor in the crawl space is insulated as well, and those ducts are also enclosed in that insulation envelope.

Pay attention to your air handler and the difference in fan speed between using the furnace and using the air conditioner. The air handler moves a much greater volume of air at a much higher force for the heating side of the equation, pulling it through flames like blow torches in your gas furnace. There is a whole lot of overcompensation going on at the air handler/furnace point in the circuit, with a massive amount of BTU's being produced to heat that air, because of the heat loss in your ductwork. If you switch to the air conditioning side of things, the air handler fan blows at a much reduced feed.

No way any pellet stove standing separately in a room is going to put out enough BTU's, remotely from the duct circuit system, for that heat to survive the circuit through the ducts (most probably in an unheated portion of your structure) and push hot air out of the registers.

We don't live on two stories, but honestly, our experience in our house is that the convection current is best left alone. The more we try to mess with it, the more disrupted it gets and the more BTU's get dissipated in the process. I'm sure it's different for those trying to heat multiple levels.

During extreme cold weather for days on end, when the other end of our small house opposite the end with the stove tries to dive off of the temperature cliff, a box fan in the stove room pointed toward the stove pushes the heat toward the other end of the house a little faster. That's about the only "intervention" that works for us- and even that draws cool air across the floor in our living room (as it should.) We can feel that cool air moving at floor level, it is noticeable, and honestly, unless the other end of the house has fallen off of the temperature cliff we're more comfortable without the fan pulling cold air across the floor.

I like the vents through the floor idea to allow heat to rise- is that possible in your application?

 

[Madcodger]

Excellent observations and summaries. As noted, though, fire codes and vents in floors often don't mix so I think I'm stuck with relying on the stairs and possibly improvements to ducting. I've been intending to call the duct sealing people (from inside out) for two years now as losses in unconditioned spaces are so bad in this house.

 

[becasunshine]

Excellent observations and summaries. As noted, though, fire codes and vents in floors often don't mix so I think I'm stuck with relying on the stairs and possibly improvements to ducting. I've been intending to call the duct sealing people (from inside out) for two years now as losses in unconditioned spaces are so bad in this house.

I came back to follow up and say that if you aren't physically moving your ductwork to accommodate a freestanding pellet stove or if you aren't installing ducting just for the pellet stove, and you've already installed the pellet stove in a location in which you want it anyway, go ahead and try the air handler fan to see if it works for you. There's no cost nor disruption to trying it. Every house is different and every pellet stove install is different. Based on our experience here, I'd not tell anyone to install a pellet stove in a particular location in order to move the heat around via an HVAC return and an HVAC air handler. It didn't work for us.

Our ducts are covered with insulation but I also have to admit, we've not had them specifically checked for re-sealing nor have we had them re-sealed, nor do I know that any previous owner has had them checked either. I'm trying to remember if the HVAC company checked the ducts for leaks when our new central air was installed a few years ago... something is tugging at the corner of my brain that says that the guy who sold us the a/c unit told me that the ducts were fine, but I can't quite recall that conversation. We've done a bit of work to the house in the 7 years that we've owned it, so some of the project details are beginning to run together in my brain. For all I know, the ducts are leaking into all that insulation! I suppose we should have them checked, although the attic and the crawl space haven't been particularly warm or cool while the HVAC is running.

Good call about fire codes and vents through the floor- I hadn't even considered the fire code issue but that makes all kinds of sense. I was in a house fire as a small child and I have all kinds of respect for fire codes. PAY ATTENTION TO THE CODES, PEOPLE.

Drolet makes a large stove, the ECO 65 that can accommodate a plenum kit. The stove is attractive but the plenum kit is rather "heat plant ductwork" in appearance (as opposed to loft/exposed ductwork in appearance) and probably isn't suited for finished living spaces, i.e. my personal preference would not be to have the stove in a finished basement that is used as a den or family room with the plenum kit coming out of the top of it- but that's just me. It may not bother others whose needs are different.

 

[Madcodger]

Called the air sealing people today but have not spoken with a tech yet. I read about this internal sealing process being tested by the Department of Energy and it got good results so will see what happens (may be a couple of weeks until they test it, and that may not occur if I need to agree to the sealing before testing is done - we'll see). Expecting it to be about $1500- $2000 but given the need for AC in the summer it will likely pay back, especially if I can work with them to put in an additional return in the ceiling near the basement stove. Walked around testing register temps with an infrared thermometer this morning and one whole side of the house is 8 degrees colder than the other! And because I'm using a heat pump, we're only starting with 90 - 95 degree air. It was as cold as 64 in some vents, so that's not helping at all. Definitely a leak in a major trunk area, I fear. Will keep everyone posted on any progress. Until then I just leave the door at the top of the basement stairs open and that helps considerably.