How to convert a single-cooling air conditioner into a heating-and-cooling air conditioner

In simple terms, all you need to do is upgrade the configuration of the single-cool air conditioner to that of a dual-cool and heating air conditioner. Generally speaking, the cost of the modification is not low. 

1. First of all, re-administering fluoride is necessary (this is certain). 

2. Add "four-way valves and one-way valves" to the outdoor unit's condenser. 

3. If necessary, an additional "auxiliary electric heating" system should be installed in the indoor unit (the effect will be even better). 

4. The original single-cooling electronic control board should be replaced with a "thermostatic electronic control board". To reduce costs, an "adapted board" can be used. 

5. The indoor and outdoor connection lines also need to be modified (the modifications will be made according to the actual situation; the four-way valve needs to be powered on). 

6. When modifying, it must be done without the mindset of eliminating all risks. Especially for the auxiliary electric heating part, one must take into account the matching of power consumption and power supply lines, and "even more importantly", consider the insulation issue during fixation.