Might need a furnace

[John Edward Mercier]

A friend of mine thinks that any kind of heat dries the air and that it doesn't make any difference if it's liquid or forced air. I was under the impression forced air dries it out in the furnace and then blows the dry air out into your house. Anyone know? Seems like Porc Central was REALLY dry with forced air and Liberty Compound here in Keene doesn't seem dry at all and it's steam radiators. Maybe we have minor steam leaks and that's acting as a kind of ghetto humidifier. *shrug*

In a way, yes (though radiant heat doesn't directly warm the air). Humidity is measured relatively... so with the same quantity of water vapor in warmer air, the air is 'dryer'.

I think what your furnace guy is proposing is to add a humidifier directly to the furnace. It will then take the warmer air and add water vapor to it to keep the relative humidity in a comfortable range. Along with that the air will be filtered to reduce dust and other allergens.

Did he also suggest using some format of tankless water heater?

[ByronB]

A friend of mine thinks that any kind of heat dries the air and that it doesn't make any difference if it's liquid or forced air. I was under the impression forced air dries it out in the furnace and then blows the dry air out into your house. Anyone know? Seems like Porc Central was REALLY dry with forced air and Liberty Compound here in Keene doesn't seem dry at all and it's steam radiators. Maybe we have minor steam leaks and that's acting as a kind of ghetto humidifier. *shrug*

I think your friend was right, I've heard people say that forced air furnaces "dry out" the air before but I think that is just a pitch boiler installers use to convince people to switch over to a boiler.

Really if you think about it a furnaces or boilers do not add or subtract any humidity from the home (maybe a little up the chimney but boilers do as well) all they do is add heat to the air (unless we are talking about setting up large radiant panels) which drops the relative humidity... so really humidity-wise I would think you would be better off with forced air because at least you can easily add a humidifier (or AC to dehumidify in the summer) whereas if you run into humidity problems with a boiler setup you are screwed (unless of course you rig up your "ghetto humidifier")

[slim]

A humidifier would be a good idea because moist air feels warmer then dry air. If the air is moist and it feels warm then you would not need to use as much fuel to feel warm.

Another thing you might want to think about is do you want central air in the building? If you do then forced air would be the way to go since you would use the ducts for both the warm and cool air.

Hydronic heating does have it's positives like you do not have the sound of the fan kicking on and blowing the dust from the ducts in to the living area. Hydronic heating also lets you keep different areas at different temps with the use of zones. Hydronic is also considered in a lot of peoples eyes as more luxurious.

[slim]

Dale do you know how old the current furnace is and what the efficiency is?

It's puking carbon into the air ducts.

Dale wants to go with an oil boiler... 200% efficient... or better.

Putting carbon in the ducts that sounds like the heat exchanger has a hole in it and can be dangerous since some of the exhaust gases can be getting in to the house.

As for a oil boiler that is 200% efficient I do not think one is out there. The company I work for highest efficiency boiler is 95% but it only uses LP or Natural gas.

[dalebert]

As for a oil boiler that is 200% efficient I do not think one is out there.

I'm pretty sure he is making fun of my finickiness and indecisiveness. 

[jaqeboy]

A friend of mine thinks that any kind of heat dries the air and that it doesn't make any difference if it's liquid or forced air. I was under the impression forced air dries it out in the furnace and then blows the dry air out into your house. Anyone know? Seems like Porc Central was REALLY dry with forced air and Liberty Compound here in Keene doesn't seem dry at all and it's steam radiators. Maybe we have minor steam leaks and that's acting as a kind of ghetto humidifier. *shrug*

I think the ghetto humidifier phenomenon is real re the steam radiators. They have a vent on each one (usually) and you can often hear them psss'ing.

If you look at the Psychrometrics of your air using the sea level psychrometric chart you can see why the cold air, when heated up is "drier" (relative humidity). EG: if a certain volume of air at 70 degrees held a pound of water and then you cooled it, you'd reach a point where the relative humidity was 100% (ie, that's all the water that volume of air can hold in solution at that temperature) and the water would start to precipitate out and condense on nearby cooler surfaces. If you kept cooling it down to like, 20 below zero F (that'll never happen here,eh?), you'd precipitate out more and more water (snow, eh?) until the air was at maybe 100% RH for that temp, or less - you'd have to look at the chart for numbers, but it might only have .05 lb. of water in it at that point. Then if you draw that air into a house and heat it back up (look on chart for .05 lbs of water in that volume for 70 deg. F), you'd be at a really low R.H., say 5% - that's why it feels so dry in winter. There are other effects going on, of course, but this is the predominant one.

BTW: N.H. humidifier: pan of water on the wood stove. Or, if no wood stove, teakettle on the burner. Run until you get condensation on the windows and then throttle back. You'll feel more comfortable and your skin won't itch as much.

You can get an automatic humidifier that goes inline in the ductwork and plumb it up to the water source, if you want it to be out of the living space. Aprilaire makes them - I can purchase them at dealer prices and install for you, or if you're handy and have tools, you can install it, along with the humidistat.

[dalebert]

Yes, yes, I'm familiar with humidifiers like that. My roommate was looking into them before I left Atlanta and we got the whole schpeel from the guy. I'll probably seriously consider that as long as it's not too expensive, just as soon as I find that damned pea that seems to have been lodged underneath my mattress by some mischievous type, probably the Facilitator! 

[jaqeboy]

Yes, yes, I'm familiar with humidifiers like that. My roommate was looking into them before I left Atlanta and we got the whole schpeel from the guy. I'll probably seriously consider that as long as it's not too expensive, just as soon as I find that damned pea that seems to have been lodged underneath my mattress by some mischievous type, probably the Facilitator! 

It does sound like you've got a leaky heat exchanger if you're spewing soot into the ducts (don't know if he was kidding on that one). That leaks combustion gasses, like carbon monoxide into the house, and can make you sick. In some jurisdictions, the heating tech will "condemn" the furnace (if he sees a defective heat exchanger) and un-wire it and tag it "illegal to re-wire, without repair", by local ordinance. The thing might be repairable, though, just to stay cheaper for now than a complete replacement. There's a couple of other things that can be done to make the furnace/duct/air-moving thing more comfortable and quiet. The co-gen unit I mentioned to you off-line uses a warm air technique of always moving the air, but at a lower speed, so you never hear or feel it. That way you don't get the constant changes of temp as the thing heats up and blows a lot of air around for a while, then shuts down 'til it cools down again. See, the air movement figures into the human comfort sensation, too, so if it's changing, you get a changing sensation of comfort.

Was that pea down under all 21 mattresses? 

[dalebert]

That leaks combustion gasses, like carbon monoxide into the house, and can make you sick.

That's why I told you it was beyond hope, even for just this winter. Also, that hybrid you described seems really nice, but unfortunately I'm almost certain natural gas isn't available and they don't have a propane one yet. Cheshire Oil may be wrong, but they said I won't have natural gas where the house is.

Was that pea down under all 21 mattresses? 

I don't know yet. I've only checked the top 16, but I'm gong to find that damned thing and stick it under the Facilitator's mattress! 

[Lloyd Danforth]

I thought it was a 'princess' who found the pea under her mattresses

[slim]

It does sound like you've got a leaky heat exchanger if you're spewing soot into the ducts (don't know if he was kidding on that one). That leaks combustion gasses, like carbon monoxide into the house, and can make you sick. In some jurisdictions, the heating tech will "condemn" the furnace (if he sees a defective heat exchanger) and un-wire it and tag it "illegal to re-wire, without repair", by local ordinance. The thing might be repairable, though, just to stay cheaper for now than a complete replacement. There's a couple of other things that can be done to make the furnace/duct/air-moving thing more comfortable and quiet. The co-gen unit I mentioned to you off-line uses a warm air technique of always moving the air, but at a lower speed, so you never hear or feel it. That way you don't get the constant changes of temp as the thing heats up and blows a lot of air around for a while, then shuts down 'til it cools down again. See, the air movement figures into the human comfort sensation, too, so if it's changing, you get a changing sensation of comfort.

Was that pea down under all 21 mattresses? 

Jaq you are right a heat exchanger that is leaking can be very dangerous. I remember last year a home had a boiler that was installed incorrectly and the entire family was hospitalized for carbon monoxide poisoning if a friend did not go to the house they could have all died.

Most manufactures have a long warranty on heat exchangers but the warranty is prorated from the date of installation. A example would be a 20 year warranty on the exchanger and it fails 10 years in you get 50% off the cost of a exchanger if it fails 15 years in to a 20 year warranty you get 25%. If the furnace is 10 years or older and the exchanger fails the savings from a new high efficiency furnace would make it economical to just replace the furnace.

As for the co-gen unit the company I work for just introduced a co-gen unit to the market in the US. The unit is expensive right now and the payback is long for the unit. I think maybe 5 to 10 years the cost will come down enough to make it worth while to put a unit in to the average home.

PS could you PM me the name of the co-gen unit that you were talking to Dale about.