FAQ

It is true that most homes in North America are heated using forced air furnaces. In Europe, and other parts of the world, where energy is much more expensive, virtually all space heating and domestic hot water heating is done with boilers. Simply put, water is a much more efficient way of heating; greater efficiency means lower energy costs. In addition, increased efficiency means lower carbon dioxide emissions. And if space is a concern, a wall hung boiler is about as space efficient a heating appliance as you can get. A wall hung boiler large enough to heat a home is not much bigger than a kitchen cupboard. There are other advantages to heating with water. If you are using an in-floor system, the comfort level, with the heat below your feet is noticeably better and with in floor or radiator systems, because you do not have the air movement associated with forced air systems, circulating dust is greatly reduced; this is especially important for people who experience dust allergies. You also have the option to couple your boiler with a Vulcano air handler and traditional duct work in your home. You now have the combined benefits of a high efficiency hydronics heating system with the ability to operate a central air conditioning unit. Your home will function and operate just as it does the use of a furnace, but now you will benefit from the savings of only one combustible source to generate your heating and how water demands, not two. One gas line, one vent, one outside termination, and one appliance using fuel and consuming energy, which also allows you to eliminate the need for a hot water tank in your home. Lowering household expenses and saving you money. The benefits are endless.

The simple answer is yes. In cases like this, the boiler, which can produce heat both for space heating and domestic hot water, is coupled with a device called an air handler for space heating. Hot water flows through the air handler and air passes over the heated coils, much like the way a car radiator works; the hot air circulates through your existing ducting. On the domestic hot water side, the boiler replaces your hot water tank, meaning that you only heat water when you need to use it. This system will significantly reduce your energy consumption and costs for heating and hot water.

There are actually a few reasons to consider changing out an old boiler, assuming you mean your boiler is older than 20 or 25 years. Firstly, the technology has advanced a long way in the past couple of decades, so a new boiler will use a lot less energy than your current old one (see the question about condensing and non-condensing boilers below). Second, parts may not be available for your old boiler, should you have a problem. If this happens in the middle of winter, you are going to have to make a very quick decision about replacing a non-functioning boiler. Most boilers get changed before they completely fail for these reasons. Updating to new technology has many benefits.

All boilers under certain conditions will condense. The difference between a condensing and non-condensing boiler is that a condensing boiler is designed to operate and survive long term in a condensing evironment. A non-condensing boiler will not last, because condensate is corrosive. The condition that causes a boiler to condense is reduced flue gas temperature. The point at which condensing will occur, also called the dew point of the products of natural gas (or propane) combustion, is about 130F. Above this temperature, the moisture entrained in flue products as water vapor will remain vaporized. Below this temperature, the water vapor will change phase and condense out of the flue products as liquid. When this phase change occurs, additional energy is released that is beyond the sensible heat of the flue products. In a boiler, this phase change occurs on a heating surface and the released energy transfers through the heating surface into the boiler water on the other side. By capturing this energy, which is lost out the exhaust stack on a conventional system, a condensing boiler gains efficiency, thus making it much more efficient. Naturally, the products of combustion cannot be reduced in temperature to 130F unless some of the heating surfaces in the boiler are also less than or equal to 130F. The only way to accomplish this is to have an entering boiler water temperature of less than or equal to 130F. Simply stated, if return water to the boiler is higher than 130F, condensing cannot occur; even if the boiler modulates and is at its lowest firing rate. This is determined by the laws of physics. The highest achievable efficiency that can occur without condensation forming inside the boiler is approximatley 87%. The highest efficiency numbers occur when cooler water return temperatures are combined with the ability of the boiler to reduce its firing rate by modulating or staging. Under optimum conditions, reduced firing rate efficiency of condensing boilers can exceed 95%.

AFUE stands for the “Annual Fuel Utilization Efficiency. AFUE is an energy efficiency value determined through a simulation test that represents the operating efficiency of an average installation over the course of a heating season. While AFUE provides a true indication of operating fuel costs, thermal efficiency represents steady state efficiency. Steady state efficiency does not consider efficiencies throughout the input range and typical on/off cycles the boiler is expected to operate. ENERGY STAR® provides AFUE values for products that have an ENERGY STAR® http://www.energystar.org designation and the American Heating and Refrigeration Institute – AHRI www.ahrinet.org provides AFUE values for products listed with that organization.

Your boiler needs to produce enough heat to compensate for the building’s loss of heat on the coldest day of the year. Heating professionals have sophisticated computer programs that can calculate the right size boiler you need. These are called heat load calculations and, among other things, take into account the size of the building, its age, amount of insulation, type and number of windows, building openings, and the climate in your area. The contractor will then select a Radiant boiler that operates within the maximum heat loss of the building. Since Radiant boilers modulate, the Radiant boiler selected will operate at the heat output that matches the heat loss of the building on the coldest day, or on milder days at optimal efficiency at all times thanks in part to a 9:1 or 10:1 modulation rate depending on the model you choose.

Most of the time when your boiler is operating, it will not be the coldest day of the year. In these cases, you do not want your boiler to operate at its maximum output as it will then cycle on and off more frequently than necessary. This will result in it operating at less than its best efficiency, using more fuel and greater wear and tear on the appliance, much like a car driving in stop-and-go traffic, compared to on the highway. Radiant boilers are designed to ‘modulate’, that is match their heat output with the heat required by the building. In this way they operate at the highest possible efficiency, for the conditions, all of the time.

Your Radiant product comes with a 10 year warranty on the heat exchanger, and a two year warranty on all components. Please refer to your owners manual for the exact terms and conditions.