Bellm Distributing:

Thank you for your interest in our radiant floor heating systems. My name is Duane L. Bellm, and I would like to start this letter by giving you a little background on myself. After high school I attended Ranken Trade School, and trained in auto mechanics, I learned that I didn’t want to be bent over a fender the rest of my life. This training wasn’t wasted, as it gave me a good back ground in the mechanics of how things work. Even your car uses hot water heating principles to cool the engine and to heat the interior. I have been self employed all my adult working life, 1970 to 1980 I operated a farm supply business, and a full service tire shop, and when my partner wanted to retire, I sold that business, and started grain farming with my father-in-law. With the equipment that he had, it only took a couple of months in the spring, and a couple more in the fall. With my personality I was going stir crazy, and became interested in the outside wood burning furnaces. I researched all the brands, and took on a dealership of, in my opinion, the best designed wood furnace on the market. This was the Taylor outside wood burning hot water furnace. I got my first trailer load in the early 80’s, and the business started to grow. By the mid 80’s my sales had increased to the point that Taylor Manufacturing offered me a distributorship that covered Indiana, Illinois, Missouri, Kansas, and Iowa. These furnaces used hot water to transfer the heat into the building, and at that point I had to exchange the heat in some way. At first we used heater cores primarily, placed in the plenums of forced air furnaces, to give forced air heat, but it wasn’t long before I was presented with my first request for radiant heat in the floor of a work shop. I researched every source I could find, there wasn’t much information available in 1986, but I finally got enough information to put in my first system for a customer, with a wood furnace for the heat source. The system worked fine, and the customer loved it, but as time went on I received requests for systems with gas, and electric boilers. Not being familiar with these heat sources, and the challenges of making them efficient, with the floor heating system, I joined the Radiant Panel Heating Association. They offered text books on all aspects of radiant heat. I bought every book I could get my hands on, and computer programs to help design the systems, and to date I have heated homes, warehouses, factories, churches, greenhouses, and shops. My volume on the components that are used to put in these systems, has grown to the point that I have been able to become a factory direct distributor of the line, manifolds, pumps, and heat sources. This allows me to retail all the parts you will need to put in a radiant system, for less than your local heating contractor has to pay for the very same components, and you will also get the experience that goes along with selling more systems in the last year, than your local heating contractor has sold in the last 10 years. Enough of the blowing of my own horn, lets get into radiant heating.

Hot water radiant heat is the most efficient heating system you can install. In the average home, it takes 20-30% less BTU’s per square foot with a radiant floor system than a forced air system with 8’ ceilings, with 14’-16- ceilings, (as in work shops) the savings can be 60-70% or more. Heat loss in any structure is driven by temperature differential. The greater the temperature inside, the faster the heat loss to the cold outside. Forced air systems heat the air to temperatures as high as 120-140 degrees, and on top of this, they locate the registers along the cold outside walls. A perfect way to waste energy, if that is your goal. Add to this, the average forced air furnace has a blower fan of at least 1/3rd hp. That takes 11 amps to start it, and 5 amps to keep it going. Radiant systems on the other hand, heat the entire floor to a temperature of 70-80 degrees, and the heat isn’t concentrated next to the walls, it is even across the entire floor. The average radiant system requires only a 1/25th hp. pump that only needs ½ of an amp to start it running, and 1/3rd of an amp to keep it running.

The average comfort zone setting for forced air heating is in the 72-75 degree range. With forced air systems heated air is expanded and lighter than the air in the room, so when it leaves the ducts, it goes straight to the ceiling. Your thermostat on the wall is located 5’ or more off the floor, so that you can read it. When the heat coming from the ceiling down reaches the 72-75 degree point at the thermostat, the temperature at the floor is 15-20 degrees cooler. Making you set the thermostat at higher temperatures to be comfortable. With radiant floor heat, anything that is in eye sight of the floor is being warmed with radiant heat, yet the temperature at the ceiling is only 2-5 degrees above the temperature of the floor. If you set the thermostat at temperatures above 68-70 degrees you are sweating to death. Every degree that you can lower your thermostat setting and still stay comfortable saves energy costs. With radiant heat, you are using the mass of the floor to yield the heat, so that even after the pump shuts off, the floor is still evenly giving off heat. Unlike forced air heat, that is hot when the furnace is operating and cold as soon as it shuts off. For all the previously mentioned reasons radiant heat keeps paying for itself with savings, at the same time giving you unequaled comfort, this is the best of all worlds.

You can install radiant heat under, in or on top of wood floors, in homes, in concrete floors in basements, or in the concrete floors of commercial shops. All these systems have areas that must have special attention paid to. To avoid problems, and to have the most efficient system possible. Concrete installations is what I will cover here, just because the majority of the systems I sell are put in this way, and that there is no way to cover it all in this short letter.

The reason that concrete works so well as a radiant system, is that it has little or no R value, which means that it absorbs heat rapidly, and just as rapidly gives it up to a colder area in contact with it. The R value of concrete is .1 per inch, so that even if you have a 10” thick wall, the R value of the wall is only 1. Knowing that concrete has such a low R value, and knowing that the average temperature of the ground, even 5’ down is only 45-50 degrees, and knowing that in the winter time the ground gets down to freezing 2’-3’ down, the only way to control heat loss, and heat a building with a concrete floor at a reasonable cost, is to insulate under the whole floor, and up the edges. This is true, no matter what form of heat you plan to use in a concrete floored building. Everyone thinks of heat movement as rising, but the only way this takes place, is by the air in contact with the floor being warmed and expanded and lighter than the air above it so it rises, this is called convection, but the first way that heat will move is by conduction, and conduction will move the heat in any direction, and do it 4-5 times faster than convection. I routinely heat 2000 square foot shops with as little as 18,000 BTU’s, but without an R-10 under the floor and up the edges, that same shop will have an 80,000 BTU downward loss when it is 0 outside, before you put 1 BTU into the building. This building without the floor insulated, would need 120,000 BTU heat source. So I think you can see, the need to insulate the floor is a no brainer.

The next thing I need to stress is the need for steel in a radiant heated concrete slab. There are only two kinds of concrete, concrete that is already cracked, and concrete that if it wasn’t cracked the last time you looked at it, it is now. The Pex tubing that is used in radiant heating, is a very tough material, but when concrete cracks, it leaves a very sharp edge for the line to expand and contract against. You must have enough steel in the floor to keep the crack from parting open, or shifting vertically. When using rebar, I recommend a minimum of grade 60 3/8” rebar on 12” centers, if you want to use the welded 6”x 6”square panels, you want to use no less than ¼” wire, or about 2 ga. The reinforcing steel needs to be placed 1/3rd up from the bottom, of what ever depth of concrete you are going to pour. On a 6” pour, 1/3rd of 6” is 2”, so the reinforcing wire needs to be on 2” stands. The stands need to be close enough together so that when the finisher steps off of the wire it has enough spring to pull itself up through the concrete to where it should be. That means the stands should be no more than 3’ apart on rebar and 2’ apart on the 6 x 6 mats. I must be dumb, because I still can’t figure out how most concrete contractors can defy gravity, and lift the rebar up into the cement while they are standing on it, and how they can keep the heavy steel from sinking right back to the bottom before the cement sets up to hold it.

If you are interested in radiant heating, please give me a call - 217.839.2545