I’m planning a hybrid heating system for my home and would greatly appreciate input from experienced plumbers and heating engineers to validate my approach.
Here's an outline of my setup and reasoning:
System Overview
Heat Source: Combi boiler with an integrated pump, set to supply a single flow temperature of 45°C.
Heating Circuits:
Underfloor Heating (UFH): Covers communal areas (living room, kitchen, diner, and snug).
Radiators: Installed in bedrooms, bathrooms, and other spaces, all sized to meet heat loss requirements at 45°C.
Manifold: Single manifold shared between UFH and radiator circuits, with manual flow valves for each loop to adjust flow rates and balance the system.
No Additional Pump or Mixing Valve: The combi boiler pump circulates water to both UFH and radiator circuits directly through single manifiold.
Design Considerations
The entire system is designed to meet the required heat loss for each room at 45°C.
All radiators are carefully sized to deliver sufficient heat at this low flow temperature.
Flow valves on the manifold are used to manually balance the system and ensure the correct temperature difference (ΔT) between flow and return in each loop.
Heat emitter overrides have been accounted for, where excess capacity in adjacent rooms compensates for shortfalls.
Room-by-Room Summary (Based on my design report)
Bedroom 1:
Heat Loss: 530W; Emitter Output: 345W at 45°C.
Adjacent rooms provide 967W excess, compensating for the shortfall.
Bedroom 2:
Heat Loss: 468W; Emitter Output: 387W at 45°C.
Adjacent rooms provide 782W excess, compensating for the shortfall.
Bedroom 3:
Heat Loss: 185W; Emitter Output: 173W at 45°C.
Adjacent rooms provide 701W excess, compensating for the shortfall.
Living Room (UFH):
Heat Loss: 976W; Emitter Output: 1283W at 45°C.
Heat loss fully met by UFH.
Kitchen/Diner/Snug (UFH):
Heat Loss: 1347W; Emitter Output: 1773W at 45°C.
Heat loss fully met by UFH.
Bathroom:
Heat Loss: 401W; Emitter Output: 215W at 45°C.
Adjacent rooms provide 689W excess, compensating for the shortfall.
Specific Questions
Is my assumption correct that, since the system operates at a single flow temperature of 45°C, I can avoid additional pumps or mixing valves for the UFH?
Do the manual flow valves on the manifold suffice for balancing the system, or would you recommend a different approach?
Are there any practical considerations I might have missed when combining UFH and radiators in a hybrid setup at this flow temperature?
Based on the provided room-by-room heat loss and emitter outputs, do you foresee any operational issues with my proposed system?
Thank you in advance for your feedback! I’d love to hear any thoughts, suggestions, or potential improvements from those with experience in designing or installing similar systems.