The Homemade Heat Pump Manifesto - Page 53

Drake · 01-27-11, 12:18 PM

Minimizing indoor air pollutants can simplify/lower fresh air demand. Consider what you build with, place in your home and lifestyle. Radon levels in one's area such be considered as well.

benpope · 01-27-11, 03:10 PM

Quote:

Originally Posted by Drake

Minimizing indoor air pollutants can simplify/lower fresh air demand. Consider what you build with, place in your home and lifestyle. Radon levels in one's area such be considered as well.

Here is a short primer on volatile organic compounds (VOCs) and where they come from.

Edit: This is a bad place for this - Mods, please feel free to move it.

Xringer · 01-27-11, 04:05 PM

"air infiltration is a huge loser of heat"..

Yeah, but on the plus side, you get plenty of fresh air!!

You just reminded me of the switch plate by the front door. I never noticed it much
until the other night when it was down to about -5deg F.

I could have cooled beer on that thing!!

I plan to change the front door soon, so when the old door & frame comes out,
I'll see about adding some insulation (foam maybe) to that switch box and maybe all around the new door frame.

Now, I just need to find an R-20 door!!

Drake · 01-28-11, 02:25 PM

AC, would like to follow your results of hydro floor install if you go the cement board route . Think that is best option for shallow bed install because board is structurally more stable(internally reinforced) than cement bed under 1.5" thick. Would like to install radiant under traffic and bath area of my second floor and stay w/.5" pex(less trouble than .375 pex).

AC_Hacker · 01-29-11, 01:37 PM

Quote:

Originally Posted by Drake

AC, would like to follow your results of hydro floor install if you go the cement board route . Think that is best option for shallow bed install because board is structurally more stable(internally reinforced) than cement bed under 1.5" thick. Would like to install radiant under traffic and bath area of my second floor and stay w/.5" pex(less trouble than .375 pex).

Let's take this discussion to DIY Radiant Floor thread.

See you there.

-AC_Hacker

AC_Hacker · 01-29-11, 05:38 PM

Quote:

Originally Posted by Drake

As I am seeing your impressive "proof" HP your ground loop is pumped into a barrel(I am calling that stored water) it is than pumped thru plate HX so HP can xfer to "heat" side plate HX where water is pumped thru it to holding barrel(which I think is simulating your yet uncompleted floor loop?).

Legend

A - Car radiator with fan behind
B - Pump to circulate warm water
C - Hot HX (AKA: condenser HX, High Side HX, Liquid Side HX)
D - Refrigeration Compressor
E - Hot HX (AKA: evaporator HX, Low Side HX, Vapor Side HX)
F - Pump to circulate water
G - Barrel of water from Ground Loop
H - Pipes to & From Ground Loop

Does this make it clearer?

Here is an actual photo, but it is such a kludge that it may not be so clear.

Quote:

Originally Posted by Drake

The pumping on either side could directly drive the water loops directly(w/ no barrels) but I like the idea of water storage tanks on each side to buffer, limit cycling(like a pressure tank does) and on ground loop side to store possibly prewater water from other sources(solar, greywater?) to increase COP.

Yes, all good.

Quote:

Originally Posted by Drake

I see this needing four pumps w/ plate HX's. I wondering if direct tank to tank xfer is possible with HP and right HX's eliminating two pump loops. In an open hydronic system the loop is heated in a storage tank(any means) so feeding this tank w/ HP heat would be ideal(and serve as backup). Direct HP HX to this tank seems best. This may not be mechanically simple and and second pump loop best. Trying to follow the KISS rule.

I'm not quite following here.

Quote:

Originally Posted by Drake

I believe as I gain knowledge on refridgeration I understand the mech hdwr well but I am fully lost on the controller board you are showing. Are they for controlling power to HP and /or pumps/sensors switches or for testing data collection?(not strong on electronics).

Oh, that is my DIY data logger, 8-channels that I have used on the heat pump from time to time.

So far, the controller board is in the prototyping stage. I should have it working by the end of this weekend, with it's first-cut software.

Regards,

-AC_Hacker

AC_Hacker · 01-29-11, 07:26 PM

The Heat Exchangers that I ordered from ebay have arrived. The seller is located in Alabama, I think, and he claims to be a fast shipper. I'd have to agree, very soon after my order was placed, I got a confirmation and a tracking number. Pretty soon, they were in the front porch.

I checked them out carefully, size, plates, ports. Just like the picture, just like I ordered.

I lucked out and found a refrigerant recovery machine at a local junk store for $35 dollars, such a deal. The also made me take an 80 watt Taco circulation pump. Oh the indignities I have to put up with! I brought the recovery machine home and tested it out and it seems just fine.

After the R-22 was safely extracted and carefully stored, I carefully disassembling the 70 pint de-humidifier, that showed up on my porch with no explanation.

[* They say that if you're in harmony with the universe, then good things will come to you. I have to say, I was expecting money or beautiful babes, or maybe a pretty good car... but discarded de-humidifiers? I just wouldn't have guessed it... *]

Here are the essential parts that will become Heat Pump #2:

I handled very carefully and safely set aside the refrigerant-to-air heat exchangers to be used in future, yet-to-be-imagined projects.

The cap tube was also very carefully removed. This part has been pre-engineered to work with the compressor. My heat exchangers are a pretty close match to the compressor's rating so just brazing the heat pump back together with the new heat exchangers instead of the old (and using the old cap tube), is the easy route.

However, I did previously purchase a Thermal eXpansion Valve (AKA: TXV) to use with a heat pump project and this just might be the right project.

Finding the right size TXV for a Heat Pump with a capacity of less than a Ton is not so easy, but I discovered that Danfoss TXVs have a family of inserts that will allow the same valve body to work over a broad range, and two of those inserts are sized at 0.4 Ton and 0.7 Ton (the insert I have). I'm projecting this Heat Pump to have a capacity of .65 Ton so it looks like I'm in business.

Next step is to determine the layout...

Regards,

-AC_Hacker

Drake · 01-29-11, 09:53 PM

The first picture is of an air to water HP is it not and not the HP pictured earlier in the thread? Kudos on the collector find. What does one look like? The type of HX I am thinking of(if there is one) would be put inside storage tank. No pumping. Is the TXV for adjusting Refrig balance?

AC_Hacker · 01-30-11, 02:57 AM

Quote:

Originally Posted by Drake

The first picture is of an air to water HP is it not and not the HP pictured earlier in the thread?

Yeah, it's Heat Pump #1. It's water-in-water-out, In the photo I'm using a car radiator and a fan in place of a radiant floor, because I haven't built the radiant floor yet. As it is, I'm producing useful heat, and I can study the impact that running the heat pump has on ground temp.

Quote:

Originally Posted by Drake

Kudos on the collector find. What does one look like?

Are you referring to the solar collectors I have in the side yard, or do you mean the refrigeration recovery machine?

Quote:

Originally Posted by Drake

The type of HX I am thinking of(if there is one) would be put inside storage tank. No pumping.

There is some outfit that makes a long twisted copper heat exchanger that will fits inside a hot water tank. One of those could possibly be used as you suggest.

Quote:

Originally Posted by Drake

Is the TXV for adjusting Refrig balance?

Just so. With a captube setup, adjustment is not so easy because you need to brake the refrigeration circuit, braze on a new captube of a different length and/or diameter, then re-charge he system.

The TXV has an adjustable screw. Much easier.

-AC_Hacker

Drake · 01-30-11, 10:22 AM

Yes, the refrigerant collector. Can you use it to collect refrig from multiple discarded units to meet needs of new(DIY) system if needed? On the HX direct to tank, your thoughts on trying a radiator coil at bottom of tank. I know it designed for air xchg but as water is better conductor it should work at least as well I would think and thermo cycling in tank should provide water movement. Coil from AC or maybe dehumdfr?

If compr and cap tb are matched and sized for heat demand length of refridg line is not also determined(set length) is it? I'm making this assumption from split AC installs where distance between units varies.

01-29-11, 07:26 PM	#527
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 724 Times in 534 Posts	Heat Pump #2... The Heat Exchangers that I ordered from ebay have arrived. The seller is located in Alabama, I think, and he claims to be a fast shipper. I'd have to agree, very soon after my order was placed, I got a confirmation and a tracking number. Pretty soon, they were in the front porch. I checked them out carefully, size, plates, ports. Just like the picture, just like I ordered. I lucked out and found a refrigerant recovery machine at a local junk store for $35 dollars, such a deal. The also made me take an 80 watt Taco circulation pump. Oh the indignities I have to put up with! I brought the recovery machine home and tested it out and it seems just fine. After the R-22 was safely extracted and carefully stored, I carefully disassembling the 70 pint de-humidifier, that showed up on my porch with no explanation. [* They say that if you're in harmony with the universe, then good things will come to you. I have to say, I was expecting money or beautiful babes, or maybe a pretty good car... but discarded de-humidifiers? I just wouldn't have guessed it... ] Here are the essential parts that will become Heat Pump #2: I handled very carefully and safely set aside the refrigerant-to-air heat exchangers to be used in future, yet-to-be-imagined projects. The cap tube was also very carefully removed. This part has been pre-engineered to work with the compressor. My heat exchangers are a pretty close match to the compressor's rating so just brazing the heat pump back together with the new heat exchangers instead of the old (and using the old cap tube), is the easy route. However, I did previously purchase a Thermal eXpansion Valve (AKA: TXV) to use with a heat pump project and this just might be the right project. Finding the right size TXV for a Heat Pump with a capacity of less than a Ton is not so easy, but I discovered that Danfoss TXVs have a family of inserts that will allow the same valve body to work over a broad range, and two of those inserts are sized at 0.4 Ton and 0.7 Ton (the insert I have). I'm projecting this Heat Pump to have a capacity of .65 Ton so it looks like I'm in business. Next step is to determine the layout... Regards, -AC_Hacker Attached Thumbnails __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 01-29-11 at 07:45 PM..*

01-27-11, 12:18 PM	#521
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	Minimizing indoor air pollutants can simplify/lower fresh air demand. Consider what you build with, place in your home and lifestyle. Radon levels in one's area such be considered as well.

01-27-11, 04:05 PM	#523
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	"air infiltration is a huge loser of heat".. Yeah, but on the plus side, you get plenty of fresh air!! You just reminded me of the switch plate by the front door. I never noticed it much until the other night when it was down to about -5deg F. I could have cooled beer on that thing!! I plan to change the front door soon, so when the old door & frame comes out, I'll see about adding some insulation (foam maybe) to that switch box and maybe all around the new door frame. Now, I just need to find an R-20 door!!

01-28-11, 02:25 PM	#524
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	AC, would like to follow your results of hydro floor install if you go the cement board route . Think that is best option for shallow bed install because board is structurally more stable(internally reinforced) than cement bed under 1.5" thick. Would like to install radiant under traffic and bath area of my second floor and stay w/.5" pex(less trouble than .375 pex).

01-29-11, 09:53 PM	#528
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	The first picture is of an air to water HP is it not and not the HP pictured earlier in the thread? Kudos on the collector find. What does one look like? The type of HX I am thinking of(if there is one) would be put inside storage tank. No pumping. Is the TXV for adjusting Refrig balance?

01-30-11, 10:22 AM	#530
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	Yes, the refrigerant collector. Can you use it to collect refrig from multiple discarded units to meet needs of new(DIY) system if needed? On the HX direct to tank, your thoughts on trying a radiator coil at bottom of tank. I know it designed for air xchg but as water is better conductor it should work at least as well I would think and thermo cycling in tank should provide water movement. Coil from AC or maybe dehumdfr? If compr and cap tb are matched and sized for heat demand length of refridg line is not also determined(set length) is it? I'm making this assumption from split AC installs where distance between units varies.