Help design my new system please - Page 28

buffalobillpatrick · 03-25-14, 08:28 PM

Does this thing work well? It's got good 5 star reviews.
Compressor Saver CSR U1 Hard Start Capacitor

http://www.amazon.com/Compressor-Sav...productDetails

http://ecorenovator.org/forum/attach...1&d=1395797278

buffalobillpatrick · 03-25-14, 09:08 PM

My Copeland compressor ZP24K5EPFV830
RLA = 13.4A, LRA = 64A, Copeland stays Inrush current = LRA

jeff5may · 03-26-14, 03:51 AM

Straight from emerson:
http://www.emersonclimate.com/Docume...TLE_Series.pdf

I like the supco hard start kits myself. They use a potential relay to switch the start cap.

If you are going to use a VFD, you won't need a hart start kit.

Mikesolar · 03-26-14, 05:19 AM

Hard start kits are used for pots that are outdoors in the cold or have had design issues where they are having trouble getting going. A well designed system won't need it.

A soft start is better because it is used where you have a limited current supply or low line voltage such as in some residential situations but, as Jeff says, there is no need for either if you have a VFD.

Unless you have an old 60Amp service and don't like dimming lights when the pot starts, you shouldn't need either one.

NiHaoMike · 03-26-14, 08:26 AM

If you do get a hard start kit, the 5-2-1 (or any based on a potential relay) would be your best bet. It's unlikely you'll actually need one as R290 would mean less pressure to start against.

https://www.youtube.com/watch?v=jFFRpxFkpcM

buffalobillpatrick · 05-25-14, 05:49 PM

Mikesolar, on page 12 your:

"3.65gpm with a 20F dT is 36,500btu x 2 loops is 73Mbtu. I don't know where 180Mbtu comes from"

We are looking at this wrong, I want the delta-T between the solar tank / water coming out of pex HX to be as SMALL as possible.

I reduced the flow to 2gpm based on the small 53W 240VAC .22A pumps I bought.

Head Loss @ 2gpm through 3/4" pex 250' long:

HL = K x C x L x F^1.75
K = .0034, C = .933, L = 250, F = 2gpm (2^1.75 = 3.3636)
HL = 2.67'

Based on Gary's 20*F delta-T @ 2gpm with 300' of 1" pex,
I should get about 15.6*F delta-T

So if my heat pump takes 10*F (10*F is just a guess)
out of this HX 4 x 500 x 10 = 20,000 btu

Mikesolar · 05-25-14, 06:09 PM

The dT through the HP is totally different than through the load (floor) and having the buffer tank means the two are hydraulicly disconnected. You can run the HP and the floor at different flow rates. You want to have a particular drop over a set length for comfort reasons. If you have set load and you are trying to have only a really low dT, your flow rate will have to be ridiculously high especially for the standard 250' loop length. There is nothing wrong with 15 or 16F dT or anywhere from 10F to 25F but remember that if you double the pump speed you will quadruple the needed pump power. It is a balancing act.

buffalobillpatrick · 05-25-14, 06:48 PM

"We are looking at this wrong, I want the delta-T between the solar tank / water coming out of pex HX to be as SMALL as possible."

I'm not talking about the floors, I'm talking about the pex HX inside the 1,000g solar tank that will feed the HP.

Mikesolar · 05-25-14, 06:55 PM

Sorry about that. 6F is a reasonable dT for a HP but some of this will be trial and error and I doubt 2 GPM will be enough to provide the proper cooling for the HP. It is typically around 3GPM/ton

buffalobillpatrick · 05-25-14, 07:31 PM

It will be 2gpm minimum in each loop, possibly 3gpm in each of the 2 loops, sooo 4-6gpm total.

I plan to put 2 of these 53W pumps in series on the evaporator and 2 in series on the condenser. I got them for $40 each + shipping

03-25-14, 08:28 PM	#271
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Does this thing work well? It's got good 5 star reviews. Compressor Saver CSR U1 Hard Start Capacitor http://www.amazon.com/Compressor-Sav...productDetails http://ecorenovator.org/forum/attach...1&d=1395797278 Attached Thumbnails Last edited by buffalobillpatrick; 03-25-14 at 08:55 PM..

03-25-14, 09:08 PM	#272
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	My Copeland compressor ZP24K5EPFV830 RLA = 13.4A, LRA = 64A, Copeland stays Inrush current = LRA Last edited by buffalobillpatrick; 03-26-14 at 01:33 PM..

05-25-14, 07:31 PM	#280
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	It will be 2gpm minimum in each loop, possibly 3gpm in each of the 2 loops, sooo 4-6gpm total. I plan to put 2 of these 53W pumps in series on the evaporator and 2 in series on the condenser. I got them for $40 each + shipping Last edited by buffalobillpatrick; 05-25-14 at 07:33 PM..

03-26-14, 03:51 AM	#273
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Straight from emerson: http://www.emersonclimate.com/Docume...TLE_Series.pdf I like the supco hard start kits myself. They use a potential relay to switch the start cap. If you are going to use a VFD, you won't need a hart start kit.

03-26-14, 05:19 AM	#274
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	Hard start kits are used for pots that are outdoors in the cold or have had design issues where they are having trouble getting going. A well designed system won't need it. A soft start is better because it is used where you have a limited current supply or low line voltage such as in some residential situations but, as Jeff says, there is no need for either if you have a VFD. Unless you have an old 60Amp service and don't like dimming lights when the pot starts, you shouldn't need either one.

05-25-14, 05:49 PM	#276
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Mikesolar, on page 12 your: "3.65gpm with a 20F dT is 36,500btu x 2 loops is 73Mbtu. I don't know where 180Mbtu comes from" We are looking at this wrong, I want the delta-T between the solar tank / water coming out of pex HX to be as SMALL as possible. I reduced the flow to 2gpm based on the small 53W 240VAC .22A pumps I bought. Head Loss @ 2gpm through 3/4" pex 250' long: HL = K x C x L x F^1.75 K = .0034, C = .933, L = 250, F = 2gpm (2^1.75 = 3.3636) HL = 2.67' Based on Gary's 20F delta-T @ 2gpm with 300' of 1" pex, I should get about 15.6F delta-T So if my heat pump takes 10F (10F is just a guess) out of this HX 4 x 500 x 10 = 20,000 btu

05-25-14, 06:09 PM	#277
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	The dT through the HP is totally different than through the load (floor) and having the buffer tank means the two are hydraulicly disconnected. You can run the HP and the floor at different flow rates. You want to have a particular drop over a set length for comfort reasons. If you have set load and you are trying to have only a really low dT, your flow rate will have to be ridiculously high especially for the standard 250' loop length. There is nothing wrong with 15 or 16F dT or anywhere from 10F to 25F but remember that if you double the pump speed you will quadruple the needed pump power. It is a balancing act.

05-25-14, 06:48 PM	#278
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	"We are looking at this wrong, I want the delta-T between the solar tank / water coming out of pex HX to be as SMALL as possible." I'm not talking about the floors, I'm talking about the pex HX inside the 1,000g solar tank that will feed the HP.

05-25-14, 06:55 PM	#279
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	Sorry about that. 6F is a reasonable dT for a HP but some of this will be trial and error and I doubt 2 GPM will be enough to provide the proper cooling for the HP. It is typically around 3GPM/ton