More Hot Air In Basement?

[SkunkedAgain]

I'm renovating my basement and am getting close to the stage where I can work on the electrical and mechanical stuff. Here is my issue. Like most basements it is pretty cold down there in the winter. It was in the mid-to-upper 50s before I insulated the concrete block walls, now it's 60 degrees. However, I want to blow more heat into the basement.

There is one air vent that comes from the furnace (on the other side of the basement). It's just tin nailed across two joists with an opening in the ceiling to blow in air. There is no return. My questions are:

1) Is it worth adding another run into the vent system? One that maybe went to the far, exterior wall and blew air at ground level?

2) Would I need to add a return if I added another heat run?

3) Do I need to worry about balancing (i.e. should I hire a professional)?

[JohnMickish]

Add baseboard heat and don't worry about it.

[cavalierowner]

First off, how big is the space you're trying to heat? That will help determine how many supply registers and how many return registers you will need. Once you have an adequate number of supplies and returns, installed (with danpers in the duct) you can start balancing by trial and error between your basement and the main floor.

How often will the space be used? If it's used infrequently, electric baseboard may be an alternative if you have enough electric service. But if it's used on a regular basis, then heating the space using the furnace will be much cheaper.

BTW, are you sure that tin nailed across 2 joists is a supply and not a return? That's usually how a return is handled. A supply should be completely ducted all the way to the register.

[LightningBG]

Like Cav stated: How big is the basement? My basement is about 1200 sq ft and the pros put in 6 registers and 3-4 returns.

[SkunkedAgain]

My basement is about 15'x30' on the finished side, and 12'x35' on the unfinished side (separated by a wall and door). Once completed this room will be used most nights. It will be our tv/movie room, has the bar, and all of our musical instruments.

I've though about running baseboard heat. However, I've only got two open circuits remaining on my breaker panel. I need to add a circuit to run the additional lights/power that are currently not adequate in the space. If I were to run baseboard heat, it makes sense to run 220v instead of 110v to make sure that you've got enough heat when needed. So I've got an electrical capacity issue.

The basement heat may be running through a duct now that I think of it. There is no return in the basement but I assume that's because the furnace is in the same room.

[cavalierowner]

For a 15 x 30 room, I'd put in minimum of 3 supply registers, somewhat equally spaced along the outside wall(s), for a reasonably well insulated outside wall. Ideally, the supplies would be low, but that can sometimes be a problem in a basement. I would run a 6" round duct to each register from the trunk line. I would then put in 2 returns, definately low on an interior wall, preferably at the opposite side of the room from your supplies.

My disclaimer is that I have not seen your basement, nor am I a mechanical engineer. What I'm giving you is based on what I typically see in basements, 41 years as an architect, working almost daily with engineers. Good luck with your project!

[muchowja]

Why not add a subpanel and run your entire basement off of it. Since u will need an inspection for running additional lighting and autlets anyway. You just have to know if your service is large enough to add one.

[Tom7227]

A great help is a door. A lot of folks either leave the door open to the basement or don't have one. If you had a door on the bottom end it would help hold the heat down there and keep the cold from dropping in. You can experiment simply by putting up some plastic to see if it's worth the effort.

[hawgchaser]

Lots of good replies here. Oooorrrr...you could just invite my fishing buddies & me over; give us a few bumps and, wallla, lots of hot air. Kidding aside, I think the most economical (long term) is to add an electric heat panel to give you heat as needed. If the furnace/ductwork was properly configured, adding a bunch of supply runs & returns could end up reducing your output in other areas where you actually live 24/7. Just my opinion/experience.

[soldoncass]

There are a lot of things we don't know, about your house, so anything we say will be an educated GUESS. How old is heating system, how old is the house, full basement or bi-level....etc.????? I'm NOT a heating expert, but I can tell you what would be "normal". A forced air furnace with the plenum(hot air side) coming off the TOP of the furnace, and metal ductwork connecting to each hot air register upstairs. Then most rooms upstairs have a return air connecting to the BOTTOM, SIDE of the furnace. These are more often "panned", just like you described what you think is your heat register in the basement. The KEY is seeing where things connect to your furnace.....to the TOP is HEAT....to the bottom / side is return air. A room that size will need more heat and a return(or 2) also if you want to get it comfortable. A few professional estimates would help you figure out what is best for your situation.

[cavalierowner]

That's why I added the disclaimer to my last post! If the furnace is sized correctly, taking the basement into account, then you should have no problem. Normally a heat loss calculation is done that lands somewhere between standard furnace sizes. Standard practice is to round up to the higher standard size. According to my engineers, even if the furnace is SLIGHTLY undersized, that's OK because it will be more efficient, due to running longer with fewer warm-up cycles. I and others can guess all day long, but the only way to know for sure is to have someone do heat loss calculations and compare that to your furnace size.

I don't know about installation cost comparisons, but I do know that operating costs are going to be higher with electric than gas forced air. I base this on how much my electric bill went up when I installed a section of 6' electric baseboard in a room where I had no other options.

[SkunkedAgain]

Thanks everyone. I hadn't considered adding a subpanel but will have to look into that option. Tom's point was also well taken, that there is no barrier (door) to prevent my heat from going upstairs. Due to the layout of the room, a door at the bottom of the stairs takes up a lot of usable space and a door at the top is not possible.

I think that what I've learned here is that if I'm going to go the furnace route, I will definitely be calling in a professional to evaluate and perform the work.

[pureinsanity]

Why not radiant heat? than you do not have to worry about vents or baseboard

[Tom7227]

Pocket Door possible? Before you give up on it try the plastic thing and see what it does for you. It will also help in the summer by stopping the flow of all your AC cooled air dropping down into the basement.

[solbes]

Doors help out a lot. I installed two registers down to the floor on interior walls and one large return just above the foundation block (halfway up the wall). This is for our 14x25 basement Family Room. We keep the house at 67 most of the time and the basement is usually in the 64-65 range which is still comfy with a blanket.

Another option I was going to look at but never did was a duct booster. One of the two registers has a fairly long run and a duct booster would get more heat down there. There were enough controls involved that I would have had to hire a pro for that one.

We also use the gas fireplace w/ blower and thermostat control. Usually I turn on the fireplace once when we head downstairs after dinner. The fire runs for 15-20 minutes or so and then turns itself off when it hits 70 or so. The door at the bottom of the stairs helps keep it warm all night until we head to bed. Cheaper to operate and better to look at than baseboard heat, but much higher install costs. Wish I had gotten one with an auto pilot, as the pilot probably uses as much gas as the 15-20 minutes of "on time" per day.

[LightningBG]

Baseboard heat is expensive to run.

[icefisherman]

I put a gas fireplace in my basement and that made a huge differance. Could you get a gas line brought in somewhere?

[Surface Tension]

Adding heat runs and cold air return is good. Question is how is your furnace keeping on the coldest days? If it is sized right it should be running just about non stop while holding temp . So if you can get more out of the furnace use it to heat the basement.

Being that this is a basement it will be the first room to cool, your going to feel that in between the times the furnace kicks in. Sounds like you have a room down there that isn't going to be heated. That cold air is going to make it into the heated room in the basement as well.

Then lets say your cooking in the kitchen, the furnace is going to kick on less since your heating the main level with the stove or oven. The basement is going to cool and the items in the basement will cool.

For those reasons and since your planning on spending much of the family time down there I'd supplement that heat with another source, just in case. A gas fireplace is an option. Electric is another option. This gives you the option is regulating that heat as you need it. Since your finishing off that space now is the time to for a sub panel. Or depending on what you have, bumping up to 200 amp service.

[SkunkedAgain]

I do have two bad windows down there that need to be replaced. I suppose one of them could serve as the exhaust outlet for a gas or pellet fireplace but since space is limited, I was hoping to avoid adding a fixed appliance. Radiant heat is another option that I haven't looked into all that much although I assumed it would use about as much energy as baseboard heat.

The door has been one of the elusive things for me. There is no straight wall at the top or bottom of the stairs that would hide the pocket door. It's kind of a weird space. I'll have to keep looking at options.

[FishLocker]

A buddy installed electric in floor heat under ceramic tile. Beautiful cozy heat. If it is used every night you can set it on a timer so it is warmed up for the family before House or Fringe comes on the tube =)

They liked it so much he installed the same in the kitchen and bathrooms. His wife loves it in the bathroom with a timer so the floor is warm to her feet when she goes in to shower.

[Hookmaster]

I had the same situation many years ago. In 1995 when we had a new furnace/ac installed the guys put in 3 more heat vents (2 at floor level and 1 in the ceiling) and one large cold air return. It was better but still not warm enough. What I noticed is on cold winter days, the basement would be warmer than usual because the furnace ran more. The only thermostat in the house (a colonial) is on the main floor. So do I add another thermostat and zone heat the basement or replace the wood burning fireplace insert with a gas fireplace. We chose the gas fireplace and haven't looked back.

[Smoker]

We tell all the people we put new furnace in for and the ones who want there basement warmer, run your fan all the time. It will mix the air between main floor and basement and be a more even heat. It won't happen over night but give it a few days and it will stablize.

[pureinsanity]

That option sounds expensive on the electric bill

[cavalierowner]

When I turned our lower level walkout into an apartment for my MIL, I looked at changing the ductwork for the basement and adding zone dampers and another thermostat. I would have had to change almost all the ductwork as near as I could figure, so I brought in a HVAC contractor who looked at it for 45 minutes and came to the same conclusion. Really not feasible in my situation. What I did for winter was throttle down all the dampers on the ducts to the main floor and open all the dampers for the lower level wide open. Then for summer I do just the opposite. It's definately not as good as a zoned system, but it's not too bad. And the price is right!

[pureinsanity]

That is what I did at my old house, but not for the basement, but for the upstairs. Two of the rooms were above a garage and got extremely hot in summer and extremely cold in winter. Summer I would close off the rest of the house except for the upstairs. the cold air would come downstairs and the main and upper levels were pretty comfortable.

in winter I would open them both but close and plastic vents in rooms that were not used, or used very little. I preferably like my rooms colder in winter anyway.