ASHP question

[Xringer]

That bust of heat, when you first turn on a mini-split sure sounds like what my Sanyos..
When they start up from OFF mode, the controller wants to blast out a bust of hot air.

I think this "feature" is incorporated into Sanyos, as a selling point.
(They think we want instant gratification).
In the Sanyos that I have, the Big Blast is over-done and the power use
can soar to over 3.5 KW if allow to run it's full cycle..


Does your remote have a remote-sensor Off-On feature?
On mine, it's the little button down at the bottom, marked Sensor.
That will force my IDU to use it's own built-in thermistor,
and not use the temperature reading from the remote's thermistor..

That might enable you to see if their is any problem with remote IR comms.

http://ecorenovator.org/forum/attach...1&d=1325435828

[poleikleng]

Originally Posted by Xringer

That bust of heat, when you first turn on a mini-split sure sounds like what my Sanyos..
When they start up from OFF mode, the controller wants to blast out a bust of hot air.

I think this "feature" is incorporated into Sanyos, as a selling point.
(They think we want instant gratification).
In the Sanyos that I have, the Big Blast is over-done and the power use
can soar to over 3.5 KW if allow to run it's full cycle..


Does your remote have a remote-sensor Off-On feature?
On mine, it's the little button down at the bottom, marked Sensor.
That will force my IDU to use it's own built-in thermistor,
and not use the temperature reading from the remote's thermistor..

That might enable you to see if their is any problem with remote IR comms.

Xringer,

I do not think my remote has this feature and I have not found any mention of it in my operators manual.


Poleikleng

[Xringer]

That's too bad.. But, I wonder if there is any mention of what the system does,
if the remote is out of line-of-sight or the battery dies??

IIRC, the Sanyos will hold at the last setting received, by using the on-board IDU's sensor as it's thermostat.

With all the nice solar we are getting today, the Sanyos are hardly running this PM..
Time to go out for a nice long walk.. (or Bike ride)!

[eco_fred]

Originally Posted by Student 07

Hi,
I spoke with a representative at Aqua therm and he was very helpful. I told him of my plans to use a swimming pool /spa heat pump to supply hot water for my space heating and DHW needs.

He started by stating that their Heat pump was designed for swimming pools not water tanks. To make it work for my application would require numerous modifications. The high pressure switch would have to be changed to allow the water to get hotter, this would require modifications. Then he wasn’t sure the compressor would be able to reach a higher pressure or what it would do to longevity. The flow rate could be changed by swapping in a smaller hp motor and pump (Hopefully this would lower the required KW) . Of course all of these modifications would require that the controller would have to be modified to operate the new equipment.

You would be swapping out a lot of parts, basically building a new heat pump, and then its performance may still be questionable. I'm not real keen on the idea of spending $3000 for a new heat pump then hacking it up and hoping it works. I am beginning to think there may be better alternatives.

The mini split ODUs are designed for higher temps and are designed for residential use, so they would be ideal. I wonder if the refrigerant from a mini split could be run to a Reverse Cycle Chiller to produce hot water. Or could some other kind of heat exchanger be hooked up to the ODU?

Looks like I have more research to do.

owkeeej i cant see any problems ...
1 i think a swimming pool consist of water ??
2 hp switch is to protect the compressor , but what he means is the temp of the water if you want to go highter then 30 40 degrees search other apps because the cop wont be that good anymore and that is why you use heat pumps...

[poleikleng]

Originally Posted by Xringer

That's too bad.. But, I wonder if there is any mention of what the system does,
if the remote is out of line-of-sight or the battery dies??

IIRC, the Sanyos will hold at the last setting received, by using the on-board IDU's sensor as it's thermostat.

With all the nice solar we are getting today, the Sanyos are hardly running this PM..
Time to go out for a nice long walk.. (or Bike ride)!

Xringer,

The manual states the batteries last 1-year, the heat pump has been in use 8-months also, the batteries were 1.44 volts when I checked them with the multimeter.

The troubleshooting section stated:

Symptom: The unit operates differently from the Remote Controller's setting

Problem: Are the Remote Controller's batteries dead?

Problem: Are the Remote Controller's batteries loaded properly?

I sent an email to the company that installed the unit describing the issue and I think I will also call the Fujitsu service and see what they recommend.

Poleikleng

[Xringer]

As I said before above:

I can't understand why your temp would drop to 62, if your remote was set to 70..
If your system (21,600 BTUh heating) is correctly sized for your home,
then something is not working right.
(I'm assuming your home has good insulation and not a lot of sq feet to heat).


You said your system works well for cooling.. I found the same thing with the Sanyos.
I could chill beer in here during the summer..

But, when it's cold, the difference between the indoor and outdoor temperature is pretty big..
So, it seem that heating is a lot harder than cooling..

My point is, your ASHP might be fine doing the cooling, but it might be undersized for the task of heating.

Maybe, a quick and easy way to tell if it's undersized, is to monitor the unit on a cold night.

On Tuesday night, it's going to get real cold. Leave it set for 70 and watch it.
Does the fan speed go up and down?
Does the system go into very low speed when the room goes slightly above 70??
Those would be good signs.. But, if the unit runs a high power and stays there, never slowing down.
That means, you system isn't up to the task. (Undersized or defective).
Or, the outside temperature is dropping so fast, the system can't keep up. (Undersized or defective)

[Xringer]

Does you system have an LED blink code to let you know when it's defrosting?

When Sanyo#1 defrosted a few times, it got pretty cool in here..
I never noticed the LED flashing, until I hooked an alarm to detect high power use..

Recently we've had some really humid days when it was near freezing.
Not great operating conditions for ASHPs..

If you don't have an LED alert, then you might notice a little cold air
coming out of your unit (unless it has a heater element).
Then, you can go outside and check the coil for frost..

[poleikleng]

Originally Posted by Xringer

Does you system have an LED blink code to let you know when it's defrosting?

When Sanyo#1 defrosted a few times, it got pretty cool in here..
I never noticed the LED flashing, until I hooked an alarm to detect high power use..

Recently we've had some really humid days when it was near freezing.
Not great operating conditions for ASHPs..

If you don't have an LED alert, then you might notice a little cold air
coming out of your unit (unless it has a heater element).
Then, you can go outside and check the coil for frost..

Xringer,

The 1.5-ton unit does not have a defrost LED (correction, the units operation indicator lamp will flash during automatic defrosting mode). We have experienced the defrost cycle and as you mentioned during the cycle it does get cool.

How are you planning the upcoming cold spell? Will you turn on your oil furnace to a set temperature and also run your heat pumps?

Poleikleng

[poleikleng]

Originally Posted by Xringer

As I said before above:

I can't understand why your temp would drop to 62, if your remote was set to 70..
If your system (21,600 BTUh heating) is correctly sized for your home,
then something is not working right.
(I'm assuming your home has good insulation and not a lot of sq feet to heat).


You said your system works well for cooling.. I found the same thing with the Sanyos.
I could chill beer in here during the summer..

But, when it's cold, the difference between the indoor and outdoor temperature is pretty big..
So, it seem that heating is a lot harder than cooling..

My point is, your ASHP might be fine doing the cooling, but it might be undersized for the task of heating.

Maybe, a quick and easy way to tell if it's undersized, is to monitor the unit on a cold night.

On Tuesday night, it's going to get real cold. Leave it set for 70 and watch it.
Does the fan speed go up and down?
Does the system go into very low speed when the room goes slightly above 70??
Those would be good signs.. But, if the unit runs a high power and stays there, never slowing down.
That means, you system isn't up to the task. (Undersized or defective).
Or, the outside temperature is dropping so fast, the system can't keep up. (Undersized or defective)

Xringer,

Thanks for the information. Downstair we have 1060 square feet, we do not heat the upstairs. I'm of the opinion the heat pump fan runs at a constant speed when the temperature drops (if my memory serves me well?). I will have to confirm this. Again, thanks for all your help, I really appreicate it.

Poleikleng

[Xringer]

Originally Posted by poleikleng

Xringer,

The 1.5-ton unit does not have a defrost LED (correction, the units operation indicator lamp will flash during automatic defrosting mode). We have experienced the defrost cycle and as you mentioned during the cycle it does get cool.

How are you planning the upcoming cold spell? Will you turn on your oil furnace to a set temperature and also run your heat pumps?

Poleikleng

I've been thinking, Maybe running two units will make enough heat to
keep the oil burned from turning on.. Wishful thinking maybe?


My other idea is to plug in a couple of space heaters, and set them to come on at 65F..
While the Sanyos will be set for 19C (66.2F).
At about 4,000 BTUh each, they won't keep the house warm, but they might keep it from getting really cold..

And of course, I could set the oil burner to trigger at 63F !