Dream heat pumps.

[Worcester]

Sorry guys can't really help without knowing how it's all been plumbed in !!

Multiple heat sources, as always buffer tank, / low loss headers. Flow rate always a killer with Heat pumps - whats the minumum allowed l/min?

We ALWAYS install, in line 30µm (micron) strainers and flow gauges in heat pump systems.

Had a call out not so long ago to a 'self install' - retrofitted and not flushed, he was getting low flow rate failures every 24 nours becasue the filter was blocking up every 24 hours!! - without the filter he'd have completely b**g**d the hex (ps. is that ** allowed any more Croppie? )

However I would have though that the Dream should have some kind of autodefrost cycle .. (usually steals heat from the buffer or heating system)

 

[efficiencyman]

Yes, the dream units use their own 4 way valve where the parameters can be adjusted or set as per default. The auto defrost cycle including duration time & temps are ingeniously configured to use its own "generated" heat (hot gas injection) to self defrost ice on the evaporator (does NOT steal from buffer or heating system) or as some do - NOT via an element which is not included in the COP rating.

The dream units use well proven Mitsubishi, Toshiba or (as in mine) a Sanyo compressor, the micro processor control is also a well developed design which I was easily able to relocate the remote unit inside my house next to my heating controls.

 

[Nostrum]

It looks the same as the grant unit to be honest. Does it have weather compensation and an inverter driven compressor? I would like to see the instruction manual but can't find it. What's the warranty?

 

[BobsDream]

Thanks for the reply E-man and all. My systen has two pumps inline, one near the heat pump and one mid system. I added the second pump when I installed the powerful outdoor wood burner and it has always worked really well, as does the heat pump in heating mode.
I flushed the system well as I wanted to add some expensive anti-freeze and I installed a strainer filter. After a few weeks running the heat pump the filter is clean.
I expect it to ice up in certain conditions and I expect the auto defrost to work too.
The auto defrost uses heat from the system, by going into cooling mode, to warm and thaw the coils but mine was not working. I was advised to manually put it into cooling mode and this is when the error code PP06 appears and the machine shuts down. PP06 = water outlet and inlet temp difference overlarge protection. You can actually see the outlet temp reduce rapidly until the code appears. The powers that be in China say the water flow is too low and the temp difference should only be around 7 degrees or so.
E-man, are you able to put yours into cooling mode manually to see what happens?
I'm waiting for some fittings and then I'm going to rig up a test buffer tank with unrestricted flow to see if the cooling mode works. If it does I would consider installing a buffer tank next to the heat pump with big bore (28mm) pipes.
Nostrum, one year warranty!
Cheers
bob

 

[efficiencyman]

I fitted my own weather optomiser control wire directly into the provided link on main HP PCB.
You won`t find an inverter driven compressor at a dream price of £1500 for a 15 Kw unit.
High spec & manual on their web site. Don`t want to be accused of spam, easy to find.
Normal 12 months warranty but I have been impressed with Dreams after sales service and they sent parts by same day carrier free of charge after my 12 months that speaks of good reputation to me. Better than I have had from big named brands.

 

[Ermintrude]

How big is unit?

 

[efficiencyman]

My 15 Kw says on manual 111cm x 46cm x 68 high shipping weight 98 Kgs
requires water flow rate of 2.2 M3 per hour through 3/4" BSP.
It has a Sanyo rotary compressor COP of 4.3 @ 6 Degs C to water temp of 40 Degs C

 

[Whyme]

this is one of the most interesting threads ive been reading. you all lost me about post 5 but im sticking with it.:thinking:

 

[efficiencyman]

Why are you lost i ? It`s at least 80 year old technology (Refrigeration) brought upto date by transfering heat from outside air to my cosy indoors. The secret is keeping the efficiency up above 2.5 COP (Coeficient Of Performance) if you allow it work at lower values you won`t save much at all. By using as a hybrid if ambient temps go below say about 4 Degs it may Ice up from our high humidity jet stream weather. A Heat Pump will need defrosting this costs energy that won`t heat my house so I don`t let it make ice by swapping over to my A rated boiler which costs me about 10 % to 20 % depending how long I have a cold spell for. As that`s may be only 30 days in 365 that translates into a massive saving on my gas bill. Pong me with a bigger leccy bill YES and I will ping you the pay off a COP of 3,4 or 5 which pays off the fact that Leccy is more pricey than Gas. I can explain more ---- it`s getting late more Monday ? Are you still lost or catching up ?

 

[Whyme]

Haha yes i understand the fridgy bit but catching up on the tech..bring on monday i say.

 

[efficiencyman]

How can I help ? What is your hang up ? Explain in full what your need is ? It`s really a simple principle of obtaining heat from a cheaper source ( AIR ) in my case, in the most economic way.

 

[Whyme]

been browsing the net and am kinda up to speed. cheers for the offer of help getting my head round it. looks impressive especially as a hybrid system (when needed).ive never fit any or worked on any so was a bit lost back then. i'll say it again, a good interesting thread.:yes:

 

[Worcester]

Simples really, you have two heat sources, one (the Air Source Heat Pump ASHP) is efficient so long as air temp above 5°C outside, so when it gets below that a simple control box based around a frost stat calls for heat from a traditional oil/gas boiler. - Just need to make sure of the hysterisis of the outside stat as you don't want the system cutting in / out every few minutes, so go for at least a 3°C temperature change before switching back to the Air Source Heat Pump - say off at 4°C and back on at 7°C.

 

[josalsam]

Hi,
I am a retired refrigeration engineer: I bought a Dream 5kw air source Heat pump for an outside pool. When I bought it I will say they were very helpful and sent me a full spec on operating pressures etc. In their advert it states they should last 20 years, 'don't believe it'. This heat pump has been outside for two and a half years, it is covered to protect it from the elements in the winter months. When I started it up for this years season 2014 I noticed frosting back and no heat output, I quickly found the cause being the condenser fan fouling the housing. This was caused by the fan motor bracket completely rusting through where it was connected to the units base. A simple job if you can get a new bracket. I rang a person called VJ at Dream Heat pumps for a replacement, he told me they do not hold them in stock but he could get one by Autumn. Its now mid may and waiting until the end of the summer until I can get a new bracket is not on.
This VJ advised I go to another heat pump supplier 'Duratech' and try to get one from them as they are very similar. In a nutshell dream heat pumps are cheap and cheerful, there is a saying " you only get what you pay for" in this instance very true. This company's response to my problem beggars belief, why couldn't this VJ have tried to source a new bracket for me? In the meantime I will have to try and try some old contacts in the trade for help, something I should not have to do if Dream Heat Pumps 'World of Bargains Ltd' had a good after sale service. I would not recommend this Company or its Dream Heat Pumps. Again, I say " you only get what you pay for".

 

[Worcester]

They are a box shifting sales organisation, I would be astonished if they stocked any spares at all. They also flog hot tubs and all sorts of other stuff.
Requested a bunch of technical info and only got installation manual, looking for outputs below 15° air non existant! Mind you they are cheap!! (very Cheap)

 

[kris]

Simples really, you have two heat sources, one (the Air Source Heat Pump ASHP) is efficient so long as air temp above 5°C outside, so when it gets below that a simple control box based around a frost stat calls for heat from a traditional oil/gas boiler. - Just need to make sure of the hysterisis of the outside stat as you don't want the system cutting in / out every few minutes, so go for at least a 3°C temperature change before switching back to the Air Source Heat Pump - say off at 4°C and back on at 7°C.

Just remember guys anythings easy when you understand how it works but at the start of learning about anything its not always simple , just a thought eh whyme

 

[kris]

But very interesting , im like whyme if not done anything on AC although later this year ive my air source , ground source and solar thermal to do,

 

[happyflyer]

But very interesting , im like whyme if not done anything on AC although later this year ive my air source , ground source and solar thermal to do,

Kris,

A bit of a waste of time up there, Scotland, solid rock and freezing most the time, solar thermal, well maybe now and then.....:dizzy2::cool3::sunny:

 

[kris]

Cheers happy, air source can only really be used on its own on a new build up here which is fully insulated , on an existing building need secondary heat source but i dare say thats all over aswell eh, but i wouldnt fancy doin a bore whole in the granite city, need a mighty drill for that happy ,

 

[Worcester]

Would have thought nice cosy log burners or pellet burners (aka biomass) ideal for the frozen off-grid wastes up there

 

[Dream owner]

Hi all I have a dream heat pump on my swimming pool 15 kW and to be honest it struggles to get to over the 29 degrees and now seems to have given up heating, I called dream ( who only deal through the e mail or you can leave a phone message and the may call you back after 3 days ( trick to this is keep calling every 5 mins and fill up their answer phone system and you get a call back after 2-3 hours) but when you explain your problem and the fact that the instructions are translated from chinesse so don't make sence . They can't help you as they don't have a tech dept and told me to first press one button repeatedly and if that Didn't do the trick to call out an engineer ( but they didn't know anyone in the kent area and told me to go on google) so I think the cus service is appalinng,in house knowledge is poor,the pumps are from China,they don't have tosiba com pressures as the last time I looked they came from Japan even with the telesales guy trying to convince me otherwise, and would i recommend them yes only to the tax man or an ex wife who took the house and the pool . Anyone know of a good heater foe a swimming pool

 

[Nostrum]

Perhaps try a quality heat pump instead of one of these heaps?

 

[Unregistered]

Hi, I bought and installed a Dream 12.5kw last year but cant make head nor tail of the settings in the handbook (nor can 2 local plumbers or a computer expert) so i have to go outside to turn it on and off! It works well in default mode and i am happy with it but would love to be able to programme it! Email me at xxxxx if you can help please!

 

[Plumbstar Tom]

Hi please register and start a new thread for responses to your query