RemRate allows for a ground source heat pump and you can couple it to the domestic hot water system.  However I need to convert the Water Furnace's 5.0 COP to an equivalent EF.  Any ideas?????

Views: 300

Reply to This

Replies to This Discussion

One would be tempted to put in 500%, but refrain, the stated COP is just for the unit, not the HP system, which will include pumping power and other distribution losses.  Probably system COP closer to 3.

Hi Elizabeth -- If you look at the last page of this article (, you'll see a nice description of how EF is measured.  From this, and factoring in the additional consumption that Michael mentioned, you can probably come up with a reasonable approximation of the EF for your scenario.  The toughest part may be to figure out the standby losses, if the DHW is a tank-type system.

Note that in REM the EF is entered as a decimal, not a percentage -- and for a heat pump, the decimal will be larger than 1.0.

I was looking at REM/Rate and the GSHP only needs COP entered. It looks like you only need to model the type of water heater you are using for EF and also check desuperheater in the heat pump section if they are coupled.
Also to add the pump watts. Are you using the GSHP to supply 100% of the domestic hot water?
Thanks for the help.  Didn't want to reinvent the wheel if someone had already been down this path.


Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network.

Latest Activity

Profile IconWilliam Smith and Juan Jose Palacios joined Home Energy Pros
2 hours ago
Eric Kjelshus replied to John Gillis's discussion Energy Savings of Whole House Fans vs. Air Conditioners in SoCal Featured on New 'Ask This Old House' Season in the group News & Announcements
"2000 SF house in Kansas City needs a 36" whole house fan or about 8,000 CFM takes a 1/4 HP fan…"
4 hours ago
Eric Kjelshus joined Diane Chojnowski's group

News & Announcements

Share your news and announcements with the community in this group.See More
4 hours ago
Eric Kjelshus replied to David Byrnes's discussion Insulation machine preferences
"If you find over heating look at voltage/amp draw very hard.    I find if you have…"
4 hours ago
Colin Genge posted events
6 hours ago
Adrienne DeAngelo posted an event

GreenPoint Rated CORE Training at Best Western Plus Marina Shores Hotel

October 15, 2015 to October 17, 2015
Increase your certifications or get to know the GreenPoint Rated system so that you can work more…See More
7 hours ago
Colin Genge replied to John Carton's discussion Smoke Puffer stick
"Retrotec Smoke Puffer is available for pickup from Energy Federation. They will not ship them due…"
7 hours ago
Colin Genge updated an event

Retrotec is exhibiting at the ACI National Home Performance Conference & Trade Show at Austin Hilton

April 4, 2016 at 8am to April 7, 2016 at 5pm
The 2016 ACI National Home Performance Conference and Trade Show is coming to Austin, TX April…See More
7 hours ago

© 2015   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service