Several other gas heating options are available in addition to the forced-air systems described in Chapter 3.
Installing a central natural-gas-heating system may not be practical or possible if your house is built on a concrete slab or if you live in a mobile home. Specialized gas heating equipment might be a good alternative. There are many kinds available, and you should consult your gas utility or a heating contractor for a detailed assessment. The following are some of the most common types.
DIRECT-VENT WALL FURNACES
Direct-vent wall furnaces are self-contained, sealed combustion heating appliances that draw in combustion air and discharge combustion products through a vent to the outside. They are permanently attached to the structure of a building, recreational vehicle or mobile home, and are not connected to ductwork. These units circulate heated air by gravity or with the help of a circulating fan. Units with a circulating fan yield higher efficiencies.
Wall furnaces are compact and less expensive than central furnaces. They come in a variety of heating capacities with efficiencies that range from that of a standard-efficiency unit with a pilot light to a high-efficiency unit with an electric ignition and induced draft. The AFUE can range from 70 to 80 percent, although generally, high-efficiency central furnaces are much more efficient.
Room heaters are self-contained, free-standing heating appliances with heat outputs much lower than those of central furnaces. Often, they resemble the new free-standing wood stoves. They are not connected to ductwork, they heat only the space in which they are located, and most rooms require their own units. A vent pipe allows the combustion by-products to escape to the outdoors.
Heat is circulated by natural convection or with a circulating fan. Units are available with AFUE ratings between 60 and 82 percent.
A direct-vent, gas-fired baseboard heater has recently been developed; it resembles electric or new hydronic (hot water) baseboards. It allows the retrofit of existing electrically heated homes, without the need for a chimney or a central distribution system.
NATURAL GAS AND PROPANE FIREPLACES
Gas fireplaces are becoming popular, both for new homes and for replacement in existing dwellings. Most units are built-in, whereas others are free-standing and resemble a wood stove.
Gas fireplaces have the potential for reasonably efficient performance. However, the efficiency of models currently available on the market can range anywhere from 30 to 70 percent, when tested to the new Canadian standard (CSA P.4.1-02, "Testing Method for Measuring Annual Fireplace Efficiency"). If you are looking for a gas fireplace, ask for its CSA P.4.1-02 rating so you can properly compare different products.
ENERGUIDE RATING SYSTEM FOR GAS FIREPLACES
As of October 2003, an agreement between Natural Resources Canada and the Heating, Refrigeration and Air Conditioning Institute of Canada establishes an energy efficiency rating system for vented gas fireplaces. The EnerGuide rating system provides consumers with the assurance of a standardized method of testing, allowing them to accurately compare different makes and models. The testing provides a Fireplace Efficiency / FE rating based on products tested and certified to the Canadian Standards Association test standard P.4.1-02.
The standard assesses all gas fireplaces, whether they are decorative units or models used for space heating. It is an accurate measurement that reflects the overall operation of the fireplace, taking into account its use and performance throughout the entire heating season. The FE rating is expressed as a percentage; therefore, the higher the rating, the more efficient the unit.
In Canada, the FE rating is the only recognized measurement of the efficiency of vented gas fireplaces.
The EnerGuide Label for Gas Fireplaces
The EnerGuide Fireplace Efficiency rating will be found on manufacturers' product literature starting in the fall of 2003. The FE will be inserted in an easily identifiable EnerGuide label format and presented in one of two ways depending on whether the product literature lists only a single model or multiple models.
Figure 12 EnerGuide label for fireplaces (single model)
This EnerGuide label is found in product literature that features a single model. As noted in the rating system explanation above, the higher the percentage the more efficient the model.
Figure 13 EnerGuide label for fireplaces (multiple models)
This label is featured in product literature where multiple models with different FE ratings are shown. Each model number listed in the literature will identify the EnerGuide FE rating directly beside the model number.
Note the words "Based on CSA P.4.1-02" on both labels. This reference demonstrates that the FE rating is based on the testing method that all gas fireplaces sold in Canada must adhere to.
Energy Efficiency Consideration
If you are looking for a gas fireplace, consider the following points:
For more information, talk to your product representative, or call toll-free to order your free copy of All About Gas Fireplaces at 1 800 387-2000 or visit Natural Resources Canada's Web site at oee.nrcan.gc.ca/equipment.
Web Version of EnerGuide Gas Fireplaces Directory
A Web version of the EnerGuide gas fireplaces directory will be available by fall 2004. The directory will provide a list of all models of vented gas fireplaces for sale in Canada and will enable you to compare the energy performance and operating costs of similar models.
CARBON MONOXIDE DETECTORS
Because modern houses are more airtight and have more powerful air-exhausting systems, there is a greater chance that combustion products – sometimes containing deadly carbon monoxide gas – will build up inside your house to potentially dangerous levels. A certified carbon monoxide detector located close to fuel-fired appliances (such as furnaces, fireplaces, space heaters, wood stoves and gas or propane refrigerators) will signal a potentially dangerous situation that must be corrected immediately.
Symptoms of low-level carbon monoxide poisoning are similar to those of the flu – headaches, lethargy and nausea. If your carbon monoxide detector goes off, leave your home immediately, call your gas distribution company and seek medical attention.
If you have a conventional wood-burning fireplace (which can often leak carbon monoxide) and plan to use it fairly often, install a carbon monoxide detector near the fireplace.
Source: Natural Resources Canada (NRCan) - Office of Energy Efficiency