I have a customer in California who is putting in solar, and currently has a late model propane furnace.  They do not want air conditioning, nor the expense of switching to a heat pump system.

Does anyone have any thoughts or experience adding a secondary heat coil to the propane furnace?  The heat load for the house is 32K BTUs.  20 watts equals 68K BTUs.

Who might manufacture an add-on electric heat coil?  The plan is that the electric heat will handle normal loads, but the propane will be there if needed for additional heat at very cold times (not often).

I would appreciate any input.

Rich

Views: 2317

Reply to This

Replies to This Discussion

The add-on electric heat coil has morphed into a ductless heat pump that eliminates duct loss, pressure-related convective losses associated with both the propane 80%'er at best before duct losses whack it and also the hapless unitary heat pumps that were noisy blends of old technologies and centralized mistakes of last century. Dump the 80% er, the tank and the smell. Drop the ducts, seal the penetrations. Run the whispering suit-case. With the sun.

I can't blame them for wanting to avoid the expense and penalties inherent in that old time unitary, ducted heat pump- noisy, needs back-up, expensive! But look at mini-splits for significantly higher HSPF, better than anything in the strip heat arsenal, like COP of 3.8. handling low exterior temperatures without need for backup, invertor driven to maximize efficiency and minimize racket while eliminating health, safety and environmental issues.  and running off ~ 450 to 1000 watts in Cali winter, 2 - 4 more panels of 250 watts each worth to go net zero. Why not go for the whole NINE yards?

Adding electric resistance coils in the ducts would likely have caused the problem discussed in the post;

How Do We Make Energy Efficiency Sexy, or at Least Interesting?

With your customer ending up with a higher electric bill.

Adding Solar often drives people to want to convert from gas to electric, solar installers often encourage this.

For smaller houses, and very energy efficient houses, and conservative occupants, switching to electric can be a good choice, but it increased the primary (source) energy consumption at the power plant (aprox 3x the energy at the power plant than used at the house). Of course heat pumps can lower the site energy with minimal impact on the source energy, and are almost always less expensive to run than propane.

Switching to ductless mini-splits eliminates the duct losses. Although air tight ducts in conditioned space have no loss either. The problem can be distribution, and many builders install small bath fans w&w/o ducts to help distribute the heating / cooling. Having an energy efficient home will help make distribution easier.

Have they, or are they doing any efficiency upgrades to the house to reduce energy use?

RSS

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.

Latest Activity

Hal Skinner replied to Kurt Shafer's discussion Where can I find the best radiant barrier to install under my roof?
"I just posted a statement and pictures of a home in Yuma AZ.  This is one I did 10 years…"
7 hours ago
Hal Skinner added a discussion to the group The RCC Classroom (Radiant Control Coatings)
7 hours ago
Tom Mallard replied to Kurt Shafer's discussion Where can I find the best radiant barrier to install under my roof?
"Anything done to raise the roofing off the sheathing works to reduce the high temperatures in the…"
9 hours ago
Michael Dunseith posted a photo

http://www.prattcenter.net/energy-champions-launch-party

Senator Kevin Parker poses with Pratt Center's Green Jobs Green New York Project Coordinator Elana…
16 hours ago
Michael Dunseith posted a status
16 hours ago
Rob Madden, Solar Home Broker posted a blog post

Phoenix 3rd Quarter Solar Resale Statistics Continue to Impress

Phoenix solar home sales were up during the third quarter of 2014, including the resale of homes…See More
yesterday
Everblue posted a status
"Green job alert! Energy Auditor in Baltimore, MD with Advanced Green Home Solutions. Check it out: http://bit.ly/1xhQuXO"
yesterday
Chris Clay replied to Isaiah Borel's discussion Blown Cellulose VS Blown Fiberglass in the Attic
"The Cold Climate Housing Research Center in Fairbanks, AK has alot of information about this…"
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service