Solar Pool Heating Retrofit
Solar Pool Heating Repair & Optimization
This municipal pool heating system had so much potential: new condensing gas boilers, a modern DDC system, and a large solar thermal array. Unfortunately it also had some serious issues: energy savings weren’t being achieved and the maintenance staff were struggling to control the pool water temperature. The new boiler plant had plenty of power, but was unable to heat the pool effectively. The maintenance staff had to start heating the outdoor pool a month early, because it was taking so long to warm up!
Stage 3 Renewables solved the problems, improved the system, and got the facility back on track with energy savings and stress-free operation. Our innovative approach provided exceptional value because the client only had one point of contact, and one company responsible for the result. The usual fragmented approach: hiring consulting engineers, a mechanical contractor, and a controls company; involves lots of risk and costs much more. The building owner is often left with 3 different companies pointing fingers at each other when something doesn’t work.
Stage 3 Renewables assessed the facility, identified the issues, and then implemented the necessary changes. We handled the whole project, and the client was very happy with the process and the result.
Solar Pool Heating Issues
- A large unglazed solar pool heating system on the roof wasn’t functioning or saving any energy. Stage 3 Renewables implemented numerous fixes to get the solar system performing as it should.
- The solar connection to the pool water supply was plumbed downstream of the boilers, so effective solar heating was impossible. We re-plumbed the pool water to solar before it returned to the boilers.
- The solar array was also introducing impressive bubbles into the pool water on startup. The collectors were draining down between cycles, so we installed a calibrated pressure sustaining valve to fix this issue. The solar now runs quietly and bubble free.
- The pool water temperature sensor was in the wrong location, so the DDC wasn’t backing the boilers off and allowing solar to pick up the load. We changed the sensor location and ‘smartened’ up the DDC logic to ensure that solar heating was maximized.
Boiler and Pool Heating
- The boiler piping and valve layout had fundamental errors that were causing the performance issues. We modified some of the pipework and rewrote the control strategy for the mixing and diverting valves.
- One pump was attempting to supply boiler water to the pool and DWH heat exchangers. They weren’t getting the design flow rate, so the boilers ran for long hours without effectively adding heat to the loads. Stage 3 installed balancing valves to achieve design flow rates.
- The load side of the pool heat exchanger was relying on backpressure from a butterfly valve to establish flow. This flow rate was highly variable as the pool filter condition changed. We installed a dedicated pump and flow indication to ensure the boilers could add heat to the pool.
DHW & Boiler Short Cycling
- The hot water for showers had no storage capacity, so these large boilers were acting as on-demand water heaters for the showers.
- We added a 119USG storage tank to reduce boiler short cycling for DHW.
Although the changes were numerous, the project budget was modest; especially compared to the results. By handling the troubleshooting, engineering, mechanical & plumbing, and the controls all under one roof; we were able to ensure this project was a success.
Stage 3 Renewables has a proven track record of fixing and optimizing complicated systems. If you have an underperforming mechanical system, we can help.
Stage 3 Renewables provides design, installation, and optimization for renewable energy systems. We cover Greater Vancouver, the Fraser Valley, Sunshine Coast, Vancouver Island, and the Gulf Islands
What We Do
Stage 3 Renewables is an innovative renewable energy company with an excellent reputation.
- Design / build & Project Management
- Energy modelling and pre-feasibility studies
- Engineering design and documentation
- Troubleshooting and repair of mechanical systems - we can fix it!
- New construction and conversions to Renewables