Getting that heat upstairs

[AhhNewEngland]

Hello,

I am an amateur builder and built my own house from a First Day Cottage kit in 2007. It is a post and beam style 1400 sf cape, with an open floor plan on the first floor and 3 bedrooms and a bath on the second floor. Pretty tight and efficient overall. I have a Vermont Castings Resolute Acclaim centrally located on the first floor. Radiant heat is in the basement slab and under the entire first floor, mostly as backup. I also ran radiant under the second floor bathroom, which I keep low so it doesn't run much (I am pretty cheap).

I am trying to get more heat to the upstairs bedrooms. Right now there is a 15-20 degree differential between first and second floor (downstairs was a cozy 73 degrees F last night while upstairs was a chilly 52, outside temps around 17). I have decided to place some registers and am wondering the best location for them and optimal size. There is an open central staircase located behind the stove. The easiest and out of the way place for me to put a register is in the small upstairs hallway, and this would be almost directly in line with the woodstove below. Maybe another in the master bedroom if that would help as well. The master bedroom also has a ceiling fan, which I have tried running and not noticed much difference. It has been suggested my problem is the cold air has nowhere to go, and that seems right. The warm air definitely seems to stop a few steps down form the top of the stairs. I have a small fan mounted there to try and move that air, and it helps, but not a lot.

If I am home all day and feed the stove continually the upstairs will be warm by bedtime(60F on a 10F winter night), but most days the stove doesn’t get started until 4 or 5pm, and that just doesn’t seem to be enough time to get the job done. I have a baby on the way and am worried about keeping it warm, not to mention my long-suffering wife. I don't need it tropical, just comfortable.

I have a nice old 14x12 cast iron register I inherited and would like to use if that size seems appropriate. All ceilings are open so no chance to run ducts. Fire alarms are hardwired throughout the house and a CO detector in the room with the stove. There are no building codes/inspectors in my town but I obviously want to be safe.

I have attached a layout of my second floor, which has changed a bit (for the better) but is essentially the same. The boxed-in stove pipe at the top of the stairs will give you an idea of where the stove is located below (it is actually a bit further back towards the outside wall than shown in the plans). Also included a pic of the stove and the open stairwell behind it.

Thanks in advance. Sorry for the long post but after reading through the forum I recognize that more info is always better than less.

Rich

 

[Adios Pantalones]

I know that your town is lax on inspections/codes, but registers between floors are generally frowned upon for moving woodstove heat because they also could make fire move between floors much more quickly. You can get registers with thermal sensors that melt- shutting them in a fire emergency, specifically for use in this scenario.

Oh- and welcome aboard! Where in NH are ya? I'm in Londonderry. Lots of folks here representin da 603

 

[mywaynow]

Given that the registers will feed cold air down, I would put one in each room at the farthest point from the entry door off the upstairs hallway. Or a position that feeds air closer to the stove without infringing on the incoming hot air. My thought is that the convection created by the air coming up the stairs will drive the coldest air in each room down into the space below and create a mushroom type air movement. The registers should be able to be closed to control flow too. My Cape is heated entirely from a stove in the basement. Only one room is occupied on the second floor, the other shut down. The air cycles up/down through the staircase only. Close temps throughout the house. I burn 24/7 thouigh.

 

[begreen]

Do you have a couple table fans or a box fan? As a temporary test, take one fan, placed on the floor at the top of the stairs and point it downward. Set a second fan, in the hallway that has the cat scratching post, near the base of the stairs. Put #2 fan on the floor, pointing toward the stove. Run both fans on low speed and let us know how it works out for you.

 

[Valhalla]

Heat rises very well by itself, however it needs some help in moving horizontally.

 

[ironpony]

Do you have a couple table fans or a box fan? As a temporary test, take one fan, placed on the floor at the top of the stairs and point it downward. Set a second fan, in the hallway that has the cat scratching post, near the base of the stairs. Put #2 fan on the floor, pointing toward the stove. Run both fans on low speed and let us know how it works out for you.

this should work, i gained 3 degrees upstairs doing something similar
i realize you need about 10 degrees but mine is much more open to start with

 

[AhhNewEngland]

Thanks for all of the quick replies, I knew I came to the right place!
I have set up the fans and will try them for a few days and report back.
I am in Nelson, NH, just a bit north of Keene.
And can someone provide a link to the registers with the sensors so I can check them out?
Thanks again, I'll report back by Wednesday.
rich

 

[NH_Wood]

Do you have a couple table fans or a box fan? As a temporary test, take one fan, placed on the floor at the top of the stairs and point it downward. Set a second fan, in the hallway that has the cat scratching post, near the base of the stairs. Put #2 fan on the floor, pointing toward the stove. Run both fans on low speed and let us know how it works out for you.

+1 on BG's suggestion. Fan placement has made a huge difference on how air moves around my home, and it doesn't take much - small table fans seem to get the job done well. That's quite the difference in temps between upstairs and down. I never seen more than a 10* (or so) difference between up and down, and my setup is worse than yours for moving air upstairs (and I don't even bother with a fan for the upstairs at all). Nelson is a nice town - I head to Keene quite a bit for dinner, etc. - I'm in Rindge, and there taint much here! Cheers!

 

[Adkjake]

Puzzling to me. from your pix and floor plan, doesn't appear that your stove is much further from the staircase than mine is.
The heat just flows up my stairs and the top floor gets very warm. too warm at times, I have to open the sliding glass door on
ocassion.

My house is older though and though well insulated, perhaps there is just enough draw there to pull the heat up

 

[fishingpol]

I know that your town is lax on inspections/codes, but registers between floors are generally frowned upon for moving woodstove heat because they also could make fire move between floors much more quickly. You can get registers with thermal sensors that melt- shutting them in a fire emergency, specifically for use in this scenario.

Oh- and welcome aboard! Where in NH are ya? I'm in Londonderry. Lots of folks here representin da 603

+1. If something goes south, smoke may get drafted away from a smoke detector. HVAC supply companies may sell the fire dampers that go above the ceiling vent. There is a fusible link that melts somewhere near 140 * to 165*, and an accordian-type damper that is spring loaded shuts the vent down once melted. I'd encourage a few extra smoke detectors to CYA. Good luck getting the most out of your set up.

 

[AhhNewEngland]

OK, here are the results of using the two fans as suggested over the last few days:

Day 1
Started fire around 3:30pm, set up fans, everything ready to go by 4.
4pm: 1st floor--65
2nd floor--55
Outside--24
5:30pm: 66
55
18
7pm: 70
55
16
8pm: same as 7pm

Day 2 (today)
Started fire at 8am, burned all day, fans running all day
9am: 1st floor--65
2nd floor--51.5
Outside--15
10:30: 67
18
53
12:30: 71
56
23
3:30: 75 (passive solar helping things along here)
60
23
5pm: 73
60
18

I can achieve 60 to 62 degrees upstairs without any fans if I burn all day like I did today, so I am not sure if the fans were very effective, there still being a consistent 12-15 degree gap between 1st and 2nd floors. But hopefully someone with more knowledge will be able to cipher a meaning out of this info.

Thanks again, look forward to your insights.

rich

 

[DWW68]

I think that you are going to have to crank that stove up a little more in order to get more heat upstairs. I have an 1800 sq ft cape with stove in the basement burning 24/7. My floors are insulated (hydronic radiant heat). Keeping basement door open to allow heat transfer and what rises threw the floor my temp are around 88 in basement, 71 first floor (no help from heater), 65 second floor (with heat running every so often). Crank up the stve and run the fans. See if that works.

 

[begreen]

Curious, where was the upstairs temp taken?

 

[SKIN052]

Do the register thing. I put one at one end of the home near the bedrooms and the other at the opposite end in the kitchen. Big difference. I used only a 4 x 10 register and it worked for me.

 

[fishingpol]

It would seem like an air infiltration issue on the second floor. Do you know if your attic is well insulated? Is there a drop down staircase, scuttle hatch or whole house fan that is not sealed?

 

[AhhNewEngland]

I feel pretty confident that it is not an air infiltration issue, it's a tight house, I built it 3 years ago paying special attention to the building envelope. There is no attic, open ceilings on the second floor (it's not a full 2nd floor, just a 2 foot kneewall). The temp was taken in the master bedroom, which is the one on the left in the plans, about 5.5 feet up at the closet entrance. The 2 red x's in the plans are places where I would like to place a vent, I forgot to mention that before. Does anyone have a feeling if the one in the center would suffice, or if I will need 2, or should I have 2 located in the corners of the house, or should I do 3, one in the center and one in each bedroom along that south wall? Or is the jury still out on vents?
The first floor has been between 73 and 76 for the last 3 hours with the fans going and still no appreciable difference upstairs. I am not sure maintaining an 85 degree 1st floor is the the direction I am looking to go.
Thank you all for chiming in, this community is a great asset to baffled folks like myself.

 

[begreen]

Did you take a reading in the hallway also? That's where I would expect the greatest temp change with the fans. Unfortunately the rooms are isolated from getting direct benefit from this.

I agree with the MBR vent location. The vents should allow cool air to sink out of the rooms and warm air to travel up the stairway to replace it. I'd try the MasterBR and the bath first. I like about a 6x14 floor register for the MBR and a 4x12 for the bath. If that works, the hallway one may be unnecessary.

 

[fishingpol]

When you are upstairs do you feel heat rising up the staircase and cold air spilling down? I just can't understand a +/- 15 degree difference between floors. In my house, it had at one time a gravity-fed coal furnace in the basement probably back in the 1920's. Each room had vents to let the heat up and cold air would spill down the stairs to the large floor grate in the first floor and return cold air to the furnace. I have remodeled and covered the floor vents but still have no problem getting heat to the upstairs rooms. If I sit at the bottom of my stairs putting shoes on by the front door the air exchange is very noticable, almost to a point of a slight breeze coming down the stairs.

Have you tried cracking open a window in each room to see if it will cause a sort of draft to "draw" the heat upstairs into the rooms. I am now thinking the opposite, wondering if the house may be too tight and the air just does not circulate well. Maybe get a few incense sticks and walk around the stairs area and upstairs to get an idea of where the air flows in the house while the stove is running with the windows upstairs closed. After that crack the windows and see if the flow increases or changes. Almost seems like the upstairs is a cold air "plug" that a chimney would experience. Just throwing any ideas out to you that I can think of.

 

[AhhNewEngland]

I will definitely try the incense technique, once I get some incense. I will be interested to get a visual on how the air is moving (or not moving) through the house.
As far as vent locales, the bathroom is out for two reasons, it is tiled and it already has hydronic radiant running underneath with a dropped ceiling below (the only enclosed ceiling in the house). But we keep that radiant very low because the upstairs is cold enough that the zone would run all day unless the door remained shut. Hopefully a few vents will correct that situation. So I am thinking one in the MBR and one in that center hallway, like I have on the plan. Or is there a benefit to having one on the south wall and one on the north?

 

[fishingpol]

You can also use a regular candle and watch the flame direction as it is drawn in the air current. I would try at the ceiling height right as it goes upstairs first.

I would think that if you put a register in the MBR and hallway, you will see an increase in room temp due to air exchanging. Ideally, a register in each upstairs bedroom would help each room. It seems that the greatest concentration of heat from the stove would go up the register nearest to the stove. An infra-red laser thermometer would help you see where the ceilings are warmer in the downstairs areas. What are your stove top temps by the way?