Solar Panels V Heat Pump on Cylinder

Squeaksoutloud

Hi,

I posted in the plubing section but got no replies on this query:

http://www.boards.ie/vbulletin/showthread.php?p=81051600

Can any one help this is my query from the other thread:

I am looking at installing a Sofath Hot Water System instead of solar panels. My plumber tells me that it is much better than using solar panels.

This is the product here:

http://www.sofath.com/english/domest...-heat-pump.htm

It is basically an air source heat pump connected directly to a cylinder.

Anyone have any feedback or advice on this system versus solar panels? Seems like hot water 365 days a year at a very low runnin cost..

Cheers - would love to hear from someone with a similar system installed.

quentingargan

Solar panels do the job with near zero energy cost during the summer when your heating is off. In winter time, your heating system - whatever it is - will heat the water relatively efficiently because it is running anyhow to heat the house. To my mind, heat pumps are at their most efficient getting water up to about 40C for heating UFH etc., and not particularly efficient at getting water up to 60 as required for domestic hot water.

I would question whether it is worth the complexity of having a heat pump for domestic hot water only.

You are right to look for someone who has such a system - specifically to find out the running costs perhaps, but looks like nobody has responded.

freddyuk

I have a similar unit that I have in storage as I have not had time to try it out. It has a single coil for dhw. There is also a twin coli version that allows you to connect a solar thermal system into the unit and I wish I had that version.
You need to understand the intake air is cooled and dried so heat will be removed from wherever you take the air in and cooler air will be expelled. Taking the input from a loft /kitchen would likely use warm air that needs to be removed and turned into hot water and the cooler air returned to a room that needs cooling or to the outside.
Ideally a computer room could support a unit like this as it needs cooling and this unit would replace the air conditioners required for computer rooms. Or a commercial kitchen where warm damp air needs cooling.
The problems occur when you have to take outside air ie. not cooling the inside and this air is cold in winter which means the system will not be efficient.I have an unheated storage unit with an immersion based water heater so I plan to try the unit here and measure the efficiency.
55c will be plenty hot enough for this purpose and will run cheaper than an immersion I would expect. These units are not that expensive and have limitations if the incoming air is too cold.