1. Preliminary Considerations (Before Installation)

a) System Planning & Design

Determine hot water demand (number of occupants, bathrooms, kitchen use).

Select correct solar heater type (pressurized vs non-pressurized).

Confirm tank capacity (commonly 150L, 200L, 300L for homes).

Plan pipe routing to minimize distance between heater and outlets (reduces heat loss).

b) Site Assessment

Ensure roof strength can support tank and collector weight.

Confirm sun exposure (north-facing in Kenya, minimal shading).

Identify entry points for hot and cold pipes into the house.

Check distance from heater to bathrooms/kitchen.


c) Pipe Material Selection

Use heat-resistant piping:

PPR (PN20 or PN25)

Copper (best but expensive)

Multilayer PEX rated for hot water


Avoid low-grade PVC for hot water lines.


d) Plumbing Layout Preparation

Separate hot and cold water lines clearly.

Plan for:

Main hot water trunk

Branch lines to each outlet


Mark pipe paths before wall chasing or slab casting.


e) Safety & Compliance

Check local plumbing codes and standards.

Plan for pressure control (especially for pressurized systems).

Include space for valves, unions, and future maintenance access.



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2. Key Measures During Installation

a) Pipe Installation Best Practices

Maintain gentle bends (avoid sharp angles).

Use proper pipe clips/supports to prevent sagging.

Allow for thermal expansion, especially on long hot water runs.

Keep hot pipes away from electrical conduits.

b) Insulation Measures

Insulate all hot water pipes, especially:

Roof-exposed sections

Long horizontal runs


Use:

Closed-cell foam insulation

UV-protected insulation for outdoor pipes

This reduces heat loss and improves efficiency.

c) Pressure & Temperature Control

Install:

Pressure reducing valve (PRV) if supply pressure is high.

Temperature & Pressure Relief Valve (TPR) on the tank

Ensure safe discharge piping from TPR to a drain point.


d) Valves & Control Points

Install essential valves:

Main cold-water isolation valve to the heater

Non-return valve (prevents backflow)

Drain valve for system flushing

Individual isolation valves for major branches (optional but recommended)
e) Proper Gradient & Drainage

Maintain a slight downward gradient for easy draining.
Avoid trapping air pockets in horizontal runs.
Ensure outdoor pipes are protected from rainwater ingress.

f) Connection to Fixtures

Use flexible connectors at fixtures where possible.

Clearly label hot vs cold outlets.

Test for correct hot-water orientation (hot on left).

3. Testing & Commissioning

a) Pressure Testing

Test system with water before closing walls or ceilings.
Check all joints for leaks under operating pressure.

b) Temperature Testing

Verify hot water reaches outlets within reasonable time.

Confirm no overheating at taps (consider mixing valve if needed).

c) Final Insulation & Protection
Insulate any exposed joints after testing.

Protect roof pipes from:

UV damage

Physical damage

Birds or rodents

4. Maintenance & Future-Proofing Measures

Leave access panels for hidden valves.

Label main shut-off points.

Provide a bypass option for future electric or backup heater integration.
Keep an as-built plumbing layout for reference.