Make hot water with ... air conditioner

Take advantage of the heat source discharged from the air conditioner (air conditioner) to . heat the water in the hot and cold bath is a solution to save electricity, contributing to environmental protection.

That is the result of the study of Le Van Dung, a senior in the Faculty of Mechanical Engineering, Ho Chi Minh City University of Technical Education.

Once the hot air flow is received from the air conditioner of the air conditioner, it is thought in the beginning to take advantage of this heat source to heat the water, while 'reducing the load' for the heating element of the heater, cold.

Twice save

After nearly 5 months of tinkering, with the help of his brother who is an air conditioner repairman, Dung has launched a machine system that can adjust the temperature by programming, cut off the temperature . Accordingly, the gas from the tank Compression (up to 900 at this time) will go through the cooling section to lower the temperature to about 300.

Thanks to this difference, low pressure will convert the gas to a bit cold. Instead of the heat source from the hot tank going directly to the cooling unit, Dung connected this heat source duct through the duct system to the water tank to heat it, before returning it to the cooling unit.

Le Van Dung introduced the hot water heating mechanism from the air conditioner of air conditioner.Photo: T. Ngoc

In this way, 1-hp air conditioner to boil 20 liter water bottles on 700C takes more than 40 minutes. If using 2-hp air conditioner, this time is shortened to half.

Thanks to being led through cold water bottles to heat up, a large part of the heat has been cooled down in the righteous water. Therefore, the cooling part of the machine will operate lighter, the heat will be released less. Machines operating at low power will consume less energy.

Associate Prof. Dr. Le Chi Hiep, Chairman of the Department of Refrigeration Technology, Ho Chi Minh City University of Technology, commented: this is a good idea, in principle, fully feasible. If done correctly, we take advantage of the excess energy and reduce electricity consumption for the operation of air conditioning. However, when making hot water, it is necessary to have cold replenishment measures in time, otherwise this hot water heater may cause harm to the air conditioner.

Can be large scale application

The system also has a neutral water bottle (helps neutralize boiled and unburnt water to adjust for each use purpose). When the air conditioner does not work, the neutral tank acts as an independent water heater. When the air conditioner operates, the neutralizer will be cut at the neutral.

In addition, a water supply system for boilers and water storage after heating is also designed by Dung so that when heated to the required temperature, the system automatically discharges into the heat sink and supplies new cold water. .

The whole system is managed by industrial PLC programming with relays, temperature control buttons and numerical and letter indicators that make it easy to identify. The price of a control system is about VND 6 million (not including public, profit).

This system can control a large factory with many industrial air conditioners. In an office or a factory, connecting these air-conditioners to a large water tank can be used for many purposes: for living (bathing, washing); cleaning bottles, product packaging, product preliminary processing .

Hotels with many air-conditioners can take advantage of this energy to boil water without having to use each room for a hot, cold machine. This system is very effective in families using two or more air conditioners (benefit of initial investment costs).

In particular, this system is of great significance when taking advantage of the excess energy to heat, without having to use another source of energy, helping to save energy and reduce environmental pollution.