What would you do?

Here's my situation. Two family home in Central Maine. Approximately 5,000 sq ft., 2,500 per floor. Two chimney's, one unused the other used by an oil fired tankless boiler located in the full cellar, which is not used for living space. Two single brick unlined chimneys. The chimneys are in the middle of the house and about 20' apart. The unused chimney doesn't have a flue in the basement. The flue opening inside this chimney begins at the first story level of the house. The unused chimney has capacity for one six inch liner but not an eight inch liner when clearance from cumbustibles are taken into consideration. Two zones, two thermostats, baseboard radiant heat. One zone heats up stairs, where people are living and the second zone heats down stairs currently unoccupied but heated to 50 degrees to keep the pipes from freezing. The domestic hot and cold water supply is not seperated, upstair from down stairs. There is no propylene glycol in the radiant system. I believe this is called a two zone, closed, pressurized, hydronic oil-fired system. Correct me if I'm wrong. The house is attached to a two and a half story barn with a dirt floor. The cellar has a dirt floor as well.

My goals is to heat the house independent of fossil fuels with the primary incentive of saving money. One possibility I am considering is to seperate the two floors making them thermally independent with the option of shutting one floor down completely while heating the other with wood, pellets, or other biomas. This would require buying and installing two boilers. I am also considering a water storage tank charged by a high energy short burst boiler. It may be more economical to retain the current plumbing arrangement and install one monster boiler in the barn with an underground hot water transfer storage tank that can hold a charge for 24 hours and requires less attendance. I am open to all suggestions including designer referrals.

What do you recommend?

1. I have not taken electricity into consideration. My electric bills are not what's killing me.
2. I have not done a heat analysis, but I will.
3. I have access to wood.

4. Thank you for the correction: pressurized and closed is redundant. But is open and nonpressurized? Gravity? Please explain this.
5. Two boilers would serve to make each floor independent of the other. The family living upstairs would be responsible for their own heat.
6. One monster boiler would heat the entire house without seperating the floors. I use the word monster to describe a boiler like the Garn or other boilers I have seen that use gassification and solid logs creting an enormous output of heat in a very short time. This would only be efficient with a water storage tank to hold the otherwise dumped energy and use it to heat the house when the boiler is not breing fired.

Bill,

Heating the whole house with wood is primary to having the tenants pay their own way. So, weather I seperate the plumbing or not, My main goal is to heat both parts of the house with wood, even if it means some of the heat would be used to keep the pipes in an empty apartment from freezing. If the plumbing were seperated, I could pump the downstairs with glycol and not worry about the tenants. One day, I hope to have the entire house occupied year round. Right now the tenant is upstairs and I am out of town. So it is my apartment that is unoccupied and heated at fifty degrees to keep the pipes from freezing. When I got into this I had no idea the rent, $300/mo which included heat would pay for less than half the cost to heat the house per month with oil.

I am inclined to go with the wood fired boiler and storage tank in the cellar of the barn and leave seperating the two floors for later, if ever. Wood is plentiful and cheap here, so I'm told though I've never bought any. I had a few dead poplars felled, and split and they are stacked in the barn right now. I think you're right that the barn would be a good place for a boiler and storage tank. The cellar of the barn is accessible to a vehicle for deliveirng the boiler, parts and unsplit logs. Because the floor is dirt, I can dig a hole for a water storage tank.

If I buy two wood pellet boilers from Harmon, put one up stairs for the tenants and one in the cellar for the first floor, I will still have to seperate the plumbing and use electric heat tapes to keep the pipes that pass through the down stairs from freezing up.

I see you have a two hundred gallon storage tank and are upsizing to 1,200. Why is that?

I'm not at the house so can't check out the rating plate. Why would a tech change to a smaller nozzle on the boiler and how would that affect the cost of running the boiler. Likewise, would would be the affect of an oversized nozzle? I will call Evergreen and have a talk with them. There is no way of talking me into sticking with oil. It is prohibitively expensive. Thanks for the advice.

Since November 1st I have purchased 1,045 gal. of number 2 heating oil. I probably have enough oil stored to make it through the end of March. So, I'm guessing I'll average 220 gallons/mo. for the entire seven month heating season, October through the end of April. Add another 300 gallons for the rest of the year and it brings me to about 260 gallons per month per year on average for this year. Keep in mind the first floor of the house was maintained at 50 degrees all winter. If it were occupied and heated at 65 degrees, the amount of oil consumed would have been much greater. The short answer to your question: How many gallons sof oil are you actually using per year? 1,345, this year. Next year when both floors are occupied, probably 1,800 gallons - just a guess. At the current price of oil in my area that translates into $5,960!

Thanks guys. These are impressive calculations. What is the factor for single-pane wooden double-hung windows with aluminum storms outside?/per sq. ft. I'm not sure I understand how I can better calculate heat loss the differential heat loss between the two floors in the house using room height, and width, etc. It seems the other variables are more determinitive. For instance, that one floor is vacant most of the time and heated at 50 degrees or that the tenants crank up the heat to 80 and open the windows to let in fresh air (not that they do).

1,045 gal of oil is equal to ten cords of wood? I figure that's a ball park. I mean if I had a gasifying boiler and buffer storage, i.e. 2,000 gallon water storage tank, do you think I'd need ten cords of wood?

What is a degree day? I mean how do you calulate that. I am in Piscataquis County, Maine.

The house is big but not that big. I mean, it's about 1,500 upstairs and 2,000 feet down for a total of (I'm guessing) 3,500 sq ft. with maybe 8 floot ceilings.

7,200-9,000 heating degree days per year in Piscataquis, Maine. With my oil consumption for this year I'm looking at 126,000 btu/hr, or 25 btu/sqft. Jersey, Bill, can you define what you mean by efficiency when you say "I don't think that storage will increase efficiency by much, if at all."? And "system efficiency", can you define that?

I've under stand combustion efficiency to mean how efficiently did you combust the wood in the first place, i.e., what percentage of the chemical energy that's locked up in that piece of wood was released as heat energy vs went up the chimney uncombusted? That's the combustion efficiency. Transfer efficiency is what percentage of that heat that you produced is then released in to the living space? It seems from what you are telling me, correct me if I have misunderstood, is that storage won't directly improve my combustion efficiency or transfer efficiency but indirectly it could. And that will be because I will be able to have hotter, cleaner burns and store the energy I can't use during the burn time for later, via my storage tank. But it doesn't necessarily mean I'll be burnnig less wood. But of course, importantly I will have less burden of tending the fire. So storage means, cleaner emmissions, better combustion efficiency, good but probably not better transfer efficiencies, but definitely less fire tending burden.

I found a photograph of my cellar and was able to zoom in and crop out the boiler plate. I have put $2,838.00 US into this piggy bank since November 1, 2007 and I'm never going to see that change again. Is there someone who could translate the numbers on the boiler plate? What do they suggest as to the heating needs for the house when I transfer to a wood boiler? Thank you.

I will take your advice Bill and get it done this winter. I am not at the house now but will probably head up there today with my tape measure, ten gallons of glycol and a pipe cutter. Wish me luck. I will stick around till I hear back from someone regading his post. Any advice on pumping propylene, anticrossive glycol into the system and isolating the downstairs fixture branches would be appreciated too.