Pulse modulated heating, ventilation, and air conditioning (HVAC) control
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Solution Overview
Problem
Traditional heating/cooling systems with hydronic emitters, such as underfloor heating systems, take excessive time to raise room temperature due to low flow temperatures and restricted flow rates, preventing temperature setbacks and potentially damaging certain floor materials.
Innovation Solution
Pulsing the flow rate through hydronic emitters, controlled by a controller assembly, to modulate water flow, allowing heated water to fill the circuit and then stopping it for a fixed time, maintaining a lower floor temperature and supporting multiple rooms with different temperature limitations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If constant water flow is maintained through hydronic emitters, then room temperature can be maintained, but floor temperature exceeds maximum limits causing damage to floor materials
Solution Approach 1:
The system applies periodic pulsing action to the water flow through hydronic emitters, switching between on and off states in cycles. This periodic action allows the floor to cool between heating pulses, preventing overheating while still achieving the desired room temperature over time. The duty cycle is adjusted based on floor temperature feedback.
2Stability of the object's composition
If low flow rate is used in underfloor heating systems, then circuit balance is achieved, but time to raise room temperature becomes excessive
Solution Approach 1:
By pulsing the water flow at higher rates during on-cycles rather than maintaining a constant low flow, the system delivers more thermal energy per unit time when heating is active. This reduces the overall heating time while still achieving circuit balance through the periodic nature of the flow delivery.
Solution Approach 2:
The system performs preliminary heating action by delivering concentrated thermal energy in pulses before the full heating effect is needed, allowing the thermal mass of the floor and room to carry the temperature forward during off-cycles, reducing total heating time.
3Loss of energy
If room temperature is lowered overnight for energy savings, then energy consumption is reduced, but time to restore temperature becomes too long
Solution Approach 1:
The pulsing mechanism enables rapid temperature restoration by delivering concentrated heating pulses that quickly raise the room temperature from setback levels. The periodic on/off cycles allow for aggressive heating when needed while maintaining energy efficiency during maintenance phases.
Solution Approach 2:
The system dynamically adjusts the pulsing duty cycle and duration based on real-time temperature feedback. During temperature recovery from setback, the system increases the on-time proportion to accelerate heating, then transitions to maintenance mode with lower duty cycles to conserve energy.
4Productivity
If higher flow temperature is used in underfloor heating, then heating efficiency improves, but floor temperature exceeds maximum limits
Solution Approach 1:
The system uses periodic pulsing to deliver high-temperature water in controlled intervals, allowing the floor to dissipate heat between pulses. This maintains high heating efficiency during on-cycles while preventing floor temperature from exceeding maximum limits through the cooling effect of off-cycles.
Solution Approach 2:
The system applies preliminary heating with high-temperature water pulses to quickly establish thermal gradients, then relies on the thermal mass and conductive heat transfer to distribute warmth without requiring continuous high-temperature flow that would overheat the floor surface.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces the time to reach desired room temperatures while preventing floor overheating, enhancing comfort and safety by maintaining lower floor temperatures and allowing for multiple zone temperature control.
Implementation Method 1
heated water fills the circuit
Implementation Method 2
water flow through a hydronic emitter (circuit) heating the environmental entity
Data Source
AI summary
An underfloor heating (UFH) system limits the floor temperature of an environmental entity (for example, a room) by pulsing (pulse modulating) the flow rate through a hydronic emitter (circuit) heating the environmental entity. Once the heated water fills the circuit during time interval Ton, the flow is stopped for a fixed time Toff before allowing the cycle to repeat until a target temperature is reached. The ratio of flow/no flow (Ton/Toff) may be a proportional lower floor temperature compared to a traditional circuit supporting a constant water flow. The UFH system may heat a plurality of rooms, each having different floor temperature limitations. The floor temperatures may be limited differently by pulsing the hydronic emitters (circuits) rooms differently.