Dear Tom: Congratulations on your new column in the BDN. I look forward to following it.

Back during the oil crisis of the ’70s, your partner professor [Dick] Hill developed a high-efficiency wood boiler at the university. It was manufactured by at least three firms (one was the Madawaska, another DuMont). It burned wood in a vertical chamber at high temperatures, stored heated water in a large insulated tank, and used the water to supply baseboards in the living area. A fellow named Bob Cummings even wrote a book about it called “Housewarming,” I believe.

It would seem timely to learn whether any of these units are still in operation; what upgrades might be indicated based on field experience; such as wood pellets for fuel; perhaps with an eye toward reintroducing this quality product to the marketplace. – Bob Haskell, Deer Isle

Dear Bob: Yes, I am very familiar with all three units – the third was the Kerr Jetstream.

They are all still usable and there are some later generations kicking around now, such as the TARM.

Dick defined all the parameters of efficient, clean wood burning; unfortunately, some companies think they should ignore his work!

His simple guidelines would make the marketplace a lot better.

Dear Tom: I am hoping that you can take a few seconds and advise me on pellet furnaces.

My home is big, and was built in the ’60s. This current heating season, I used almost 1,300 gallons of heating oil – my furnace is a Thermo Pride, rated at 175,000 BTU input and 140,000 BTU output.

I am thinking of installing a Harmon PF100 pellet pro furnace in tandem with my Thermo Pride hot-air furnace.

The Harmon is rated at 0-112,000 BTU.

My concern is, do you think this is a good idea? Would this heat the house by itself, or would I need both? Given my oil consumption, how many tons of pellets would it burn? – Ron Sirois, Holden

Dear Ron: The Harmon should be pretty close in taking care of the entire house.

Someone should do a heat load analysis on your home.

Check out http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLoss.htm,

My feeling is that central heating systems that are pellet-based are a year or two away from prime time.

The infrastructure needs to become established for bulk delivery and storage. This is happening but is not quite here yet.

In Europe, there are many standalone pellet boilers and furnaces that function with minimum input from the owner.

I think the current hardware available from American manufacturers require more cleaning and occasional service.

My suggestion is to install a Harmon pellet stove, which will pick up most of your heating needs (depending on how open your house floor plan is) and still have the oil for backup.

The investment is a lot less and you can watch the fire (if you like).

Dear Tom: Read your Saturday column. What do you do when buying a house already built on a slab? How do you determine the amount of insulation? Is there any way to add more? Any way to add radiant heating? Or at least hot water? It presently has hot air, in the ceiling!

I had hoped to build, but haven’t been able to find affordable, buildable land.

Thank you for your help. – Roberta Goodell, Searsmont

Dear Roberta: There are a couple things you can do. To check the insulation on a slab without a frost wall, you can do a small exploratory hole at the edge of the slab and check to see if there is any insulation visible.

The edge should also be insulated and that can be added with some care to not remove soil that is underneath the slab.

The only way to add more insulation is to add it on the inside of the building. You can add insulation on top of the slab, either in between wood sleepers or just cover the entire slab with foam and then cover the foam with tongue and groove plywood or OSB. Foam has a very high compressive strength, but it can work on the edges if you do not use tongue-and-groove covering. The tongue-and-groove subflooring is not necessary if you have the wood sleepers to support the subfloor. This would also allow you to install radiant heating over the insulation.

What is great about this whole concept is that you are now walking on a wood floor with some give to it instead of a hard concrete floor and it is well-insulated.

Questions for Tom Gocze should be sent to homefront

@bangordailynews.net or mailed to The Home Page, Bangor Daily News, P.O. Box 1329, Bangor 04402-1329. A library of his practical home improvement videos, reference material and a home project blog are at bangordaily

news.com/thehomepage.