Hot Water and How to Heat It
There are several water-heating options available to you. While you are taking steps to save on home heating, don’t forget to see what you can do to lower your water heating costs. Check with your fuel supplier for more information, and consider alternatives to your current method.
Storage-type water heaters
Most homes have storage-type water heaters in which water in a tank is heated by a gas or oil burner or by electric elements. Traditional storage heaters have been improved with such features as through-the-wall venting for combustion units and better insulation, making them less expensive to operate. Units designed to give even greater efficiency are now available.
Instantaneous water heaters
Instantaneous water heaters which heat water as needed and have no storage tank are available, but not widely. They require little space, but they usually cost more than storage-type water heaters and more than one unit might be required to meet your needs. For electric instantaneous water heaters, upgraded wiring is often necessary.
Integrated (combination) hot water systems
Systems that combine space heating and water heating are becoming more popular. Water can be heated with a boiler or a storage-tank water heater. The hot water can be used for space heating as well as domestic hot water needs. Space heating methods include baseboard radiators, in-floor radiant heating and forced air heating when piped to an air handler. Some of these systems can also be used for pool and spa heating and snow-melting applications. Combo systems vary widely in efficiency and must be carefully designed to give satisfactory service.
Solar water heaters
In solar water heaters, energy from the sun is collected by solar panels and transferred by circulating fluids to a storage tank. These heaters are typically used with an electric water heater, or one fueled by oil, natural gas or propane, which acts as a back-up for overcast days. Solar collector panels can be mounted on any unobstructed roof, wall or ground frame that faces between
southeast and southwest. Solar water heaters are designed to provide between 35 and 75% of your hot water needs, with the back-up providing the balance.
Replacing Your System
Review your options, consider the pros and cons of different equipment and fuels, and compare installation and operating costs. Now get ready to improve your existing system, and it’s time to select a contractor. Here are some tips:
- Look for a registered contractor
- Get estimates from several contractors.
Prices can vary significantly among contractors. Ask each firm for a written estimate covering the following items:
- The total cost and a listing of all necessary work including improvements to the existing system and the provision of combustion air if applicable
- Heat loss/gain analysis
- The size and seasonal efficiency of the unit, and sound ratings if applicable
- Responsibility of the contractor or
- Obtaining permits and paying related fees
- Removing and disposing of old equipment
- Arranging for such work as installation of gas supply
- Arranging necessary inspections
- A work schedule and completion date
- Guarantees, warranties and service contracts
- Terms of payment
- Evidence of an electrician’s licence as appropriate
Use costs (both installed and operating), work schedule, warranties and service as the basis for your decision. Ask the contractors you are considering for references, and follow up by contacting previous customers. Ask what they think about the contractor, fuel supplier and the options you are considering.
- Choose the right equipment
In order to correctly size new heating and cooling equipment, your contractor must analyze how much heat is lost from your home in winter and gained in summer. Ask for this heat loss/gain analysis in writing, including the method used to perform the calculation. This calculation should take into consideration such factors as the size of the house, its level of insulation and the condition of windows and doors. If the heat loss and gain is significant and you haven’t already taken steps to increase the energy efficiency of the house, now is the time to do it.
Avoid the temptation to simply choose the same size equipment that already exists in your house without doing a heat loss/gain analysis. Your home has likely been altered over the years
and the system might even have been the wrong size at the start. An oversized unit will usually operate below peak efficiency, and both oversized and undersized units can adversely affect the
comfort of your home. Any installation involving
combustion equipment should include steps to ensure that there will be an
adequate supply of air for combustion and venting, and that other air exhausting
equipment will not cause problems.
Changing Your Water Heater
Size is an important consideration when selecting
new hot water equipment. A larger family is likely to use more hot water. A
“downsized” household – for example, an older couple whose children have grown
up and moved into their own homes – will no longer need a water heater meant to
supply the needs of four or more people. By practicing water conservation – for
example, by installing energy-efficient showerheads and aerators on taps and
using cold water in your washing machine – you can substantially reduce your hot
Steps to installing a hot water tank
Contact your local fuel supplier or contractor and ask for the efficiency ratings of the models you are considering. When you have selected a unit just big enough to meet your household needs, your fuel supplier or contractor can arrange for a qualified serviceperson to install the water heater. If you have an electric hot water tank, wrap it in an insulating blanket. Make sure the blanket is certified for use on your heater and is properly installed. Insulate both the hot and cold water lines of the tank and consider installing a heat trap. Be careful not to insulate the pipes too close to the flue of a fossil-fueled tank. Ask your fuel supplier about any water heating cost-saving programs they offer. Some suppliers do some of the work at little or no cost to you.