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View Full Version : Heat Pump, yes or no?

mariorenato
01-14-2010, 11:32 AM
Hi,

Found this forum on google, and after reading a little bit, I think here my doubts will be cleared :)

Just moved to a new house. It's ready with natural gas, but for some reason, it will only be available in my house in 2 years or so.

Since I have must have too much spare time, and some cute monitoring gadgets, I started to make some cute graphs to aid in my descision

This one is from the living room. Some 30 square meters (320 sqrfoot).

http://i47.photobucket.com/albums/f182/mariorenato/sala.png

This has been in January, and the outside temps were between 0ºc and 10ºc (32F and 50F)

The heat sources are a resistive heater of 2KW, me 100W, one lcd 250W and a couple of lamps, 40W each

At 19.30, the temp was 15.2ºC (59F) and at 22h it was already on the setpoint of 21ºC(70F).

At this point it started a duty cycle of about 25minutes on, 35 minutes off

KW here is 0,12€, or 0,06€ from 22h to 8 in the mornig

So, from 19.30 to 22h I sent 2kw*2.5hours *,12€/KW = 0,6€. The rest of the time, untill 1h another 0,6€

So, 1.2€ to have a warm room from 20h to 2h30, time at witch the temps got below 18.5ºc (65.3F)

Assuming every day I'm just at night on the room it would be some 36€ to have the room warm 5-6hours per day.

On the bedroom I have another 1kw resistive heater with a timer.

On at 11pm, off at 3am.

4h * 1kw *.12€/KW = 0,5€

http://i47.photobucket.com/albums/f182/mariorenato/quarto.png

In the mornign it connects again..

When I'm fully moved to this house and want to have it all (130 sqmeter, 1400 sq foot), it wount be cheap to have it all hot using resistive heaters....

So I searched a bit and found a nice aplication from the manufacturer Daikin

http://i47.photobucket.com/albums/f182/mariorenato/20fcc2d7.png

In the parameters I used 120sqmeters, and water betwen 30-55ºC

In the other menus I filled the costs for the alternatives (fuel, natural gas, electricity...)

Here the electricity rates:.

http://i47.photobucket.com/albums/f182/mariorenato/1-3.png

Here a lower temp when no-one is at home
http://i47.photobucket.com/albums/f182/mariorenato/2-4.png

misc:
http://i47.photobucket.com/albums/f182/mariorenato/3-3.png

http://i47.photobucket.com/albums/f182/mariorenato/4-3.png

Diesel prices
http://i47.photobucket.com/albums/f182/mariorenato/5-2.png

results in the next post

mariorenato
01-14-2010, 11:38 AM
Here I have the several options
http://i47.photobucket.com/albums/f182/mariorenato/6-2.png
explanations:
http://i47.photobucket.com/albums/f182/mariorenato/6a.png
http://i47.photobucket.com/albums/f182/mariorenato/6b.png

The most important result is the cost of having the whole house hot
http://i47.photobucket.com/albums/f182/mariorenato/9-1.png

300€ per year.. 30€ per month in average

In the coldest month, january, I'd spend 85€ to heat the hole house.. more or less the same has heating 2 compartments some hours a day with resistive heating :S

http://i47.photobucket.com/albums/f182/mariorenato/11.png

Alternat solucions costs:

http://i47.photobucket.com/albums/f182/mariorenato/10-1.png
http://i47.photobucket.com/albums/f182/mariorenato/12.png
http://i47.photobucket.com/albums/f182/mariorenato/13.png
http://i47.photobucket.com/albums/f182/mariorenato/7-2.png

So... Is it worth the cost of installing a HP? I believe a 10kw solution will cost about \$.. Do I keep the current gas boiler as backup and sanitary water supplier, or I give it back to the builder,, and place a 200l tank?

EBear
01-14-2010, 11:58 AM
HelloZ,
By chance have you considered converting to propane?

GL, EBear.

mariorenato
01-14-2010, 12:05 PM
Its an apartment..

Right now I'm just using the boiler to heat sanitary waters with butane.

I believe regulations here forbid you to have propane in the house, just outside

lentz
01-14-2010, 12:07 PM
Just burn a candle in each and I think you will be warm.

mariorenato
01-14-2010, 12:19 PM
Just burn a candle in each and I think you will be warm.

nah... too little power

the steady-state heat release rate from the candle was
calculated as 77 +- 9W.
from:http://fire.nist.gov/bfrlpubs/fire05/PDF/f05141.pdf

I'd need about 100 candles, and then I don't think the air inside would be very good..

gary_g
01-14-2010, 02:08 PM
There's not enough graphs in this post to answer your question :eek: