Trying to improve efficiency

I have a Harman Mark II in my lower level family room and I'm using the stairwell as my duct/return. The stove warms that upper level room well, but the basement is still too hot (600 degree stove temp) and I would like to move more hot air upstairs.

I'm fortunate to have a drop ceiling in the family room and I have an idea. I'd like to pop out a panel and put a ceiling register two feet in front of the Harman and duct it to two wall registers in the upper level.

I think a duct fan is needed. I came across a company named Fantech and they sell some interesting inline duct fans. Their FG6 claims to move moves 303 CFM @ 0 baro. Does anyone have experience with this type of setup or Fantech fans? I wonder if I would need more CFM's to push 18 feet. Is it even worth the investment?

This is a common issue when trying to move heat out of a basement...the first thing I would do is provide an opening for the cold air to return to the basement...ideally at the end of the house opposite the stairwell. You should put the register in a room that doesn't get closed off from the rest of the house, because that would "break the cycle".

i agree with rob find the coldest spot in your upstairs part of the house and put a register there that will allow the cold to drop to the basement to be reheated...anyhow this worked for me

I will also agree do not worry so much about getting heat up, worry about getting cold air down and then no fans are needed , yours stairs will work well for hot air feed but you need something to replace the hot air going up.

Cut your cold air returns in, and run a pipe at least 18" down from the ceiling, personally I would go to within a foot of the ground. This way it assures only cold air comes down and no hot air trys to mess up your return.



Eric


Also why is your stove 600* already, if that is the case you are going to need a bigger stove

Another thought is to have a fan blow down, pressurizing the basement, and then the heat can rise up the stairs. I did that with good success, but the bedrooms at the opposite end of the house where too cold for the women. I had to go back to pumping air from the stove and supplying the bedrooms, I was using a Panasonic FV-40NLF1, but recently installed a more tame FV-20NLF1.

Welcome to the forum Grandpa. The previous posts are very good about sending cold air downstair. You could also check the natural air path in your house. Sometime we think that the air is going about like that or like this but how does it really travel? A good way to SEE the natural air path is to use scent sticks in different places, up, middle, at floor level...in the stairway (upper and at a lower level...). Then try to work as much as possible with it.
If done correctly you can have the same temp. in all the places you want to. Sometime the use of a blower, fan... can be necessary to help the natural air loop.

Photos of my install, stairs to left of the stove, going upstairs, stove installed in basement.

Thank you everyone for your information and replies. Please remember I am a NOOBY with all of this and will take everything into consideration. Allow me to explain further; Our house is a 2900 sq ft above ground that we bought. It's pretty big but there are two basements separated by a SOLID WALL. One basement has a forced hot air oil system and the other basement is the family room with the Harman. Besides the wiring and some plumbing, the only other thing that comes through that wall is a hot air wall register from the oil furnace. That means the Harman is stoking away in a 25x25 room with only a set of stairs to get the heat up.

After reviewing the posts that mentioned a cold air return, I must admit I agree. I went down stairs and put my hand up to that register and was amazed at the amount of cold air being pulled into the family room. However it must be drawing from the furnace/other basement/chimney because my homemade manometer (a Bic lighter) held to the hot air registers throughout the rest of the house show a ZERO draw.

So, my initial thought is to disconnect the duct feeding the family room. I will add more pipe and reroute it to a far point in the house and use it as a cold air return for the Harman. Could I put a Y in that line to install two returns in different rooms? Is that counter-productive?

I think this should be my course of action before adding ducting and a fan to push hot air out of the family room.

How about a schematic showing your duct work, and proposed new duct work? I am having a little trouble following you. That cold air loves to fall before the warm air rises.

2001Sierra,

That fan and ducting is to supply hot air to other rooms?
How far is your longest run of duct?
How did you determine the duct size for the project and the CFM needed to blow the hot air?

Thank you

The hot air is going about 30 feet. The duct size was dictated by the blower. To be quieter the fan supplies a larger duct to quiet the air noise. I now run a FN-20NLF1 at full blast vs. a FN-40NLF1 throttled down with the recomended speed control. Just realize if your vents are on the output side of a blower there is more noise than if they are on the suction side. When I reversed the system the bedrooms where way more quiet, but they also where cooler than the common living areas

Why not a
http://www.amazon.com/LEDwholesalers-GY ... pd_cp_hi_1
if your cheap

Losch Stoker, I saw those Hyroponic inline fans at Home Depot and hey look interesting. I wonder if they hold up since they are so inexpensive. Look like I'll be getting started running some cold returns to the family room next week and see if that pushes more heat up the stairway.

Still have yet to get the return ducts run due to the Thanksgiving holiday and other priorities. However, I have learned to control that beast and get some cooler and longer burns. Here is a question...

I installed another thermo on the stack in addition to the one on the side of the Harman. Keep in mind I never got a manometer to check draft.
I can idle the Harman Mk II at 3/4 turn of the damper and stove temp is 275-300, but the stack temp is 250.
If I run the damper at 1 turn the stove temp ranges 300-375, but the stack temp stays at 250.
At 1 1/4 turns stove temp ranges 375-450, and the stack temp climbs to 275.
At 1 1/2 turns stove temp 475-550 and the stack stays at 275.
If I went 1 3/4 to 2 turns the stove temp get to 600 and can creep over 600. The stack temp stays at 275, but I REALLY DON'T feel comfortable burning that hot.

Based upon stove temp to stack temp, does it seem like I may have a decent setup so far? I have not tested the stove for any period of time burning from cracked open to 1/2 turn on the draft.

I am not sure if this is even comparable to your set up, but with my naturally drafted koker I have yet to have the flue temp (measured inside the stack, above the barometric damper) get higher than 150 or so degrees. Usually my stove front runs about 300 or so, which results in a flue temp of about 120.