Heat recovery from fridge compressors

[Tullyvernon]

Don't want a pressurised system to make it work best. Our heat recovery has its own thermally insulated tank that transfers to the Cotswold on demand so water entering the Cotswold is at say 55 deg so the heater only has to add another 20 deg or so rather than heating stone cold water off the mains at say 10 deg now or warming it another 70 degs. Easy to see the savings there when the heat would only be wasted otherwise
Should add that we are washing the plant x3 a day now

Correct, Cotswold or similar design water heaters are the best way to prevent heat loss and get the most from a HR system.

On average i count a 26 month return on investment on a correctly installed system

 

[William26]

Friend of mine recently installed the xchanger glycol system on 400 cows and is getting a quarterly cheque of 9k in RHI payments and his milk enters the tank at 3 degrees so tank compressor never running, he’s heating his hot water, space heating his workshop and even heating his washdown water [emoji23]

Makes an absolute mockery of the RHI scheme but its all above board and linked to inflation so seems a sure investment

He did say initial capital was quite large but with the way electric is going I’m sure it will payoff

Any news on how the system is running now?

 

[Triangle]

For monitor ing elec use i have a emporia unit off amazone does 16 circits works for single split or 3 phase total use and individual in graphs per second muinet day week year wish i had it before smart heat system all i know now is less compressors run more warter heater uses

 

[upnortheast]

For monitor ing elec use i have a emporia unit off amazone does 16 circits works for single split or 3 phase total use and individual in graphs per second muinet day week year wish i had it before smart heat system all i know now is less compressors run more warter heater uses

Good idea. Always amazes me, folk are prepared to spend £££££ on things like solar or heat recovery without get some idea of their current pattern of usage to access the viability of the project

 

[Grassman247]

For monitor ing elec use i have a emporia unit off amazone does 16 circits works for single split or 3 phase total use and individual in graphs per second muinet day week year wish i had it before smart heat system all i know now is less compressors run more warter heater uses

Are you saying the water heater is cheaper than having the compressors running longer?

 

[In the pit]

Good idea. Always amazes me, folk are prepared to spend £££££ on things like solar or heat recovery without get some idea of their current pattern of usage to access the viability of the project

Heat recovery of a compressor is basically money for nothing
Hot gas comes of bulk tank through a heat exchanger (water tank) and heats the water /and cools the gas before going back through the compressor to start the circuit again
I’ve had water to 60degrees which is then put into parlour or bulk tank boiler
What’s not to like???

 

[vantage]

Heat recovery of a compressor is basically money for nothing
Hot gas comes of bulk tank through a heat exchanger (water tank) and heats the water /and cools the gas before going back through the compressor to start the circuit again
I’ve had water to 60degrees which is then put into parlour or bulk tank boiler
What’s not to like???

So long as you’ve put it through an effective plate cooler first.

 

[In the pit]

System I saw used something like this

 

[upnortheast]

Heat recovery of a compressor is basically money for nothing
Hot gas comes of bulk tank through a heat exchanger (water tank) and heats the water /and cools the gas before going back through the compressor to start the circuit again
I’ve had water to 60degrees which is then put into parlour or bulk tank boiler
What’s not to like???

Did the sums a number of times & the savings did not cover the capital cost quickly enough
When it came on the grants scheme 2 years ago then it was well worth doing

 

[In the pit]

Capital cost of couple thousand versus heating your water to 50/60 using electric

 

[Triangle]

In theory its the same as ground source /air source is supposed to be more efficient except its milk source im saying it is cheaper than a epement the less milk we have to cool our elec goes up slightly so when less milk i have tank set colder as its cheaper than not
On the otherhand runnig a icebank is expensive by the time you factor in running the chilled warter pump but happy milk buyer and flexibility /instant cooling is priceless honestly recommend the 150quid off amazone emporia monitor

 

[Farmer Keith]

Put a muller heat recovery in at the start of April and it’s knocked 15% off our daily electricity usage. Can’t complain at that. We’ve also got an abundance of spare hot water sitting at about 60°c if we could get it into the house we’d be laughing.

 

[upnortheast]

Capital cost of couple thousand versus heating your water to 50/60 using electric

For every 100 litres of water, to heat from 10C to 80C takes 8kw leccy
60C to 80C takes 3kw leccy
Difference 5 kwh @ 20p ?? £1 /100 litres

Limiting factor is how much water you can use. If you only use 100 litres alternate days to wash the tank then your saving is only 50p / day
Also should be saving on compressor running as the gas is returning cooler but more difficult to quantify. Need one of @Triangle emporia units to measure accuratly

 

[In the pit]

For every 100 litres of water, to heat from 10C to 80C takes 8kw leccy
60C to 80C takes 3kw leccy
Difference 5 kwh @ 20p ?? £1 /100 litres

Limiting factor is how much water you can use. If you only use 100 litres alternate days to wash the tank then your saving is only 50p / day
Also should be saving on compressor running as the gas is returning cooler but more difficult to quantify. Need one of @Triangle emporia units to measure accuratly

So 500 lts /day equates to £5 /day equates to being paid back in approx 400 days
We use water for bulk tank washer and for parlour circulation twice a day
How quick do you want your pay back to be

 

[upnortheast]

So 500 lts /day equates to £5 /day equates to being paid back in approx 400 days
We use water for bulk tank washer and for parlour circulation twice a day
How quick do you want your pay back to be

We dont need 500 litres hot water a day
In your case the jobs a no brainer
I come across folk who have spent big money on heat recovery but have not done any sums on the viability, apart from taking the salesman`s bullshite as gospel

 

[Bald n Grumpy]

Put a muller heat recovery in at the start of April and it’s knocked 15% off our daily electricity usage. Can’t complain at that. We’ve also got an abundance of spare hot water sitting at about 60°c if we could get it into the house we’d be laughing.

What sort of price was it?
Had the leccy bill this morning and didn't like it

 

[In the pit]

We dont need 500 litres hot water a day
In your case the jobs a no brainer
I come across folk who have spent big money on heat recovery but have not done any sums on the viability, apart from taking the salesman`s bullshite as gospel

You can use hot water for anything
Parlour ,bulk tank,calf milk powder general washing and cleaning

 

[O'Reilly]

For every 100 litres of water, to heat from 10C to 80C takes 8kw leccy
60C to 80C takes 3kw leccy
Difference 5 kwh @ 20p ?? £1 /100 litres

Limiting factor is how much water you can use. If you only use 100 litres alternate days to wash the tank then your saving is only 50p / day
Also should be saving on compressor running as the gas is returning cooler but more difficult to quantify. Need one of @Triangle emporia units to measure accuratly

Be more than 20p now, some people on double that. But see your point.

 

[Farmer Keith]

What sort of price was it?
Had the leccy bill this morning and didn't like it

Off the top of my head £2900 with a 40% grant on it, saving 15kw a day give or take so will pay for itself in less than 2 years and when our electricity contract runs out will be saving significantly more.