EcoRenovator  

Go Back   EcoRenovator > Improvements > Geothermal & Heat Pumps
Advanced Search
 


Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 04-21-18, 04:37 PM   #1
sbkenn
Lurking Renovator
 
Join Date: Jun 2016
Location: Ireland
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Default Heatpump efficiency/reuse

Hi. Can anyone comment on what improvements have allowed heatpumps to become more efficient ? Older ones were delivering maybe 3x electric power, while newer ones are > 5x. I live on a boat in a tidal harbour, and am thinking of building a water to water pump to store heat when the tide is in. Is it worth extracting the pumps from the old systems, they have had minimal use.

Thanks in advance.

sbkenn is offline   Reply With Quote
Old 04-21-18, 06:36 PM   #2
NiHaoMike
Supreme EcoRenovator
 
NiHaoMike's Avatar
 
Join Date: Oct 2008
Location: Austin, TX
Posts: 1,154
Thanks: 14
Thanked 257 Times in 241 Posts
Default

The biggest and easiest improvement is to upsize the heat exchangers.
__________________
To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...
NiHaoMike is offline   Reply With Quote
Old 04-22-18, 05:40 AM   #3
sbkenn
Lurking Renovator
 
Join Date: Jun 2016
Location: Ireland
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by NiHaoMike View Post
The biggest and easiest improvement is to upsize the heat exchangers.
Do you mean the tube arrays ? Am I right in thinking that a much smaller array would be required for water to water than air to air ?
sbkenn is offline   Reply With Quote
Old 04-22-18, 09:21 AM   #4
CrankyDoug
Apprentice EcoRenovator
 
Join Date: Jul 2016
Location: Georgia
Posts: 100
Thanks: 6
Thanked 14 Times in 11 Posts
Default

Water/refrigerant heat exchangers are significantly smaller than air coils due to more efficient heat transfer. Tube in tube exchangers are the least expensive for your application. A shell over tube exchanger might be needed for the sea water unit so you can clean it. Sea water heat exchangers are expensive.

The newer rotary compressors are somewhat more efficient than piston units. Yours may be rotary if the system isn't very old. As Mike said, the biggest gain in efficiency with the latest systems is primarily due to larger heat exchangers. This mainly applies to air coils where the difference in size can be significant.
CrankyDoug is offline   Reply With Quote
Old 04-22-18, 02:42 PM   #5
sbkenn
Lurking Renovator
 
Join Date: Jun 2016
Location: Ireland
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I already have 400W of PV, and a home-made CHP unit for higher power AC power and battery charging. I am about to rewind a 7kVA generator to charge 24V batteries and supply AC power from the same unit. A wind turbine and standby cord-start power will follow for battery charging if main batteries get too depleted to start the CHP unit. My plan is to be completely fossil-fuel free by next winter,except for some heavier power tools. Excess power from that turbine will be routed to a resistive load, controlled to either use for heating, or overspeed control. Slowing the turbine will dramatically reduce the power that it collects from the wind. I will also experiment with an exhaust turbine driving a high-speed PMDC motor.

sbkenn is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:23 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design