Grant HP290 Enable Cooling Support ✅

[glyn.hudson]

Despite what the manufacturer says the Grant HP290 actually supports cooling ‘out-of-the-box’!

Thanks to @LeeNuss for figuring this out, I followed his instructions and it works

Econext: Direct local control of Grant HP290 Econet replacement (Plum ecoMAX360i)

The work mode is already available in the integration - it’s exposed as preset modes on the climate entity for each circuit: Comfort = Day mode Eco = Night mode Schedule = Auto Boost isn’t supported by the HA integration yet - I’ll add that in. afaik the grant 290 does support cooling! There are a few things that need to be in place though: Cooling support needs to be enabled for the heatpump. Either in the HA integration or via the 0000 service menu → Main heat source → Cooling support C…

These steps are copied from @LeeNuss 'a post on the other thread

• Cooling support needs to be enabled for the heatpump via the 0000 service menu → Main heat source → Cooling support
• Circuit type must be set to either UFH or Fan Coil - radiator circuits don’t support cooling. (min cooling temp is 18C for UFH, ~7C for fan coil)
• Cooling needs to be enabled per circuit - each circuit has its own cooling enable switch
• Operating mode needs to be set to Summer, or set to Auto with the outdoor temp above the summer threshold

I’ve just tested this myself, here’s some screenshots of what these settings look like

If you do enable cooling, and you’re using our Emoncms monitoring, make sure to enable Cooling Auto detection in MyHeatpump app settings. If you don’t know how to do this, get in touch

Cooling flow temperature is set under Circuit ‘Fixed preset eater temp - cooling’, if you’re using radiators to stay above the dew point you probably don’t want to go lower than about 17-18C. If you know the temperature and humidity of the house, you can calculate dew point

WARNING: when using cooling with radiators, it’s important to keep the temperature above the dew point to avoid condensation on emitters in unlagged pipework. Condensation liquid can cause rust damage to your house.

From my testing, using radiators for cooling above the dew point provides an insignificant amount of cooling. Having a separate circuit with wall-mounted fan coils is probably the way to deliver proper cooling, although at that point maybe a cheap mini split would be easier?

I don’t have personal experience with UFH, but I’ve heard that it can be moderately effective, at least physiologically having a cool floor could feel nice!

Note: I don’t have any requirement for cooling myself, in North Wales it only gets above 25C for a couple of days each year. I was just testing this out of curiosity

[Galicia (Frank Smith)]

I have tried UFH cooling and it had a minor effect in my case. A few degrees in cooling a room. However, the floor is cool on bare feet, which can be nice. It’s also important to keep the floor temperature above the dew point to avoid condensation on the floor or any uninsulated piping.

[Cillian_Cahill]

Heat geek have a vid where the cool air sits above the floor, try a basic fan to mix it around the room.

[marcexec (Marc-Aurel Evers)]

I’m putting in a duct mounted heater/cooler for the MVHR for this reason: Vent-Matika Duct Mounted Cold Water Cooler Range – BPC Ventilation Store

[Johnmo]

Find it appalling that a lot of heat pumps sold in the UK have the cooling mode hidden or not readily available or worse still inhibited or you have to pay to get a widget to make it work

[Johnmo]

@marcexec

I’m putting in a duct mounted heater/cooler for the MVHR for this reason:

Be prepared for almost zero cooling effects from MVHR. Total flow rate and the effects of cooling are almost no existent.

[glyn.hudson]

@Johnmo

Find it appalling that a lot of heat pumps sold in the UK have the cooling mode hidden or not readily available or worse still inhibited or you have to pay to get a widget to make it work

Agree, the expensive Vaillant cooling enabling resistor is ridiculous

At least on the Grant HP290 you just turn on cooling setting! I actually think it’s wise the choice they made to not allow cooling with rads.

[Johnmo]

@glyn.hudson

At least on the Grant HP290 you just turn on cooling setting!

Interesting, I asked Grant specifically if the R290 supported cooling and they said no. So bought a Hiaer instead.

[glyn.hudson]

@Johnmo

Interesting, I asked Grant specifically if the R290 supported cooling and they said no. So bought a Hiaer instead.

I’ve no idea why they say this. Possibly, it’s a misconception about the BUS grant that cooling is not allowed. All the MCS documents that I’ve read permit the unit to do cooling as long as the system is designed and optimised primarily for heating.

[Johnmo]

This is the email I got from them, question was asked in Jan this year

Grant UK R290 heat pumps are suitable for heating applications only – cooling is not a configurable option. Furthermore, I am not aware of any Grant UK plans to investigate cooling options in the near future..

[glyn.hudson]

@Johnmo

Grant UK R290 heat pumps are suitable for heating applications only – cooling is not a configurable option. Furthermore, I am not aware of any Grant UK plans to investigate cooling options in the near future..

How strange. I’ve just seen that Grant has released a controller simulator webpage, the cooling option is clearly visible: Grant Smart Controller Navigation Tool

[Johnmo]

I did the installer training, and there dip switches within the unit, but the controller manual mentions nothing. So thought I better ask before I buy. Looks like they lost a sale.

[Cian (Cian Rooney)]

How have you found the Haier in terms of in setup, control?

[Mart]

Tried out cooling on the HP290. Great COP, terrible cooling ability with radiators as expected . Its a real shame there’s no easy way to utilise this feature to effectively cool.

[Johnmo]

I run fully single zone UFH in thick screed.

Cooling is super simple and runs well. Set to 15 degs it runs for hours and with great CoP.

Heating has been a little different, it is almost reluctant to cycle, so will do everything it can to keep running. Even if this means hunting around the set point, which can lower CoP from 6 to about 4.5 or lower.

Think the main issue is the algorithm to control seems to be optimised for radiators, the floor acts as huge buffer and return temp is almost too stable so heat pump does a control change doesn’t see the return temp shift it expects.

To counter this, my WC curve is almost flat, 26 to 28 degs. The I use a simple thermostat as a start, stop permission. Have set the controller to believe there is a buffer, this stabilised things (I don’t actually have a buffer). Mild day heat pump runs for a few hours and if it’s colder it just runs longer.

Today’s cooling run

A good running mild day

Another day with hunting

I think if I didn’t have great insight to what’s happening with the heat pump, the normal person would see a 4.6 CoP and think it’s running great and not knowing you get better 6+

[glyn.hudson]

Nice work, is this system on HPM?

[Johnmo]

It’s No 1 on 7 day stats, No 3 on 30 day, 90 day is catching up.

[glyn.hudson]

@Johnmo

It’s No 1 on 7 day stats, No 3 on 30 day, 90 day is catching up.

Great stuff: https://heatpumpmonitor.org/system/view?id=337

[LeeNuss (Linus Reitmayr)]

I’ve been running UFH cooling on the Grant R290 for a bit now. The controller for it is very basic and carries real condensation risk on UFH. A few quirks I’ve run into:

• HP won’t start at a dew-safe target temp. To kick it off you need a “dip” of the cooling-water target (~15-16 °C in my case). I haven’t figured out which parameter limits this – might be a hard-coded hysteresis of 5 or similar.
• The HP sometimes refuses to cool, probably due to cycling limits. HPStatusWorkMode then toggles between cooling ↔ standby every 10-30s.
• No dew protection at all. The HP will happily pull flow well below room dew point and sweat the UFH manifold and pipes.

To make it safe I built a cooling controller into the econext HA integration. It’s still a WIP, but I had it running through the heatwave without any condensation. It dips the cooling target to force-start a cooling cycle, then holds and monitors a dew-safe target while running, and force-stops before flow gets too close to dew. There are quite a few parameters to tweak for run-time and cycling – the sweet spot will vary by setup, so expect a bit of trial and error to find maximum cooling without risking condensation.

To try it: download version v0.2.0-beta.1 via HACS, then reconfigure the integration to enable cooling in options. Pick a dew-point sensor (required - thermal_comfort integration works well) and ideally a accurate flow sensor (I use the OpenEnergyMeter flow sensor). The README has the full walk-through.

Happy to have brave testers. Run with dry-run on to test it without any writes.

[Cian (Cian Rooney)]

Thanks @Johnmo great detail - appreciate it. Current house is single pipe from what I can gather (without ripping the place apart), usual poorish mass build 1980s semi in Dublin. Thinking of self install, as the Irish Govt grant scheme is restricted to houses at a certain energy rating to qualify (bureaucracy gone mad) and I can’t see me hitting that unfortunately - still investigating this though.