designing a heatpump

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02-01-2006, 12:40 PM
ianandkitty

designing a heatpump

Hi
Can anyone help me im making a ground source heat pump to do heating only in my home.
i need cond temps of 40-75 oC for heating and hot water
I have been looking at copeland scroll compressors
Looking around most heatpumps seem to run on r410a
but i dont think this can get the tempratures im looking for.
http://www.ecopeland.com/prodcat.cfm...ref=7&prod=528

but would i be better using r134a as i think this will reach the desired temp http://www.ecopeland.com/prodcat.cfm...f=8&prod=30692

But i must have a good c.o.p. r410a heatpumps seem to have a cop of around 3-5 but i cant find any heatpumps using r134a

i know that my ground loop water through my evap will be at a constant 4-8 oC

so would that suggest that 410a is a lot more efficient than 134a??
any help please before i buy an expensive compressor thats no good...
31-03-2006, 02:07 AM
Lc_shi

Re: designing a heatpump

I think you can use normal condenser for heating and desuperheating for hot water. R134a's cop is a little higher than r410a ,but with lower discharge temp. r410a's compressor and piping system should be more expensive. Detail compare the cost before you decide to use r410a or r134a. there's lot things to consider. If you need help,let me know your requirement and i'll make calculation for you:)

regards
LC
31-03-2006, 07:38 AM
NoNickName

Re: designing a heatpump

I would suggest to use ZH series from Copeland and R407c. ZH are available with vapor injection and show a very good behaviour at high condensing pressures.
I'm designing a heater with 63°C condensing temperature for deliverying warm water at 60°C. Heating capacity 60kW, power absorbed 18kW.
31-03-2006, 10:26 PM
Andy

Re: designing a heatpump

Quote:

Originally Posted by NoNickName

I would suggest to use ZH series from Copeland and R407c. ZH are available with vapor injection and show a very good behaviour at high condensing pressures.
I'm designing a heater with 63°C condensing temperature for deliverying warm water at 60°C. Heating capacity 60kW, power absorbed 18kW.

What about a Bitzer Octagon on propane:)

More effecient compressor and a substainable refrigerant.

R134a, not a high enough effeciency:(

R410a better effeciency, but high pressures in a heat pump that will be condensing at 55 deg c:eek:

R407c just don't like it, very suspect performance, tendancy to fractionate, and only used until something better comes along, also quite a glide, not what I would be using on a water based system.

Kind Regards. Andy.
01-04-2006, 12:29 PM
NoNickName

Re: designing a heatpump

Bitzer octagon on propane is fine, as long as the unit is designed properly under the requirement of PED group 1 refrigerants.
29-09-2009, 09:35 PM
Sergey_V

Re: designing a heatpump

Quote:

Originally Posted by NoNickName

I would suggest to use ZH series from Copeland and R407c. ZH are available with vapor injection and show a very good behaviour at high condensing pressures.
I'm designing a heater with 63°C condensing temperature for deliverying warm water at 60°C. Heating capacity 60kW, power absorbed 18kW.

Hi! I am Sergey. All day I try to find information about ZH-EVI. I do not understand which TEV I must use for economizer circuit. The upper condensing temperature for ZH-EVI is app +65˚C or 28,36 bar(a). So only electronic expansion stepped valve is a correct choice. In a past I commission 4xZF48EVI we install EX5 and Alco driver for vapor injection. All time compressors were flooded throw EVI port. After that we changed EX5 by TEX and compressors rack start to work correctly. It was approximately 4 or 5 years ago. Alco Control Moscow said after that EX5 and EXD-S not suitable for economizer purpose because long time of reaction. Before that Alco do not know about such problems and recommend EX5 and Alco driver for vapor injection. May be you know such Alco elements. Alco driver is un programmable. Now is existing Carel driver where we can select different PID parameters. So as I understand TEX not exist, electronic not suitable, is not it? May be you know right solution? Best regards.
13-09-2011, 06:44 PM
paul_h

Re: designing a heatpump

CM saw your comment on their wall. My guess is they don't get them or read them, just like you :)
I'd love to tell them to fsck off too.
13-09-2011, 06:48 PM
chillerman2006

Re: designing a heatpump

Put it on the new chit chat wall mate

http://www.refrigeration-engineer.co...473#post240473

it should help as they will all start posting on that page once the number of views and posts gets high

then the mods will have some where to spot them easy
22-09-2011, 01:41 PM
MikeHolm

Re: designing a heatpump

Quote:

Originally Posted by Andy

What about a Bitzer Octagon on propane:)

More effecient compressor and a substainable refrigerant.

R134a, not a high enough effeciency:(

R410a better effeciency, but high pressures in a heat pump that will be condensing at 55 deg c:eek:

R407c just don't like it, very suspect performance, tendancy to fractionate, and only used until something better comes along, also quite a glide, not what I would be using on a water based system.

Kind Regards. Andy.

I would like to use the octogon on propane but Bitzer won't sell they scrolls in Canada for some reason
23-09-2011, 11:50 AM
MikeHolm

Re: designing a heatpump

Quote:

Originally Posted by NoNickName

Bitzer octagon on propane is fine, as long as the unit is designed properly under the requirement of PED group 1 refrigerants.

What are the PED group 1 requirements? Is it a European requirement?
23-09-2011, 02:53 PM
Josip

Re: designing a heatpump

Hi, MikeHolm :)

Quote:

Originally Posted by MikeHolm

What are the PED group 1 requirements? Is it a European requirement?

Yes it is, please check links...

http://ec.europa.eu/enterprise/secto...documents/ped/

http://www.visilume.com/technical/pr...ed-9723ec.html
http://www.google.com/url?sa=t&sourc...aUGJrQ&cad=rja
http://www.google.com/url?sa=t&sourc...Ld_qYw&cad=rja

Best regards, Josip :)
23-09-2011, 09:11 PM
MikeHolm

Re: designing a heatpump

I just looked up R290 here and it' is really hard to find. It seems the limits are 57g for any resi system, which limited it to fridges etc and 150g for commercial fridges. No word on allowing it to be used for heat pumps. A new ruling should be coming out in 90 days from the US on usage.

I guess you guys on that side of the pond have been using it for awhile. What I don't get is why the limit is set as an absolute amount? should in not be as a percentage of the total system volume?
07-10-2011, 10:02 AM
bret lee008

Re: designing a heatpump

its so nice to visit here a nice thread. Am so impressed with your such a good hard work, its definitely a good and diferent idea for others, you guys are doing good work good luck, keep it up..:)
__________
07-10-2011, 05:30 PM
chillerman2006

Re: designing a heatpump

Quote:

Originally Posted by MikeHolm

I just looked up R290 here and it' is really hard to find. It seems the limits are 57g for any resi system, which limited it to fridges etc and 150g for commercial fridges. No word on allowing it to be used for heat pumps. A new ruling should be coming out in 90 days from the US on usage.

I guess you guys on that side of the pond have been using it for awhile. What I don't get is why the limit is set as an absolute amount? should in not be as a percentage of the total system volume?

Hi Mike

I believe the amount was set based upon the average or smallest uk/eu kitchen size & the damage that can be caused by explosion.......with it being set below, what would cause structural damage

R's chillerman