Heat Pump Fan Grill Spacing to Prevent Ice Bridging
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Solution Overview
Problem
Heat pumps operating in freezing conditions experience ice buildup and ice-bridging in the fan/orifice ring system, leading to reduced airflow, noise, and decreased heating efficiency, as traditional discharge grills allow ice formation due to their spacing design.
Innovation Solution
A housing design for outdoor HVAC units with a grill having more closely spaced members than the fan/orifice ring clearance, combined with relief air vents, to reduce ice buildup and maintain airflow, while adhering to industry safety standards.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional discharge grills with larger spacing are used, then airflow is improved, but ice buildup and ice-bridging occur in the fan/orifice ring system
Solution Approach 1:
The patent changes the critical parameter of grill member spacing from traditional larger spacing to a smaller spacing (less than the running clearance between fan blades and orifice ring). This parameter change causes ice to form on the grill members themselves rather than bridging across the fan/orifice ring clearance, thereby preventing harmful ice buildup while maintaining adequate airflow through the housing.
2Object-affected harmful factors
If grill members are spaced closer together, then ice buildup is reduced, but airflow may be restricted
Solution Approach 1:
The patent identifies and changes the spacing parameter of grill members to be less than the running clearance between fan blades and orifice ring. This specific parameter change creates an optimal balance where ice forms on the grill members rather than blocking the fan/orifice ring path, and the housing design with side panel openings and relief air vents ensures adequate airflow is maintained.
3Reliability
If ice buildup occurs in the fan system, then operation continues but noise increases due to ice-bridging
Solution Approach 1:
The patent converts the harmful effect of ice formation by changing where the ice forms. Instead of ice forming in the fan/orifice ring clearance causing noise and potential damage, the smaller grill member spacing causes ice to form on the grill members themselves. This converts a harmful ice buildup location into a benign one that does not interfere with fan operation or generate noise.
4Reliability
If ice buildup occurs, then airflow is reduced causing reduced output and heating efficiency
Solution Approach 1:
The patent converts the harmful effect of ice formation by changing where the ice forms. Instead of ice forming in the fan/orifice ring clearance causing noise and potential damage, the smaller grill member spacing causes ice to form on the grill members themselves. This converts a harmful ice buildup location into a benign one that does not interfere with fan operation or generate noise.
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
The solution effectively mitigates ice buildup and noise, ensuring continued operation and maintaining heating efficiency by allowing proper airflow through the unit, even under icy conditions.
Implementation Method 1
Heat pumps sometimes operate in conditions of freezing precipitation such as freezing rain, snow, sleet, hail, and the like
Implementation Method 2
Each side panel comprises openings enabling airflow into the housing
Data Source
AI summary
A protective housing is provided for a heating, ventilation, and air conditioning (HVAC) unit having a fan therein. The fan comprises a plurality of blades, each blade having a proximal and distal end. The housing comprises a plurality of side panels, each side panel comprising openings enabling airflow into the housing. The housing further comprises an access panel that is coupled between two of the plurality of side panels wherein the access panel and the plurality of side panels form an enclosure. An orifice ring is mounted within the housing, wherein a running clearance between the distal end of the fan blades and the orifice ring has a first spacing. A cover fastens atop the enclosure, the cover comprising a grill having a plurality of grill members, wherein the grill members are separated by a second spacing, the second spacing being smaller than the first spacing.