COMMUNITY FORUM

johncdjr1207

10:29AM | 12/01/07
Member Since: 11/23/07
15 lifetime posts
Bvhvac
Hope some one can answer this.

I've figured out how to compare the cost per BTU of propane versus electrical heat.

Now for the heat pump. The best I can find has to do with the coefficient of performance (COP). I've found a statement that todays heat pumps have a COP between 2 and 5.

Is it correct to understand then that for each BTU of electricity that goes into a heat pump, it puts out twice as many BTU if it is rated as a COP of 2, three as many if COP of 3 etc.?

Help me understand this.

I understand the SEER rating part.

johncdjr1207

08:05AM | 12/02/07
Member Since: 11/23/07
15 lifetime posts
Then my next question is:

If my propane cost $22.40 per million btu (at 91500 btu per gal, cost of $2.05/gal) and my electricity cost $35.50 per million btu (3,414btu/kw at cost of .1214099/) then divide the cost of elect by 2 as the heat pump gives me 2 times the btu per btu consumed, then my elect cost drops to $17.75 per million btu released or removed from/into the house. Assuming the inside unit is 100 percent efficient.

Somewhere in there, it must be something having to do with the outside temperature.

Where am I off on this?

Don't take it that I am arguing on this. I am trying to understand something I know very little about.

johncdjr1207

05:17PM | 12/02/07
Member Since: 11/23/07
15 lifetime posts
I guess my basic question is: If propane cost 2.05/gal and electricity cost .1214099/kw, then which is going to be the cheapest way to heat my house this winter?

The propane is used in a none-externally vented heater( I know your opinions regarding these) and the electricity I use is in a heat pump with a SEER of 13.

I haven't figured out a way to compute the comparison.

johncdjr1207

06:16AM | 12/03/07
Member Since: 11/23/07
15 lifetime posts
Ok, I think that even I can understand that.

For the same amount of heat it is costing me $2.05 if supplied by propane and $1.30 if provided by electricity.

One last question and I'll leave you alone.

I've read that propane burns/delivers its' Btuh at 99.9 % efficiency (if not vented as in my case). If I substitute that into the calculation, it gives me a cost comparison of $3.27 divided by 2 or $1.63 (25% more economical) for the electricity. Which is still much in favor of the heat pump/electric set up (as long as the resister strips don't cut in).

If the above is correct in your opinion, no need to answer. Thanks much for the assistance.

johncdjr1207

08:39AM | 12/03/07
Member Since: 11/23/07
15 lifetime posts
Thanks. You almost dazzled me with your foot work when you said:"the efficiency of the vented and non-vented combustion is the same".

But I thought for a while. Yes, the combustion (freeing the Btuhs) is the same. The furnace efficiency is how much of that is sent into the house vs how much is released up the flue/vent/.

As for the dangers of the non-vented burners--I've lived dangerously on the edge all of my life. Why, I even drove on the interstate in Dallas/Fort Worth at go to work and go home times!!! Talk about placing your life in danger!!!!

Thanks for all the help. I've learned much from our discussion.
Click_to_reply_button
Inspiration_banner

INSPIRATION GALLERY



Post a reply as Anonymous

Photo must be in JPG, GIF or PNG format and less than 5MB.

Reply_choose_button

captcha
type the code from the image

Anonymous

Post_new_button or Login_button
Register

A simple banquette piled with pillows and lit from above with a wall sconce is a tempting spot to curl up with a favorite ... Built on a rocky island in the Drina River, near the town of Bajina Basta, Serbia, this wooden house was cobbled together ... Large steel-framed windows flood the interior of this remodeled Michigan barn with daylight. The owners hired Northworks A... Edging formed with upside-down wine bottles is a refreshing change. Cleverly and artistically involving recycled materials... A Washington State couple called on BC&J Architects to transform their 400-square-foot boathouse into a hub for family bea... Similar to the elevated utensil concept, hanging your pots and pans from a ceiling-mounted rack keeps them nearby and easy... For windows, doors, and mirrors that could use a little definition, the Naples Etched Glass Border adds a decorative flora... The thyme growing between these stepping stones adds a heady fragrance to strolls along this lush, low-maintenance garden ... Decoupage is an easy way to add any paper design to your switch plate, whether it is wallpaper, scrapbook paper, book page... Twine lanterns add pops of crafty—but sophisticated—flair to any outdoor setting. Wrap glue-soaked twine around a balloon ... When securely fastened to a tree or the ceiling of a porch, a pallet and some cushioning make the ideal place to lounge. V... Reluctant to throw away any of those unidentified keys in your junk drawer? Hang them from a few chains attached to a simp... A stripped-down model, sans screened porch, starts out at $79,000. Add the porch, a heated floor for the bath, and all the... Salvaged boards in varying widths and colors make up the dramatic accent wall in this attic space. The high-gloss white of... This garden shed has been decked out to the nines. Designer Orla Kiely created the intimate home for a flower trade show, ...
Follow_banner_a
Newsletter_icon Google_plus Facebook Twitter Pinterest Youtube Rss_icon
 
webapp2