Air Source Heat Pump (ASHP) Hacks & Mods

[Geo NR Gee]

Now, what if I used it in conjunction with the GSHP? I see that they are somehow pulling heat from the gshp indoor unit for the house's hot water tank. Now I am going to have to research how to hook that up.

[Geo NR Gee]

Originally Posted by sparkchaser

Btw how long and what size tubing is the part that goes into the hw tank?

The tubing is looped. Its about 16-18 ft. or total 32 to 36 ft. long. Its looks like it is a 1/4 or smaller. I will be taking it apart as it was kinked when it was delivered.

What is the fitting in this picture? Is it for the schrader valve?

[sparkchaser]

About the picture: yes, that is the schrader valve for servicing the refrigerant. Larger systems will have two- one low pressure, one high. Small systems like this one or the one I'm going to hack, usually don't even have one. The service connection is crimped off and soldered shut. On those ones, you can install a bolt-on clamp/piercing style, or solder-on style service ports. Just don't forget to remove the schrader valve core with a tire valve stem core remover tool before soldering!

[sparkchaser]

Oh, and thanks for answering my question about the length/size too!

[Acuario]

Originally Posted by AC_Hacker

Yeah,

I'd like to know more detail on how you went about using the TXV, that's one of the big hurdles in converting an air conditioner into a heat source.

Also, does the unit you're using have a single speed compressor? Single speed fan?

If it is multi-speed, did you have to do any mods to make it work for you?

I'd like to see some details on the radiators that you are using.

The usual radiators that are available in the US assume pretty high feed temperatures, like 160F to 180F.

-AC_Hacker

Sorry for the delay in replying!
The TXV, well, humm, nothing special - I cut out the capillary, modified the routing of the tubing and just brazed it in place - that was about it! When I get a chance I'll play about with it a bit but at the moment it's all working super fine!

The fan is single speed - there is a pressure sensor that cuts out the fan when the pressure drops down. The compressor is single speed.

Details of the radiators are here: http://www.baxi.es/docs/sp_cataleg/h9.pdf
It's in Spanish but I'm sure you'll get the relevant parameters. They are aluminium and you can make them up to whatever size you want.

That's about it other than to say it's still working brilliantly and I still haven't used the oil boiler!

Nigel

[AC_Hacker]

Originally Posted by Acuario

Details of the radiators are here: http://www.baxi.es/docs/sp_cataleg/h9.pdf
It's in Spanish but I'm sure you'll get the relevant parameters. They are aluminium and you can make them up to whatever size you want.

Nigel,

Those are interesting looking radiators, what do you calculate the area (frontal area) is of those radiators is?

Also, what is the rated heat output from your compressor?

Do you know what the water temperature out from your heat pump is?

These would all be very interesting to know.

Did you ever mention where your location is in Spain? I'd like to find out what the Heating Degree Days is calculated to be in your area. I can find that information if I know the name of the nearest town...

Thanks,

-AC_Hacker

P.S.: Thanks for the information you have shared with us, I know it's very useful to our readers, even if we never hear from them...

[Acuario]

Hi,

I live near Tortosa, a city in the north east of Spain, close to the Mediterranean. The temperature rarely falls below 5C.

The radiators are sold per element and you can bolt as many elements together as you like. Each element is 8cm wide. There are various heights.

For example in the main bedroom which is about 15 sq metres I have 1 x 10 element x 70 cm high radiator, in the lounge/kitchen which is 50 sq metres I have 3 x 9 element x 70 cm high radiators. All the radiators have TRV's fitted.

The temperature of the water leaving the buffer tank is approximately 45 degrees c and the house temperature is a fairly stable 21 degrees c.

The compressor is a Mitsubishi RM5526GNE4. From what little information I have been able to find out it is rated at 1.9Kw in and has a heating capacity of 6.1Kw.

I am heating about 170 sq metres of house in total. The total number of elements (mainly 70cm ones) is 108.

Hope all this is of interest!

Nigel

[AC_Hacker]

Thanks, Nigel...

This is very useful information for anyone who may be considering something similar (like me).

-AC_Hacker

[Acuario]

No problem, if you want to know anything else then let me know.

All I would say is if it's something you're considering then stop considering and do it! Even if the results aren't quite what you expect the learning experience is fantastic; don't aim for perfection from the start - you can always revise/rework/try something else..

I don't know if I've just struck lucky with what I've done and how I've done it - I just did what seemed logical to do and so far it's working way beyond my wildest dreams.

I knew next to nothing before starting and I wouldn't profess to knowing a great deal more now but it's certainly been fun and I don't intend to stop yet...

Nigel

[AC_Hacker]

Originally Posted by Acuario

I knew next to nothing before starting and I wouldn't profess to knowing a great deal more now but it's certainly been fun and I don't intend to stop yet...

Nigel, I think you are have become an efficiency monster, and are having far too much fun!

Thanks for sharing your work with us, and I am looking forward to the next chapter...


-AC_Hacker

P.S.: By the way, I just checked out your heating degree days, and your annual HDD is 1,946, which is pretty mild compared to mine, which is 4,500. Lucky guy!

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