Heat Pump Hot Water Powered By TST5?

[jelloir]

I have been looking at water heating options for my home. Evacuated tube solar hot water is expensive at $5000-$6000 to install after rebates so I began looking at heat pumps which will cost around $1500-$2000 including rebates, install should be about $500. By making this decision I now have increased budgets for Amorphous panels for my planned TST5 powered solar electricity setup.

what I hope to achieve is power the heat pump water heater using my TST5 setup. I figure if I scale my TST5 setup correctly I should be able to heat the water during the day when the sun is out without drawing from the batteries, on cloudy days hopefully the amorphous panels will supply enough power to only draw lightly from the batteries.

I theorize that since the ambient air temperature during the day is warmer that the heat pump would be more efficient, when powered from the grid the recommendation is to run them at night during off peak time to save some money but is less efficient, but the opposite it true if using solar electricity. I will insulate the heat pump and piping properly as well.

The specs are below, basically it's 1150W, Rated current 5.2A, Max current 6.5A, Compressor starting current 30A



http://www.siddonssolarstream.com/products/all-in-one

Information about the power is listed below:

Your Solarstream will require an approved, standard 240V 15AOn / Off switch or Junction Box in close proximity to the heater. It may be connected to a Standard Domestic tariff or Off Peak or Smart Meter connection. If the unit is connected to an Off Peak connection, the minimum power availability should be at least 6 hours per day.

Can anyone offer some insight and recommendations on this idea? I'm thinking of getting a 24V 160A TST5 to cover myself for future power needs as well as this heat pump.

Thanks

James

[Tom C]

James,

Have you done the calculations for the entire house? also look into a "soft start" motor for the pump it will reduce the surge current a lot. we put soft start motors everywhere we can where I work.

Tom C

[jelloir]

James,

Have you done the calculations for the entire house? also look into a "soft start" motor for the pump it will reduce the surge current a lot. we put soft start motors everywhere we can where I work.

Tom C

After making my house more efficient my estimate for power is 20kWh per day (including the heat pump hot water) but hopefully a lot lower, that's an overestimate. I would estimate that peak usage might draw 3000-4000 Watts at any one time, but I will train my family members not to use dishwashers, oven's, kettles, washing machines all at the same time, so again I should be able to reduce this number.

Thanks for the tip about the soft start motor, I'll take a look.

[Tom C]

DC appliances will help also....
Tom C

[bigmotherwhale]

I wanted to do a heat pump powered by solar panels too, my idea was to cool the solar panels with the heat-pump and make hot water, this way you will have a positive feedback effect of the increased efficiency of the panels at lower temperatures making them last longer and output more, especially relevant if you live in a hot country. also you could implement a condensation collection off the panels for water from air extraction at dawn.
when i get a solar panel i am going to install the innards of a freezer with some insulation on the back and regas with propane or butane.

Heat pumps are the easiest "free energy" there is, its not surprising that ammonia hydrogen evaporation refrigeration was pretty much phased out, cold from heat heat from cold - very useful indeed

[bigmotherwhale]

also could you not drive the compressor by a rotoverter style setup? seems ideal as the load on the motor should vary by a very small amount
and maybe get a gas kettle and a bio-gas digester? that should reduce the peak loads,
could you possibly drive a buffer from the panels like a battery reserve or compressor/compressed air generator to deal with peak load?

[Tom C]

http://www.sundancecustomrv.com/Ammo...rigerators.pdf

[bigmotherwhale]

http://www.sundancecustomrv.com/Ammo...rigerators.pdf

good article, thanks tom

[jelloir]

I got the heat pump hot water installed. Attached is pics of the new heat pump and the old decommissioned electric. The cylinder was $3400AU including fittings and delivery; I received a $1740AU govt rebate so my actual cost was $1660AU. The plumber charged $550AU which I felt was very reasonable for the work required. I dug a trench for the cold water inlet from the mains and created the pad for the new cylinder.



I had the cylinder plumbed into the pipes under the kitchen sink so instead of waiting 40 seconds for hot water to arrive from the faucet it's now 4 seconds! The old electric cylinder was positioned on the opposite side of the house away from all the household hot water outlets so that in itself would have lowered the efficiency. We aren't the original home owners, I have no idea why it was like that.

I am planning on insulating the new tank and may look at pre-heating the cold water inlet using black polythene pipe or similar systems used to heat water into swimming pools. But if I need to pump it up on the roof it might cancel out any energy saving benefit pre-heating provides.

Now once I get a supplier of Amorphous panels who will stay in business longer than the warranty I can get a TST5 ordered and start my off grid project!

Thanks,

James