Points to consider before buying and installing a solar water heating system
Considering the solar resources of your location is of utmost importance before you buy and get a solar water heating system installed at your premise. Along with analyzing the solar resource, you must ensure standardized, optimal tilt and orientation of your solar collector. The design and efficiency of a solar water heating systems depends largely on the amount of solar energy reaching the system installed at your site.
Solar water heaters use both diffuse and direct solar radiations to heat water. Even at locations where the climate is mostly not as sunny and warm as mostly desired, such as the southern-west regions in the US, you might still have adequate solar resources. In case your premise particularly faces south and has ample unshaded areas, it makes a decent location to get a solar water heating system installed. It is recommended that you get your site analyzed by a certified solar hot water system supplier and manufacturer to avoid last minute surprises.
The tilt as well as the specific orientation of your solar collector will influence the efficiency of your solar hot water heating system. Your supplier should take into account both these influential factors while assessing the solar resource availability at your location and the sizing of your hot water system.
Solar collectors must be geographically oriented to max out the exposure to seasonal as well as regular solar power they receive. In general, the optimal solar collector orientation for a collector needs to be true south in the northern hemisphere. However, various studies conducted of late have revealed that depending upon the tilt of your collector and your site location, you hot water collector can easily endure up to 90º east or west of true south without visibly evident its performance drop.
You'll also want to consider factors such as roof orientation (if you plan to mount the collector on your roof), local landscape features that shade the collector daily or seasonally, and local weather conditions (foggy mornings or cloudy afternoons), as these factors may affect your collector's optimal orientation.
Many collectors used in solar water heater systems are mounted horizontally on the roof. It can sure be more appealing as compared to rack-mounted collectors that bulge out from your roof at odd angles. Consequently, most contractors ensure the roof and the collector have the same angle and tilt.
Though the optimum angle for the collector tilt is ideally equal to the latitude, installing your collector horizontally on a roof tilted to a certain angle will not impact the performance of your collector, by and large. However, you must consider the roof angle while deciding the size of your hot water system. In general, systems having steep angles on the solar collectors tend to provide more water heating during freezing conditions.
Safety – ensure enough fastening
Safety is a major point to ponder when installing a roof-based collector. Your contractor must ensure proper fastening of the tank and collector with your concrete structure. The best practice to secure fastening is by screwing the collector array right across your roof to the underlying timber purlins.
Likewise, all inlet and outlet pipes must be firmly secured. You must also consider the compatibility of the fastening metal being used with the system’s brackets and frames, etc. since corrosion can be a major concern if the combination of metals is not chosen wisely.
Ensure durability by avoiding corrosion
Materials used to fasten a typical solar water heater setup can be impacted by moisture in the air or water as such, along with various other environmental factors that may lead to your system getting vulnerable to worn outs or corrosions. Even solar UV rays can play a spoilsport and hamper the durability of your system. Other major factors from which you should safeguard your water heating system include heated water, contaminated water, sea rain, and of course, incompatible metal combinations.
The bottom line:
While you can ensure most of the factors and to-dos discussed in this post yourself, an expert recommendation and site inspection is suggested to make sure you get your solar water heater system set up firmly and that all possible performance or durability roadblocks are taken care of in the right manner.