@bretix It was actually part of the RHI scheme so I got a rebate back for installing the metering and monitoring package - a bit of a no brainer for me.
This is the open source monitoring solution I was referring to before on heat geek that you may want to look into -
You will still need to purchase the sensors to capture the data being monitored.
Alternatively have a look at passiv systems they are the ones used as part of my install
@shapingstuff a secondary circulating pump will reduce the temp in your cylinder quite quickly and will be expensive to run if it's on all the time. You can use timers to help or maybe better is to install sensors in the bathrooms furthest away that triggers the pump to kick in once it detects someone has walked into the room.
Does anyone know the purpose of a volumiser tank in a heat pump system design. I have one installed based on the schematic attached below but have no idea what purpose it servers or whether it leads to an efficient design
Dow
My understanding is that the volumiser is added, as the name explains, to add water volume to the system. The purpose is to store heat energy for when the heat pump performs a defrost cycle.
To defrost the heat pump evaporator quickly, particularly when the outside air temperature is around or below zero, it is necessary to take heat energy from inside your home, in particular from the water within your central heating system. Larger heat pumps obviously require more heat energy to defrost, so will require a larger volume of water, which could be the reason a volumiser tank was installed in your system.
It has no detrimental effect and is certainly much better than installing a buffer tank, in fact it may help to reduce short cycling during warmer weather conditions.
Does anyone know the purpose of a volumiser tank in a heat pump system design. I have one installed based on the schematic attached below but have no idea what purpose it servers or whether it leads to an efficient design
Dow
My understanding is that the volumiser is added, as the name explains, to add water volume to the system. The purpose is to store heat energy for when the heat pump performs a defrost cycle.
To defrost the heat pump evaporator quickly, particularly when the outside air temperature is around or below zero, it is necessary to take heat energy from inside your home, in particular from the water within your central heating system. Larger heat pumps obviously require more heat energy to defrost, so will require a larger volume of water, which could be the reason a volumiser tank was installed in your system.
It has no detrimental effect and is certainly much better than installing a buffer tank, in fact it may help to reduce short cycling during warmer weather conditions.
The interesting words are in the last sentence as detailed below.
The low loss header is just one way, but hopefully it provides engineers with an installer-friendly solution to futureproof their heat pump installation.
@soniks I hadn't thought of sensors for when people are in the room - nice idea. I was going to time it but even then it means having it on quite a lot unnecessarily. I've got a shelly 1 on the way for the pump so I'll see what works best.
I found a supplier of the open source option but it is quite pricey at around 700 and not convinced there are that many adjustments I can make without more engineers.
@soniks that's really useful thank you. It was just put as a no if that's what the MMS system is on the heat loss survey. Then again it initially for an ecodan and I was told mitsubishi were paying people further incentives to have the monitoring. It then turned out the installers only had grants left!
On a side note it will be interesting if the govt will increase the RHI in line with inflation...
2 10kw Grant Aerona3
Heat loss calc 16.5 kw @ -2.8 degrees
4.32 PV
The Grant low loss header is a decent bit of kit, but Grant bizarrely don't put flow monitoring and adjustment gauge on primary and secondary circuits, only the primary side. That means you've no way of knowing if the LLH is balanced - the primary flow should = the secondary flow when all emitters or zones are calling for heating. Problems start when the secondary flow is higher than the primary, as cooler return water is then drawn into and mixed with the secondary flow. There's a small but unavoidable efficiency penalty when flow and return are hydraulically coupled, some heat will flow from high state to low state, even when the header is balanced. You've got the running cost of the secondary pump of course, but with ASHP retrofits the primary pump in the ASHP may not be man enough head to deliver adequate flow round 22 and 15mm pipework, so a secondary pump may be required regardless even on a single zone simple circuit. Grant Chofu primary pumps are quite decent capacity fixed speed/head units, but every Grant install features a secondary pump so they never get a chance to realise their potential.
Sorry if I'm hijacking this thread but it's really helped already!
My Grant ashp is at 45 flow. The temperature gauge for flow on the ufh is at 40. Is it normal to lose around 5 degrees? Ashp is in the garage and there is maybe about 10 meters of pipe. Is there some mixing that happens that will show on the temperature gauge?
Does anyone else have there ashp in the garage? I was wondering wether there is any benefit making an insulated cupboard for the tank and everything else. There is a lot of copper pipe around the tank that is not insulated and I'm guessing a lot of heat loss especially when below zero. Is that over kill?
@soniks that's really useful thank you. It was just put as a no if that's what the MMS system is on the heat loss survey. Then again it initially for an ecodan and I was told mitsubishi were paying people further incentives to have the monitoring. It then turned out the installers only had grants left!
On a side note it will be interesting if the govt will increase the RHI in line with inflation...
They will; it's in the contract:
Applications submitted before 1 April 2016 have their tariffs adjusted in line with the Retail Price Index (RPI).
Applications submitted on or after 1 April 2016 have their tariffs adjusted in line with the Consumer Price Index (CPI).
Sorry if I'm hijacking this thread but it's really helped already!
My Grant ashp is at 45 flow. The temperature gauge for flow on the ufh is at 40. Is it normal to lose around 5 degrees? Ashp is in the garage and there is maybe about 10 meters of pipe. Is there some mixing that happens that will show on the temperature gauge?
Does anyone else have there ashp in the garage? I was wondering wether there is any benefit making an insulated cupboard for the tank and everything else. There is a lot of copper pipe around the tank that is not insulated and I'm guessing a lot of heat loss especially when below zero. Is that over kill?
It is possible that the water being supplied to your UFH loops is being limited at 40C, to protect your flooring. It you only have UFH and no radiators then it should be possible to limit the LWT from your heat pump to 40C also. That should improve the efficiency of your ASHP.
