Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating. In industry, both hot water and water heated to steam have many uses.
In household and commercial usage, most water heaters in North America are of the tank type. Also called storage water heaters, these consist of a cylindrical vessel/container in which water is kept continuously hot and ready for use. Typical sizes for household use range from 75 to 400 litres (20 to 100 U.S. gallons). These may use electricity, natural gas, propane, heating oil, solar, or other energy sources. Natural gas heaters are most popular in the United States and most European countries, since the gas is often conveniently piped throughout cities and towns and currently is the cheapest to use. Compared to tankless heaters, storage water heaters have the advantage of using energy (gas or electricity) at a relatively slow rate, storing the heat for later use. The disadvantage is that after a while, the water inside the tank will cool down causing the heating system to activate to heat the water back up.
Adding insulation to your hot water tank is an easy way to save money and energy. In general, the more insulation the better, since it reduces standby heat loss. Water heaters are available with insulation ratings ranging from R-6 to R-24. It may be possible to add an extra insulating blanket or jacket on the outside of a poorly insulated water heater to reduce heat loss. The most common type of water heater blanket is fiberglass insulation with a vinyl film on the outside. The insulation is wrapped around the tank and the ends are taped together. It is important that the blanket be the right size for the tank and not block air flow or cover safety and drainage valves, the controls, or block airflow through the exhaust vent, if any. In very humid locations, adding insulation to an already well-insulated tank may cause condensation problems, potentially causing rust, mold, or operational problems.
Water circulating through a hot water circulation system becomes chemically inert and does not rust the piping. But water heaters have a constant supply of fresh water with lots of corrosion-causing oxygen. Because of this, water heaters are prone to corrosion. As a result, water heaters usually have an anti-corrosion rod or sacrificial rod installed. Sacrificial anodes are typically made of magnesium or aluminum. The rod is immersed inside the water heater tank, allowing the chemical reaction from the fresh water to attack it rather than the tank. In some areas, rods are replaced regularly.
One challenge in sizing a tankless water heater is to determine the demand in gallons per minute. The second challenge is determining what temperature rise is required for that flow. Because tankless water heaters are designed to accommodate a given maximum flow, there is a pressure loss associated with flows in excess of a unit's usable flow rating. In a house with a tankless water heater, it's possible to have a fixture with almost no flow of water if too many faucets are opened simultaneously. Occupants may have to adjust their expectations concerning when and to what extent simultaneous demands for hot water can be made before temperature and flow of hot water are affected.
Fuel-fired water heaters should not be installed in a room used as a storage closet. Fuel-fired water heaters cannot obtain combustion air from sleeping rooms, bathrooms or toilet rooms. There are two exceptions: 1) a water heaters located in a bedroom or bathroom could be installed in a sealed enclosure so that combustion air will not be taken from the living space, and a solid, weather-stripped door with a self-closing device should be provided; and 2) a water heater could be installed in a room that is not a confined space and the building is not of unusually tight construction.
If your hot water tank uses combustion air and is in a confined space then combustion air has to be supplied. If all combustion air is taken from the inside of the dwelling, then two permanent openings should be installed. One opening should be within 12 inches (305 mm) of the top, and the other within 12 inches (305 mm) of the bottom of the space. Each opening shall have a free area equal to a minimum of 1 square inch per 1,000 BTU/h (2,201 mm2/kW) input rating of all appliances installed within the space, but not less than 100 square inches (64,415 mm2).
When buying a new home you should have the building inspected by a Certified Home Inspector. The Barrie Home Inspector has performed over 4,000 home inspections and is qualified and trained to protect your next Real Estate Investment.
In household and commercial usage, most water heaters in North America are of the tank type. Also called storage water heaters, these consist of a cylindrical vessel/container in which water is kept continuously hot and ready for use. Typical sizes for household use range from 75 to 400 litres (20 to 100 U.S. gallons). These may use electricity, natural gas, propane, heating oil, solar, or other energy sources. Natural gas heaters are most popular in the United States and most European countries, since the gas is often conveniently piped throughout cities and towns and currently is the cheapest to use. Compared to tankless heaters, storage water heaters have the advantage of using energy (gas or electricity) at a relatively slow rate, storing the heat for later use. The disadvantage is that after a while, the water inside the tank will cool down causing the heating system to activate to heat the water back up.
Adding insulation to your hot water tank is an easy way to save money and energy. In general, the more insulation the better, since it reduces standby heat loss. Water heaters are available with insulation ratings ranging from R-6 to R-24. It may be possible to add an extra insulating blanket or jacket on the outside of a poorly insulated water heater to reduce heat loss. The most common type of water heater blanket is fiberglass insulation with a vinyl film on the outside. The insulation is wrapped around the tank and the ends are taped together. It is important that the blanket be the right size for the tank and not block air flow or cover safety and drainage valves, the controls, or block airflow through the exhaust vent, if any. In very humid locations, adding insulation to an already well-insulated tank may cause condensation problems, potentially causing rust, mold, or operational problems.
Water circulating through a hot water circulation system becomes chemically inert and does not rust the piping. But water heaters have a constant supply of fresh water with lots of corrosion-causing oxygen. Because of this, water heaters are prone to corrosion. As a result, water heaters usually have an anti-corrosion rod or sacrificial rod installed. Sacrificial anodes are typically made of magnesium or aluminum. The rod is immersed inside the water heater tank, allowing the chemical reaction from the fresh water to attack it rather than the tank. In some areas, rods are replaced regularly.
One challenge in sizing a tankless water heater is to determine the demand in gallons per minute. The second challenge is determining what temperature rise is required for that flow. Because tankless water heaters are designed to accommodate a given maximum flow, there is a pressure loss associated with flows in excess of a unit's usable flow rating. In a house with a tankless water heater, it's possible to have a fixture with almost no flow of water if too many faucets are opened simultaneously. Occupants may have to adjust their expectations concerning when and to what extent simultaneous demands for hot water can be made before temperature and flow of hot water are affected.
Fuel-fired water heaters should not be installed in a room used as a storage closet. Fuel-fired water heaters cannot obtain combustion air from sleeping rooms, bathrooms or toilet rooms. There are two exceptions: 1) a water heaters located in a bedroom or bathroom could be installed in a sealed enclosure so that combustion air will not be taken from the living space, and a solid, weather-stripped door with a self-closing device should be provided; and 2) a water heater could be installed in a room that is not a confined space and the building is not of unusually tight construction.
If your hot water tank uses combustion air and is in a confined space then combustion air has to be supplied. If all combustion air is taken from the inside of the dwelling, then two permanent openings should be installed. One opening should be within 12 inches (305 mm) of the top, and the other within 12 inches (305 mm) of the bottom of the space. Each opening shall have a free area equal to a minimum of 1 square inch per 1,000 BTU/h (2,201 mm2/kW) input rating of all appliances installed within the space, but not less than 100 square inches (64,415 mm2).
When buying a new home you should have the building inspected by a Certified Home Inspector. The Barrie Home Inspector has performed over 4,000 home inspections and is qualified and trained to protect your next Real Estate Investment.
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Looking to find the Barrie's Best Real Estate Agents, then visit www.barriesrealestateagent.com. Purchasing a Commercial Building, then use the services of Barrie's Commercial Building Inspector to ensure your investment is protected.
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