In this Chapter, we will describe in detail each of the four steps in the decision-making process for home heating.
It may be counter-productive to invest in a new or improved heating system, only to allow much of its heat to escape to the outdoors, due to an inefficient house envelope which needs more insulation or has many air leaks. To avoid this, take a look at where you can draftproof and insulate simply and effectively, before having a heating system sized, installed or upgraded.
There are many advantages to draftproofing and insulating. Heating the house will cost considerably less, and you will be more comfortable because of fewer drafts and warmer surfaces, such as walls. Your house will also tend to be cooler in the summer. Another benefit to draftproofing and insulating relates to humidity levels. Dry air in a house during the winter is caused by too much outside air getting in. Although the relative humidity may be high for cold outside air, the absolute amount of moisture or water vapour this cold air can hold is actually very low. When this air is brought inside and heated to room temperature, it becomes extremely dry.
If the air inside your house seems too dry, one of the simplest solutions is to add moisture, using a humidifier or an evaporator tray. However, the best way to increase humidity levels and lower heating costs is to reduce air leakage. In general, most airtight houses do not need a humidifier–the moisture generated through cooking, bathing, dishwashing, and other activities, is more than adequate.
However, with an airtight house, the reverse can occur. Making your house more airtight can affect the air quality inside. Unwanted fumes, odours, gases and too much humidity can be trapped inside the house envelope. One of the best ways to solve this problem is to install a fresh air intake or mechanical ventilation system that brings in and circulates fresh air, without causing drafts. Your serviceperson should be able to provide you with more information.
Insulating, caulking, and weatherstripping will reduce the amount of heat needed to keep your house comfortable. If your home has not been thoroughly reinsulated and draft-proofed, you should consider doing it before changing or modifying the heating system. For more information about draftproofing and insulating, order a free copy of Keeping the Heat In (see page 52). Whether you plan to do the work yourself or hire a contractor, this publication explains the details (including proper insulation levels) and can help make the whole job easier.
To ensure that you get a heating system with the right heating capacity, be sure to draftproof and insulate before you and your contractor determine what size of heating system and equipment is best. In general, oversized furnaces will waste fuel unnecessarily, because they tend to operate in frequent, short cycles. They may also decrease comfort because of the resulting excessive temperature fluctuations.
If you are buying or building a new house, insist on the R-2000 standard. R-2000 Homes have high levels of insulation, airtight construction, heat-recovery ventilators, energy-efficient windows and doors, efficient heating systems, and other design features that cut heating requirements by an average of 25 per cent compared with conventional construction. The house is more comfortable to live in, and a high quality product is ensured. For more information on R-2000 Homes, see page 51 or contact your provincial Home-builders' Association.
The next step is to select the heating energy source that is right for you. Generally, your options include natural gas, oil, propane, electricity, or wood. You may also choose a combination of these conventional energy sources or alternatives, such as solar energy. Your decision regarding the most appropriate energy source should be based on a number of considerations, the most important of which are described below:
ENERGY AVAILABILITY CONSIDERATIONS
Not all energy sources are available in all areas of Canada. Electricity and heating oil are generally available in most places, but natural gas, which must be delivered by pipeline, is not available in much of the Atlantic region or in many rural and remote areas of other provinces. Propane is available in most parts of Canada and may be used in rural or cottage areas as a substitute for natural gas or fuel oil, although often at a significantly higher cost. In many areas, wood is a cost-effective complement to your conventional heating system. Check with your local fuel supplier, gas or electrical utility to find out which energy sources are available in your area.
For most homeowners, the major factor in the home heating decision is cost. This particular factor consists of two major components–the capital cost of the installed heating system and the annual operating cost for energy. Other factors, such as maintenance costs, cleanliness, and noise of operation, should also be considered.
Some of the major installation capital costs of different heating systems, depending on whether they are new or retrofitted, include such items as:
The capital cost of a heating system can range from as low as $1,000 for baseboard heaters in a small house to as high as $12,000 or more for a ground-source heat pump for a larger home which is capable of providing heating, air conditioning, and hot water. Heating contractors or utility representatives can give you an estimate of the capital cost of various systems. Always ask for a firm quote before you authorize any work.
The apparently inexpensive initial cost of electric baseboard heating has resulted in the majority of electrically heated homes in Canada being of this type. Today, with much higher electricity rates, the annual cost to heat such a home has become quite high. Once installed, it is fairly difficult and costly to convert to a different energy source and heat distribution system.
The operating or fuel cost of a heating system is determined by the following three major factors:
|The heating load or heating requirements of the house. This depends on climate, size and style of house, insulation levels, airtightness, amount of useful solar energy through windows, amount of heat given off by lights and appliances, thermostat setting, and other operational factors. Together, these factors determine the amount of heat that must be supplied by the heating system over the heating season. This number, usually expressed as Btu, kWh or MJ per year (see page 35), can be estimated by a competent heating contractor, homebuilder, or utility representative.
|Choice of energy source and its unit price. Each energy source is measured and priced differently. Electricity is priced in cents per kilowatt hour (¢/kWh), oil and propane in cents per litre (¢/L), natural gas is priced in cents per cubic metre (¢/m3) or in dollars per megajoule ($/MJ), or dollars per gigajoule ($/GJ), and wood in dollars per cord. You must consider the heat content of the various energy sources to determine the most cost-effective energy source for your area. Check with your local utility or fuel supplier for the unit prices of energy sources in your area. Table 1 on page 35 gives the energy content for the various energy sources in the units in which they are commonly sold.
|Equipment efficiency. The efficiency with which the appliance converts the energy source to useful heat in the home is also an important factor in the heating cost equation. For example, if a furnace has an AFUE (see page 36) of 80 per cent, then 80 per cent of the heat value in the fuel is available. The other 20 per cent is lost, mostly up the chimney. Thus, additional fuel must be consumed to make up for these losses. Improving the efficiency of the heating equipment reduces energy use and cost.
The combination of heating load, fuel choice, and equipment efficiency determines the annual cost of heating. A detailed description of how you can calculate heating costs for various energy sources and technologies is given in Chapter 3, page 34 along with typical seasonal efficiencies (AFUE) for a range of technologies.
In the end, a homeowner thinking about a new heating system must balance the capital cost against the operating cost and make the best financial decision, taking into consideration how energy prices might change in the future. Since annual operating costs (and the differences in operating costs with different technologies) are very significant compared to capital costs, an investment in high-efficiency equipment is often very wise.
The effects of energy production and consumption play an important role in many of today's key environmental problems. Exploration and extraction for fossil fuels in fragile ecosystems, fuel spills and leaks during transportation, urban smog, acid rain problems, and global warming–all can have an adverse affect on our environment. Each form of energy has a different impact at various points in the energy cycle. No form of energy is completely harmless, although the environmental impacts of some sources of supply, such as passive solar energy, are relatively insignificant.
Heating your home can affect the environment in different ways, from gases leaving the chimney, to emissions at a coal-fired generating station, to flooding vast stretches of land during the construction of a remote hydroelectric site. The overall environmental impact is determined by the amount and type of fuel your heating system uses.
Selecting the cleanest energy source is within your power–but this is often a complex assessment that may vary between regions in Canada. The combustion of natural gas, propane, or fuel oil in your furnace releases various pollutants into the local environment.
While it is easy to blame pollution on combustion products from your fuel-fired heating system, it becomes more complex when electricity is involved. Electricity is clean at the point of use, but it has environmental impacts at the point of generation. In the provinces of Alberta, Saskatchewan, New Brunswick, Nova Scotia, Prince Edward Island, Newfoundland, and Ontario, coal or heavy oil is burned to meet electricity demands during the winter. In other provinces–Manitoba, British Columbia, and Quebec–where winter peak demand is met by hydroelectric power, the environmental impact at the point of generation is much less obvious. However, in some instances, emissions of methane can be high in major hydro dam projects. Nuclear power has its own set of environmental problems.
In short, there is no easy solution but by buying an efficient system with the most appropriate energy source for your area, you can make a major contribution to environmental health. Other approaches that can help you do your part to reduce energy use and its impact on the environment include improving insulation and airtightness, while ensuring proper ventilation, maintaining your heating system, installing setback thermostats, and improving your heat distribution system.
Most heating systems today are either forced-air systems or hot water (hydronic) systems. These systems consist of a heating unit (furnace or boiler), a distribution system (ducts and registers, or pipes and radiators), and controls (such as thermostats) that regulate the system. Some houses use space heaters and do not have distribution networks.
By far the most common type of central heating system used in Canadian homes is a forced-air system, with a furnace as the heat source. Among its advantages is its ability to provide heat very quickly; the fact that it can also be used to filter and humidify household air, and its ability to provide ventilation and central air conditioning. In addition, the furnace fan can be used year-round to provide continuous air circulation throughout the house, while efficiently balancing the distribution of heat in colder months.
Forced-air systems also have some disadvantages. The air coming from the heating registers, can sometimes feel cool, especially with certain heat pumps, even when it is actually warmer than the room temperature. The effect is much the same as the cooling action of a fan or a summer breeze. In addition, there can be short bursts of very hot air, especially with oversized systems. Some people find these characteristics uncomfortable. The ductwork that distributes the heat may also transmit the noise of the furnace and its circulating fan, and can circulate dust as well as cooking and other odours throughout the house. Consult your heating contractor for further information.
HYDRONIC HEATING SYSTEMS
A hot-water or hydronic heating system uses a boiler to heat water, which is then circulated through the house before returning to the boiler to be reheated.
Contemporary hydronic heating systems typically produce and circulate hot water at approximately 82oC (180oF) in a closed system.
Hot water or steam heating systems once had large boilers and used wrought-iron pipes and massive cast-iron radiators; many of these are still around in older homes. For many years now, installers have been using thinner copper piping, slim baseboard heaters, and smaller, more efficient boilers. Recently, CSA-approved plastic piping has become available as an alternative to copper piping for space heating and service hot-water distribution.
Figure 1: Hydronic heating system
OTHER TYPES OF SYSTEMS
Apart from the more popular systems noted above, others that can be used independently or in combination with conventional systems are also available. These include room space heaters, radiant space heaters, and built-in radiant systems.
Room space heaters provide heat directly to the rooms in which they are located and do not have a central heat distribution system. Obvious examples are wood stoves, vented oil-fired space heaters, and electric or gas-fired baseboard heaters.
Some space heaters can also be very effective radiant heat sources, warming solid bodies (like people) in their line-of-sight without necessarily having to heat up all the ambient air. Good examples are the new direct-vent gas fireplaces, advanced combustion wood fireplaces and portable electric infrared radiant heaters. If properly located in a major living space, a radiant space heater can actually act as an effective auxiliary heating system, lowering the overall heat requirements of the house and the heating bill, while making the occupants feel more comfortable.
Built-in radiant systems are generally of two types: hot water pipes in floors or electrical cables in floors which may also be installed in ceilings. The radiant floor type, becoming increasingly popular, consists of narrow hot water pipes embedded in the floor. Hot water at around 40oC (104oF) is pumped slowly through the pipes and radiates heat into the house. Thick carpets can reduce effectiveness significantly by acting as insulation. Such a system may be more costly to install and does not appear to offer much in energy savings. However, some radiant floor installations may offer comfort benefits, resulting in lower thermostat settings and reduced heating bills.
Your choice of a heat distribution system may be limited if you have a warm air or hydronic system already in place. If you have electric baseboards and are faced with high heating bills, you may wish to change to another type of system, even though it can be an expensive undertaking. Your final choice will probably be based on your answers to one or more of the following questions:
HEATING WITH ELECTRICITY – WHAT ARE YOUR OPTIONS?
Electricity can be used as the sole heating source or in combination with other sources in a home heating system.
The five basic types of electric heating systems available in Canada are as follows:
An increasing number of homeowners with electric baseboard heating are switching to other energy sources, such as natural gas, oil or heat pumps, because of the high cost of electric heating. While a major constraint is the lack of a distribution system, many homeowners find that air ducts for a central forced-air system, or pipes and radiators for a hydronic system, can be installed at a cost that still makes the whole conversion financially attractive. Fuel-fired space heaters, wood stoves, and advanced, energy-efficient wood-or gas-fired fireplaces can also be effective.
Once you have selected your energy source options and your heat distribution system, you can begin to consider your alternatives regarding heating equipment and efficiency levels. At some point in your evaluation, you will have to consider whether to upgrade your existing heating equipment or to replace it entirely. A number of things can be done to improve the efficiency of an existing heating system. You also have the choice of several different replacement models with various efficiency ratings and prices.
Here are some details to consider when choosing your equipment:
Equipment Efficiency and Suitability
Refer to Chapters 2 and 4 of this booklet for a more detailed discussion of your options for electric heating.
Purchase, Installation, Operation and Maintenance Costs
Generally, the efficient heating systems have a higher capital cost. This must be kept in mind when considering any changes or new equipment purchases. In short, you will want to make sure that the reduction in energy consumption and enhanced comfort will reimburse your improvement costs within a reasonable time. More often than not, they will.
Servicing and Guarantees
It is also important to know the type and frequency of servicing your system requires, the price of parts, cost of servicing, and details of guarantees and warranties, such as the period covered, and if parts and labour are included. Before you finally decide on a particular model or type of furnace, ask the seller to give you the names of a few people who have bought this equipment, and ask for their opinions.
The federal government has implemented energy-efficiency standards for some heating equipment and other energy-consuming appliances and products. Various provincial governments have also introduced energy-efficiency standards, and other provinces have stated their intention to follow suit. Generally, these standards establish the minimum acceptable energy efficiency for specific types of heating equipment. Once the standards are in place, low-efficiency models that do not meet the standard are no longer allowed on the market in that particular jurisdiction.
Depending on where you live, you may have some difficulty finding the type of furnace, heat pump or boiler you want. This is because the manufacturers' distribution networks may not be developed for all models in all parts of Canada or because certain models have been discontinued due to government minimum-efficiency standards.
Source: Natural Resources Canada (NRCan) - Office of Energy Efficiency