The Essentials About Solar Water Heating Systems For Homes
Solar water heating systems for homes have become quite common. These systems preheat the incoming cold water to be used in baths, kitchen and to do laundry. When sized correctly, a solar water heating system will supply about 40-70% of your hot water demand. In order to qualify for the currently available federal tax credits however, your system must provide at least 50% of your water needs. Combine these tax credits with the increased efficiency of modern systems, and it has become very feasible for many homeowners to have a solar water heating systems.
Two types of solar domestic hot water heating systems are used in residential applications: the closed loop system and the open loop system. A closed loop system separates the collector loop from the domestic water side with a heat exchanger: the domestic water system is closed to the solar collectors. A freeze-proof liquid, usually a glycol solution, is circulated through the solar collectors and the heat exchanger, which is located in the solar storage tank. These systems are also recommended for areas with hard water. Closed loop systems unfortunately cost more than an open system. People living in areas where temperatures always remain above freezing can install open loop systems. The domestic water loop is open to the solar collectors and the incoming cold water is circulated directly through the solar collectors and then to the solar storage tank.
Number and size of solar collectors will be selected based on the type of collectors, where you live and on your hot water demand. Solar collectors for water heating most frequently installed are flat plate or evacuated tube collectors. Evacuated tube collectors have a higher efficiency than the flat plate collectors and are recommended for colder or cloudy climates and regions with hard water. You will pay a premium however, for the higher efficiency evacuated tube collectors.
It is essential to mention that a solar water heating system will not replace your existing domestic water heater or eliminate the necessity for installing one in a new home. The intent of the regular water heater is to make sure that you have sufficient hot water during and after several cloudy days. A complete solar heating system must include a solar storage tank. This tank is used to hold the water that was (pre)-heated in the collectors. The (pre)-heated water then flows from the solar storage tank to the regular water heater where it is heated up as needed. The regular water heater will not need to run on most sunny days, if the solar heating system is designed well.
I guess you will put the solar collectors somewhere on the roof of your home. The location of the collectors is the most important decision you will make. Insufficient direct sunlight will make the best system perform poorly. Choose well! If you need someone to help you, call a local solar system installer (they just might do a free analysis for you), or buy/rent a solar radiation tool and do it yourself. Always remember to include any trees that shade your roof.
So now you have determined where the solar collectors will be installed on your roof. You hope. Because next you will have to make sure that the roof can support the collectors and the frame, at that particular spot. Talk to a contractor, to see what, if any roof strengthening and additional framing will be required. Also make sure that you know what needs to be done to make sure the roofing will remain waterproof.
Ok, let’s look what is needed in the house. Here you will need space for the solar storage tank, pump and possibly a small expansion tank, if you end up with a closed loop system. How much space? For initial planning purposes, allow at least 2 1/2 times as much space as your existing water heater uses. This needs to be adjacent to the water heater. And make sure that you will have easy access for maintenance.
All right, the collectors are on the roof, the solar storage tank is in the basement. How will you run the pipes between the two? You will have to run two 3″ pipes. That is based on 1″ pipes with 1″ insulation. investigate which walls you can use to run the pipes up through, all the way from the basement, or first floor, to the roof. You want to avoid having to build pipe enclosures. That can get costly and might not look very nice. Corners in built-in closets are great places to tuck a set of pipes into.
Done. At least with a lot of the important initial research. Use the knowledge you will have gained after answering all the questions raised. You are now in a good position to either know what else you need to know to be able to design and install a solar hot water system for your home yourself, or hire a contractor for the work.
Avoid the same mistakes other folks have made before you when they were planning, designing and installing a solar hot water system. Get educated and learn how to plan and prepare for a successful system.
