Heat Pump Water Heater

[gachu26]

baad

[dos541]

I have a electric hot water heater and wean it turns on you can hear water boiling in it and it is loud boiling wean it first starts then it quiets down a bit is that normal and i ran hot water out of the sink for a while and all the air should be out of the heater i tried to turn down the water temp but that dosent help

[waterwart]

Okay you have saved some electricity to make hot water. But I would like to see something you built that would save money from cooking food. That would be interesting. Maybe....like an electric stove that doesn't use a lot of electricity. Nice videos by the way man. Keep up the good work.

[zolapalooza]

Hmm - nice project if you have the spare time but this could be done a bit quicker if you can get hold of a water source heat pump and make some mods or getting hold of a pool heater which is essentially the same thing. Here in the gulf south of the U.S. there is a company called Florida Heat Pump (FHP) that makes very good water sourced heat pumps.

[MrEnergyCzar]

I got a heat pump water heater for my solar home and it's awesome....I can't believe you built your own....nice job.

[slamdvw]

Built one similar for heating an above ground pool. Worked like a charm. Never thought about using a coiled condenser coil though, good idea. Subscribed! Love the videos.

[acnfanmanin]

That is an awsome idea!

[g60scuzz]

Excellent setup thanks for sharing!

[airconguy1]

I thought heat pumps only produced heat around your body temperature, which is why the air never feels hot coming out!

[tesla500]

@airconguy1 That's typical of central heating heat pumps, the cooler the air, the higher the efficiency. You can produce heat at much higher temperatures, the efficiency is just lower. For example, the COP (heat out / power in) of a central heating heat pump may be 3 to 4, this water heater has a COP of about 2.

[67tr876]

hmm am not sure but did i tell you am making a chiller for the water now ? i might need your help.

[Carltech100]

Very nice demo, thank you. I have been putting one of these together on paper before building it. I like the idea of the "pipe in pipe". Never seen it before and am having difficulty in locating a supplier. Could you supply any info? I am in Cape Town but should be able to trace a local supplier from an overseas one. Also, is the piping/tubing made of copper? I have searched under double walled piping and jacketed piping.

[tesla500]

@Carltech100 Thanks!

I made the pipe-in-pipe myself, I just inserted a piece of 3/8" copper tube through a 3/4" IPEX flexible plumbing pipe. I actually did this after coiling both, by "screwing" the copper pipe into the IPEX, but it could be done while straightened out too. The total coiled length is about 7m, which seems adequate for a 10,000BTU/h compressor.

[Carltech100]

@tesla500 Thanks, I will try this.

[partypalooza5]

Where did you get the other parts to make this system? (The sight glasses, expansion valve, etc)

[tesla500]

@partypalooza5

I got those from an online store called rparts. You could likely get them from your local refrigeration supplier too.

[wtfwellington]

I've been thinking of making this all day! haha. 

have you thought of adding a safety-condenser for outside, when the heat of the water makes the high side pressure too high? like have it controlled by a duty high pressure switch and solenoid that would be on the beginning of the safety condenser, normally closed.

I was just thinking before I saw this video that if this thing was actually made there would have to be a generous set of safeties to lengthen the life of the equipment.

[gavincurtis]

Just out of curiosity, is a heat pump design more efficient at heating water vs conventional submerged electric heating elements?

Thanks.

[tesla500]

Yes, it's about 2 to 3 times as efficient as a heating element, depending on the outside air temperature.

[gavincurtis]

Very nice!

[partypalooza5]

I may have to build myself a system like this. Just got to find the parts now..

[Aussie50]

Wow! really cool system!, I'm impressed!

[tesla500]

Thanks!

I had this unit mostly complete about 2 years ago, but it just sat on my work bench taking up space. Recently the gas water tank blew, and I replaced it with an electric one, and got the motivation to complete this heat pump. It should be running in the next couple of days. I'll have a video of the complete system soon.

[partypalooza5]

Really nice design! As far as the R290 is concerned, did you use BBQ grade or did you get the type designed to be a refrigerant? And if it is the refrigerant type is it still flammable?

[tesla500]

Thanks!

I used BBQ grade. I probably should have gotten the proper refrigerant grade, but you can't beat the availability of BBQ grade.

Both grades are pretty much equally flammable. Since the entire refrigeration system is outside in this case, I'm not too worried, any leaks would quickly dissipate instead of possibly pooling indoors. I also used sealed relays so there's no source of ignition.

[legogunsmith]

why not just on demand electric hot water heater it would be more efficient ? sight glass on suction side it would be normal to see a mix depending on your evap function

[TehMG]

On demand water heaters just save energy by eliminating standby heat losses.

A heat pump system actually produces more heating power than the power required to run the system.

For example, an electric heater with a 3kW element would produce 3kW of heat, while a heat pump system could produce 3kW of heat while only consuming 1kW of electricity.

Nothing is more efficient than a heat pump system. The disadvantage is heat pumps do not perform well in very cold climates.