Most of China exporting industrial heat pumps are not direct-heating type; they are heating over water circulations between heat pumps and buffer tanks. It’s not a good solution for water heating because of 3 major insoluble problems:

• Water temperature in tanks fluctuate widely. Not comfortable to users. In a circulating-heating type heat pump system, cold water goes into tanks first. Heat pumps rise the water temperature through the circulations between heat pumps and tanks. At the beginning water temperature is low and with the running of heat pumps it goes up. So users need a pretty long waiting. What’s more, when hot water consumption peak time, water level in tank will drop quickly. The supplement water to the tank will make a mixture with existing hot water so it’s not comfortable to users.
• Water temperature of output hot water is restricted. Normally the max water temp that this kind of heat pumps can reach is 55℃. Exceeding 55℃ may cause troubles because the inner pressure will rise too much in such a system.
• Serious scaling affects efficiency. The structure of heat exchangers for circulating-heating type heat pumps is easy to scale and hard to clean. With the days of running, scaling will be more and more serious and the efficiency will be worse.

Advantages of direct-heating type heat pumps:

• Higher efficiency and adapt cold climates. COP reaches 4.5 or higher; Heat pumps can work regularly in ambient air temp of lower than 0℃.
• More simple installation. They don’t need buffer tanks. The cost of installation drops.
• Intelligent control and convenient operation. Direct-heating type heat pumps use microcomputer control system. Once you set it up, the system will running automatically according to your set and you don’t need arrange anybody on guard.
• Multiple control modes. Different customers have different requirements of water heating. For example, auto mode suit hotel, restaurant customers; timing mode suit school, factory customers.
• Memory function: power-down recovery. If the power is shut off, then turn on again, the working conditions of the machine will be same as before. So don’t need to reset.
• Centralized control. If you have a very big heating project, don’t worry how big should the heat pump be. You just need to install a number of small heat pumps and make centralized control to all of them. It’s a flexible and convenient solution for big projects.

A standard exclusive retail store of Wave heat pumps. With the area of 200 m² and interior decoration budget of 65 thousand US dollars. Have a look at the design sketches.

exterior appearance

reception counter

exhibition area

experience area of floor heating by heat pumps

meeting area

meeting area

top view

top view

How big should a water tank be for a household heat pump?

1. Normally, 40~50 liters of hot water is required for a person’s shower. Of course this number can be adjusted according to the shower customs of users.
2. Should there’re more than 1 washroom in your house, suggest adding 50~100 liters of water tank volume considering more than one shower are taken at the same time.
3. Should there’re bathes in your house, suggest adding 50~100 liters of water tank volume, too.

For instance, household heat pump for one family with 3 persons:

If one washroom, no bath, 150 liters tank will be OK; if 2 washrooms, no bath, 200 liters tank; if 2 washrooms, one of which has a bath, 300 liters tank will be good.

What is an ideal heat pump like?—-”Heat Pump Markets” magazine having an interview with Stanley Zhao, the sales manager of Wave Heat Energy Equipment Limited (China).

“Heat Pump Markets” Magazine (“H” for below): As we know, in recent years the markets of domestic heat pumps (also called residential heat pumps, household heat pumps) are developing fast. Is that true?

Stanley Zhao (“S” for below): Yes, that’s true, the developing even exceeded our expectation. If a heat pump manufacturer claims that they got an annual growing rate of 50%, it’s just an average level. Some manufacturers doubled their turnover in the past year of 2011 and Wave Heat Pump is one of them. One appearance you can see easily is that heat pump exclusive shops are opened in many county towns. We can’t imagine it a couple of years ago.

H: Then what’s the service conditions of those heat pumps that have been installed?

S: To be frankly, not ideal. Based on an investigation, 50% heat pumps with more than 2.5 years working period are already out of service.

H: That much?

S: Yeah, and it’s not acceptable. It means too many low-end products on our markets.

H: Could you tell something why so short lifespans for those heat pumps?

S: Two main reasons. The first is about materials and parts. Due to the fact heat pump industry is branched from air conditioner industry, many small factories just use materials and parts of air conditioners into heat pumps. However, the nature and the working conditions of the two products are not same. Heat pumps are often used to heat waters so they must be used to the high temperature working conditions. For instance, compressors should be different with those in air conditions, or the lifespan will be shortened much. Not only the compressor, all the other parts and the structure of heat pumps should fit the features of heat pumps.

H: That’s correct. I know some aircon part factories are producing heat pumps. And what’s the second reason?

S: Secondly, the structure of many heat pumps are not designed correctly. I can foresee they are just transitional products and will be obsoleted in some years. For example,  the majority of split type domestic heat pumps use “heat-exchanger-in-tank” design. This kind of heat pumps will have below troubles: 1) Low heat exchange rate, so the discharge temp of compressor will be high; 2) Scale formation on the in-tank heat exchanger is easy and the heat exchange rate continues to drop; 3) Chloridion in tap water will corrode the in-tank heat exchanger; 4) Hard to clean. When new installation maybe it’s good to heat water. But after some days of running the performance could drop by a big margin.

H: Then what’s the solution?

S: The thoroughly solution is to use another type of heat pumps. We call them “dynamically heating” heat pumps. We remove heat exchangers in tanks and the heating is done in main units. We add a built-in tank to circulate water between tanks and main units.

H: Is this range called “DO”series?

S: Yes. We have been producing this series for 8 years. With a lot of improvements made. the series is pretty mature now. We believe dynamically heating domestic heat pumps are the solution to all the disadvantage of other domestic heat pump products.

H: Thank you Stanley. Our magazine team look forward to more news from your company.

S: Sure. Thank you.

(Air source, split type) heat pump water heater installation. 37 photos.

It’s a static heating type domestic heat pump water heater (heat exchangers in tank). If dynamic heating type, more simple–no gas pipe job. Just connecting water pipes is OK.

1. packaged heat pump and water tank are ready

2.tools are ready

3.water tank unpacking

4.heat pump unpacking

5. accessories

6. gas pipes

7. elbow, adhensive tape, ribbon, release valve, T-piece, female elbow

8. ball valve, check valve, T-filter, XPAP-joint

9. drain pipe

10. XPAP water pipe

11. tie gas pipe and thermostat wire toghther

12. separated at the terminal of tied gas pipes for the convenience of installation

13. thicker is gas inlet, thinner is gas outlet

14. installation of tank seats

15. all the joints shall be coated by adhensive tapes to avoid water leakage

16. install release valve at hot water outlet. screw tight

17. release valve downward, connect XPAP-joint

18. install check valve at cold water inlet on tank. Note the direction of arrow is to the tank

19. install XPAP-joint at cold wate inlet, too

20. coat the connector of water pipe with adhensive tape then connect with XPAP-joint

21. connect water pipes, including cold water pipe and hot water pipe

22. fix frames for heat pump on the wall

23. drill

24. fix the frame

25. put heat pump onto the frames

26. fix heat pump with screws

27. insert thermostat into tank. screw tight

28. joint wires of thermostat

29. joint control panel with heat pump

30. power connection. must make earth connection.

31. joint gas pipes. screw properly tight

32. XPAP water pipe (red) connect tank and indoor water pipe (grey)

33. turn on tap, and fill tank with water. suggest open the release valve for the inner pressure is big

34. install drain pipe for condensate water

35. gas system evacuation

36. press on/off key on the control panel to turn on the water heater

37. installation completed

"Wave" swimming pool heat pumps installed

Selecting “Wave” swimming pool heat pumps as your pool heaters is a good idea. The reasons are:

1.Unlike conventional pool heaters, swimming pool heat pumps are not energy transformation devices; they are energy diversion devices. Following the principle of reverse Carnot cycle, swimming pool heater pumps deliver heat energy from ambient air to pool water. The input electricity to swimming pool heat pumps are just to drive compressors and some other parts, not to make heat. So swimming pool heat pumps are hugh efficient heaters: 1 electricity consumption can bring 5 or more heat energy. With same output heat energy,by using Wave swimming pool heat pumps you can save at least 75% than electric water heaters; 50% than fuil oil or gas boilers (geysers); 60% than solar heaters. Just count how much money you can save in one year!

swimming pool heated by "Wave" heat pumps

2.Big capacities and small space required for the units. By modular installation which control many units, we can make very big swimming pool heat pump projects. What’s more, the installation are more convenient than other pool heaters.

3.Long lifespans. Normally “Wave” swimmin pool heat pumps can service 15~20 years or more.

4.High safety. So far heat pumps are definitely the most safe water heaters compared with electric heaters, fuil oil heaters, gas heaters and sloar heaters. They don’t have potential dangers of electric shock, burning, gas leakage, thunder shock, etc. Swimming pools are often public places, so the security is more important.

5.Eco-friendly. No harmful gas discharging compared with fuil oil heaters and gas heaters. Swimming pool heat pumps are totally Eco-friendly pool heaters.

natatorium equipped with "Wave" swimming pool heat pumps

6.Superior control system. “Wave” swimming pool heat pumps applied central control systems. They are running automatically and don’t need anyone on guard at all.

7.Reduce humidity and supply fresh air. It’s common that there are high humidities and bad air in natatoriums or at swimming pools. Some models of “Wave” swimming pool heat pumps can control humidity and supply fresh air at the same time when they are heating water. Conventional pool heaters can’t do these.

8.”Wave” swimming pool heat pumps use high-end parts, many of which are No.1 brands globally. For examples, Copland compressors, Grundfos water pumps, Emerson valves, etc. Not only those, “Wave” swimming pool heat pumps use copper foil evaporators instead of aluminium. Almost all the other heat pumps use the latter (aluminium), you know.

heat pump hot zones globally

Biggest heat pump markets in Oceania:

• heat pump Australia
• heat pump New Zealand

Biggest heat pump markets in North America:

• heat pump America

Biggest heat pump Markets in South America:

• heat pump Chile

Biggest heat pump markets in Europe:

• heat pump Germany
• heat pump France

Biggest heat pump markets in Africa:

• heat pump South Africa

Biggest heat pump markets in Asia:

• heat pump China

reciprocal links wanted

Our website (http://www.waveheatpump.com/) are now seeking partners of reciprocal link (friend link) exchanging. The relevant sites can be with below contents:

• heat pump products and parts: compressors, heat exchangers, evaporators, valves, etc
• heat pump technology
• geothermal
• renewable energy, sustainable energy, clean energy (e.g. solar, wind, bio…)
• HVAC
• refrigeration
• water heater, boiler, geyser, chiller
• swimming pool, spa, sauna

Please contact us if your company are in these fields and are looking for reciprocal links as well.

Commercial heat pumps, also called industrial heat pumps, usually installed on big buildings for central air conditioning or water-heating. In recent years, more and more commercial heat pumps are replacing conventional water heaters, e.g. boilers, electric water heaters, geysers, gas water heaters at hotels, restaurants, factories, schools, etc.

(In this article, we only talk about air-water heat pumps, which are the most popular and the fastest developing heat pumps presently.)

The classification of commercial heat pumps are not complicated: generally there’re 2 kinds of them: circulation-heating type and instant-heating type (direct-heating type). Engineering for them are different, too.

working principle of circulation-heating type commercial heat pump. water temp is raised gradually.

Circulation-heating type commercial heat pumps raise water temperatures several degrees (e.g. 3~5 ℃ in one circulation ). It will need many circulations for this type to complete water heating. And their main engineering features are:

1. A buffer tank for water circulating with heat pumps is necessary for each project;
2. Cold water goes into the buffer tank (not goes into heat pumps);
3. A circulation water pump on the pipe between the buffer tank and heat pumps is necessary.

working principle of instant-heating (direct-heating) type commercial heat pumps. water temp are raised to terminal once.

Instant-heating type (direct-heating type) commercial heat pumps raise water temperatures to terminal degrees directly. That means, cold water goes into the unit and comes out with the completed degrees (e.g. 60℃). Their main engineering features are:

1. Buffer tanks are not required, only storage tanks will be enough;
2. Cold water goes into heat pumps;
3. Circulation water pumps are not needed.

Instant-heating type (direct-heating type) is more advanced tech than circulation heating type. Industrial heat pumps of this type have many advantages. We will talk about this in another post.

During selling domestic heat pumps to foreign countries, we find out that quite a lot customers prefer to remain their existing water heaters (geysers). They want to update their existing water heaters with heat pumps instead of uninstall them.

It’s not a simple question. We should start with the analysis of the tank of your existing water heater (geyser).

First of all, you should confirm whether the tank of your water heater (geyser) is pressure-bearing or not? Simply speaking, pressure-bearing tanks output hot water by the pressure of tap water. They don’t need extra other force (like water pumps, force of gravity). On the contrary, non-pressure-bearing tanks need extra force to output the hot water. If the force is not from a water pump, then the tank should be installed higher than the shower place (actually use the force of gravity).

Do as below if your tank is pressure-bearing (most of household electric water heaters are this type). If  non-pressure-bearing, the updating are more simple. Just buy our commercial models with small capacities for updating, like CO-10.

Basically there’re 2 updating solutions according to different types of existing tanks of water heaters (geysers): Solution A. don’t put heat exchangers into existing tanks; and Solution B. put heat exchangers into existing tanks.

[Steps for Solution A]

a typical electric water heater (geyser) that should be updated with heat pumps by Solution A.

If you find it’s difficult to open your (water heater) geyser’s tank, all you can do are some plumbing work and making water pipe connections, then you should choose solution A.

1) Heat pump type selection. You should choose “dynamic heating type” (water-circulating type) domestic heat pumps. Dynamic heating type heat pumps don’t require heat exchangers in tanks. They do the heat exchange in the machine.This kind of heat pumps are connected to tanks with water pipes for installation only.

2) Make necessary modifications on the existing tanks of electric water heaters. The most important change to the existing tanks is to insert a thermostat (water temp sensor) into each tank to be updated. Otherwise, control systems of heat pumps will not be able to detect water temp in tanks.

[Steps for Solution B.]

a typical water heater (geyser) tank that should be updated with heat pumps by Solution B. Notice the central part.

If you find that your existing water heater (geyser) tank can be opened and recovered, then it’s possible to insert the heat exchanger (refrigerant/gas coils), then you should choose Solution B. As far as we know, some oil geysers use this kind of tanks.

heat exchanger to be inserted into water heater (geyser) tank in Solution B.

1) Heat pump selection. You should choose “static heating type” (refrigerant-circulating type) heat pumps.Static heating type heat pumps require heat exchangers (refrigerant /gas coils) in tanks to make heat exchanging.

2) Make necessary modifications on the existing tanks of electric water heaters. The most important change to the existing tanks is to insert a thermostat (water temp sensor) into each tank to be updated. Otherwise, control systems of heat pumps will not be able to detect water temp in tanks. (this step is same to Solution A)

Above are the most important 2 points to make the update for each solution. Of course, some other details should be considered according to the real electric water heaters (geysers) in use. If there are such update requirements on your markets and you are interested in distributing residential heat pumps, why not contact us –Wave Heat Pump for more information?

>>>Author: Stanley Zhao (Manager of Overseas Marketing Dept, Wave Heat Pump)<<<