Automotive compressor heat pump

[Phil K]

Howdy folks and gurus!
Could an automotive type compressor be used for a heat pump system?
I was looking at using one for an in floor system to heat a work shop.
The junk yards around here are full of cars,trucks and vans where you could choose any where from 1 to 4 ton units.
I do have lots of well water available and some 3 phase motors and VFDs kicking around.
We have lots of wind here and wind power is something I will want to add to this as well.
I could use the auto type control systems such as pressure switches and 12 volt clutch etc.
These are using 134a for refrigerant in the vehicle.
Is the 134a ok for this or would I have to chang to r410a or something?
I would have to use some type of liquid heat exchangers for both evap and condensor.
Will this type of compressor last or give a good service life?
Which compressor type might be the best as in ford dodge chev?
when I get the wind power up and going I plan to use a hydraulic pump and motor set up so the motor speed would always be changing, well I guess just like a car engine does!
Thanks ahead of time and sorry about all the dumb questions!

[Phil K]

A little help would have been nice
I am an electrician and a mechanic by trade.
I would have helped you in my field
Dont forget how inventions are made from so called crasy ideas
Thanks and bye!

[nike123]

Howdy folks and gurus!
Could an automotive type compressor be used for a heat pump system?

Yes

These are using 134a for refrigerant in the vehicle.
Is the 134a ok for this or would I have to chang to r410a or something?

Yes, 134A is good enough and you cannot change to R410A due to higher pressures of R410A

Will this type of compressor last or give a good service life?

That depend on state of used compressor. More harsher conditions are in the car then in intended use, so it should be good.


Do you know anything about refrigeration system dimensioning, since this task is pretty hard even for experienced refrigeration technicians, and not knowing basics and system components matching principles, could lead to many unsuccessful experiments?

[nh3wizard]

A little help would have been nice
I am an electrician and a mechanic by trade.
I would have helped you in my field
Dont forget how inventions are made from so called crasy ideas
Thanks and bye!

What an ARSSS!!!!

[Brian_UK]

A little help would have been nice
I am an electrician and a mechanic by trade.
I would have helped you in my field
Dont forget how inventions are made from so called crasy ideas
Thanks and bye!

Maybe no answers because no-one has one.

We tend to use things designed for purpose.

Nothing against inventions but perhaps you should try an inventors forum instead.

Why is it that people who don't get what they want immediately always behave like children?

[back2space]

The guy barely gave it 4 hours to wait for a response!!!

Patience is a virtue!

[SteinarN]

The guy barely gave it 4 hours to wait for a response!!!

Patience is a virtue!

Well, he actually waited nearly 3 days.

[SteinarN]

It is possible to use an automotive type compressor, but I doubt it is sensible. Automotive type compressors have a lousy efficience, a shaft seal making leaks more likely, difficult or impossible to check the oil level, originally filled with undesireable PAG oil to mention a few reasons.

If the original oil is thoroughly flushed out, displacement/capasity is determined, correct oil charge for the system is estimated, a suitable RPM (not over 2000) is selected, correct heat exchanger size and pipe sizes is calculated and correct installation procedures is followed, then it should probably work.

[Phil K]

Sorry guys
I thought after 3 days I was being ignored or looked at as some kind of crack pot.
I could see where lots of folks looked at it but did not reply.
I did give a lot of thought to the idea of electric power transmission from the wind mill but with long distance losses, batteries,inverters, etc. I have come to the conclusion that a direct coupled hydraulic system would work better.
I realise that this system could only put some heat under the slab but it should put 4 times as much as a straight heat resistance type and some heat is better than no heat!
On a day I want to use the shop a wood fire could make up the difference.
Since the compressor speed is totally dependant on wind speed it would be very hard to calculate any thing.
Just going to get more heat on a windy day!
How do you work out how much oil would be required?
Maybe I could mount the compressor directly to the wind mill and just run a line set from there to the shop.
would enough oil go up the tower to keep the compressor happy?
Is there some new kind of oil that replaces the pag oil that is better for the 134a?
Here in Canada we have a store that sells tube type heat exchangers for cooling hydraulics and look to have roughly the same amount of tubing as the car ones do but the tubes are in parrallel.
I was hoping I could play with a high pressure needle valve instead of the fixed orfice or thermal valve some cars use.
any thoughts or pros and cons?
Thanks again and I will behave now!

[Gary]

Sorry guys
I thought after 3 days I was being ignored or looked at as some kind of crack pot.
I could see where lots of folks looked at it but did not reply.

I suspect it is not so much that everyone is ignoring you, nor that they think you are a crackpot, but that nobody knows quite how to respond.

What you are proposing is building a complex system from the ground up, using non-standard components, while having no knowledge of how that system works, much less how to design or build it.

You might want to start with a more modest project. For example, taking a standard heat pump and substituting a wind driven automotive A/C compressor. That, in itself would be a major project involving a steep learning curve.

[Phil K]

Ok, I guess there is a challenge in this which is not all bad!
The hydraulic end of this from the windmill in to the motor I am comfortable with.
I do understand hydraulics fairly well and am ok with the calculations for them.
The refrigeration end of this I only have the training from auto and heavy duty mechanics.
These trades give you the basics but dont go far enough in depth to tell you why things are different sizes and various refrigerants are used.
It was a just find the leak, evacuate and charge what the label said and check for roughly 32 lbs on the low and 175 lbs on the high and kick it out the door.
What if I put this project another way?
How about I take the entire system out of a car.
Then rehook it all back up test bench style by turning the compressor with a 3 phase motor running from a VFD and throw the condenser and evaporator each into a barrel of water.
No I wouldnt leave this like this but would it work so far just for testing?

[Gary]

Why throw the condenser and evaporator into barrels of water?

[Phil K]

I think or hope that perhaps I could measure temperature rise and or fall from the barrels and compare that to electrical watts of the input of the motor that is driving the compressor.
This experiment would show me how the system that was using air as the heat moving medium in the car would perform in a liquid enviroment.
I may then get a rough idea of just how much of a gain I can hope to get over straight resistive heating.
Hopefully the end result could be 2 neat looking pipe and tube type of exchangers mounted on a wall with floor heat liquid in one and well water in the other replacing the barrels and car evap and condensors.

[Gary]

I would suggest starting with a complete automotive system, including the evaporator and condenser fans. Then change one variable at a time, the first being the means by which the compressor is driven. If/when you can make that work, then move on to the next variable.

[nike123]

You said that you have lots of well water and wind power. Why don't you use plain electric generator and electric heaters to heat floor if that is the case. In both cases (heat pump and electric heaters) you need well insulated space to satisfactory heat with floor heating.
Also you could use well water for direct cooling. Why you want to mess with complicated equipment when you could use energy in simpler way.

[Phil K]

Thanks
I know how to get 80% energy from electric or hydraulic but would like to pump some heat from the well water.
The easiest and cheapest compressor to find with a pulley on it is a automotive type!
A 2 mile trip to the junk yard gets me another one if something gets wrecked.
On a side note I have worked on generators most of my life as a professional and do have that trade ticket.
My other 3 tickets are light and heavy duty mechanic and electrician (master)
I am now retired and besides cutting grass and plowing snow am bored as hell,
A new word should be retiredasucide!
All I was looking for was some educated hints in this project for example how big and long to make a heat exchanger and which way to point each end up and down and where to put things to work the best.
I have another place in Alberta Canada which is all in floor heating but use natural gas condensating boilers as the heat source.
The infloor heat is by far the best and the water temp to the floor rarily has to go over 90*F
The efficiancy of these can actually get to 109% by reclaiming the heat from condensate.
Here in Pei I was hoping to create a hobby and harness some of this wind going past my back field.
I again say that I have started this thread off on the wrong foot and hope for a new start!

[Gary]

Sounds like an interesting project. Let us know when you get the components together and we'll help walk you through it.

[Phil K]

Thanks Gary!
Most of the donor vehicles are under 3 feet of snow now so it will be a while before I get going on this project.
My hopes of gathering things up ahead of time are slowly drifting away if you catch my drift!

[techguy]

HI Guys,

Sanyo Have already done it.
GHP system dual compressor heatpump driven by a Nissan engine running on either natural gas or LPG.

So yes it can be done if you have someway to control engine speed reletive to capacity. there is also the ability to produce hotwater as the engine will be water cooled and this heat can be reclaimed.

Install a second plate heat exchanger on the suction line with some form of bypass valves when the external ambient is very low use this heat exchanger as your primary heat source for the refrigerant then you have no defrost issues.



T

[Gary]

Automotive A/C's have a magnetic clutch in the drive shaft which engages/disengages according to suction pressure.