Solar thermal systems have recently been shown to be cost-competitive with natural gas for multi-unit housing. As a result, architects and developers are increasingly contacting Free Hot Water to find out if solar water heating systems can be integrated with their designs for new apartment buildings, hotels, hospitals, nursing homes, or student dormitory projects.
To give an accurate answer, solar thermal engineers need specific data in order to determine the solar potential, cost, and ROI. To facilitate the proposal process, Free Hot Water has created a comprehensive checklist of information needed to create an accurate solar water heating design and cost estimate for multi-unit dwellings.
The information needed includes:
THE SITE LOCATION
The building’s address
Free Hot Water engineers will need this to remotely check your annual insolation—the yearly amount of sunlight that will potentially hit the roof of your project. It’s also important for permitting and other factors.
Do you have a southern oriented roof?
In North America, the sun crosses the horizon in southern orientation, which is optimal for solar thermal production. Your roof can face east or west, as well, but southern exposure is best. For flat roofs, this can also be a concern when taller surrounding buildings block the sun.
The locations of any buildings or trees that may cast shade on panels
If your landscape design will include trees or you’ll have other buildings that may block sunlight, we will need to account for this in our designs.
The number of floors
Knowing the number of floors is important for designing pump stations that are strong enough to circulate the solar thermal fluid throughout the building.
The building’s footprint with dimensions
We’ll need this to account for the number and type of solar thermal collectors, piping, as well as other considerations.
Design images of the building from the side view
Free Hot Water engineers endeavor to make pipes and other external solar infrastructure as unobtrusive as possible, so it’s important for us to see the potential areas where pipes or storage tanks can be placed.
Specific roof dimensions will help engineers to design the most optimal solar thermal system within the available area. Therefore, it’s important for us to have the following dimensions:
Roof slopes (for example, 4:12), hips, peaks and valleys
Locations & footprint dimensions of all rooftop equipment to be avoided (HVAC vents, skylights, etc.)
Please identify any rooftop equipment that may cast shade on solar panels
Roof framing information (size and locations of roof framing members, roof deck type, etc.)
If applicable, please indicate the roof section where you would like the solar collectors to be installed. If flexible, we will suggest the best area.
STORAGE TANK LOCATION
Solar thermal storage tanks can be placed indoors, outdoors, or even underground.
Storage tank location
If storage tanks can be placed outdoors, we will need the dimensions of the area where tanks are to be located, as well as adjacent structures, etc. If indoors, we’ll need to know the location of the mechanical room in the current design.
Plan dimensions of all walls outlining mechanical room
This will determine the potential for the potential volume of solar hot water storage and space needed for other equipment, such as the pump station and backup heating tanks.
Location and size of all wall openings (doors, windows, louvers, etc.)
Storage tanks come in different shapes and sizes. We’ll use this information to determine the type and size of storage tanks that can be brought through the doors or other access areas.
Similarly, we’ll also need the ceiling height in order to ensure that the room’s height is adequate for tank clearance.
Location and size of all other equipment planned for the mechanical room If other equipment needs to be housed in the same mechanical room, we’ll need a list of these items. (boilers, pumps, tanks, machinery, washers, dryers, wall-mounted equipment, etc.)
If storage tanks will be mounted on an existing or pre-designed slab, we will need slab information (depth, reinforcing, etc.) Alternatively, your solar thermal engineer can design the correct size slab.
We’ll need the call out pipe diameter of city water inlet and domestic hot water outlet for the building.
IF REQUIRED BY BUILDING DEPARTMENT:
Depending on your city’s permitting requirements, we may need the elevation view(s) of building (with dimensions, or in a scalable format)
Do the solar hot water controls need to be tied into the building controls? Or can they operate independently? Free Hot Water’s engineers can design control and maintenance solutions for both options.
Of course, depending on your architectural and budget goals, your solar thermal engineering team may need additional data or specifications. If you’d like to know more, please contact Free Hot Water for a free solar thermal engineering consultation.