PV immersion heater proportional control

[Worcester]

echase on solution for you:
Pumped mains pressure (i.e permanently circulating) hot hater is a commion feature in premises with long hot water pipe runs and is used a lot of commerical premises, ideally of course going through a thermal store, that way hot water is always hot instantaneously.You need effectively a 'ring main' of hot water pipes to do this of course.

 

[CBR600]

Anyone had a look at iBoost? Seems competitively priced and communication is wireless so no issues if the immersion is not on it's own circuit.

Solar iBoost - Free Hot Water From Your PV Array

Before you ask, no I don't work for Marlec or have any interest in the product!

 

[danesol]

Anyone had a look at iBoost? Seems competitively priced and communication is wireless so no issues if the immersion is not on it's own circuit.

Solar iBoost - Free Hot Water From Your PV Array

Before you ask, no I don't work for Marlec or have any interest in the product!

When you say "competitively priced".... how much is it as it doesnt seem to state on website ???? :angel_smile:

 

[CBR600]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

 

[echase]

echase on solution for you:
Pumped mains pressure (i.e permanently circulating) hot water is a commion feature in premises with long hot water pipe runs and is used a lot of commerical premises, ideally of course going through a thermal store, that way hot water is always hot instantaneously.You need effectively a 'ring main' of hot water pipes to do this of course.

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

 

[danesol]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

and how much is that ???

 

[The Solar King]

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

Grundfos do a range of secondary circulation pumps starting at around £120.00. I have used a basic one in our own house in conjunction with a Horstmann Channelplus H47XL four channel timer. (CH, HW, UFH, & secondary circulation). It is timed to come on when hot water is mainly used. Every pipe is insulated to within an inch of its life. System monitoring shows we are loosing very little in terms of temperature drop on return to the tank. Absolute bliss to turn on the shower and get straight in.

 

[Worcester]

My last house had such a pumped system but it had been disconnected, presumably because of the heat losses from constantly circulating it in uninsulated pipes mostly buried in the concrete floor. Running its standard CH type pump all the time to circulate it can’t have been very energy efficient either.

I could do it on this house for the annex only, but would need a small pump and/or a control system to keep the losses down, e.g. turn it off when no occupancy/movement detected. Or detect the pressure drop when tap turned on and then starting the pump like caravans use. If it were a CH pump on full speed it would then pump the hot water to taps pretty quickly. Are there standard ways to control this?

Not circulating it would give no benefit of a 'standard' mains pressure combi or unvented system. Yes there are standard pressure drop controllers - think power shower. As for movement sensors triggering a pump, just use a normal PIR linked up to a contactor. Simple inexpensiive Din rail mounted contactors form Chint NO or NC. However see The Solar King's post you do need to insulate well.

We picked this up on a refurb project we visitied the other day that also had pumped hot water - no insulation at all, I pointed it out to the owner who immediately got the plumber back on site

 

[danesol]

danesol, has a trade price that is less that Immersun & Solic 200.

The key benefit for me is the wireless connection.

How much was that again............. :tounge_smile:

 

[provr6]

Has anyone tried one of these? THE RENEWABLE ENERGY SHOP - reuk.co.uk

For 30 boof looks worth a try. Sure it dosen't look as well built as the commercial products but if it works could be worth a punt.

Tempted myself

 

[CBR600]

Danesol, as is often stated on these threads, announcing trade prices is not very helpful; we all need to make a living. However I can see that Immersun is being offered on-line fitted for £495 including VAT and I am sure you could get the iBoost fitted for a similar price.

 

[danesol]

Danesol, as is often stated on these threads, announcing trade prices is not very helpful; we all need to make a living. However I can see that Immersun is being offered on-line fitted for £495 including VAT and I am sure you could get the iBoost fitted for a similar price.

That is very true CBR600 and the way it should be especially for trade only sites, however this is an "open forum" so threads which contain both retail & trade pricing could get confusing for some.

I noticed you only made comparison to the Immersun & Solic 200 as a trade price fit which is fair enough, however when members viewing on, see this in comparison to the supply of devices like the SolarImmersion and i2 at £ 229 and £ 199 delivered respectfully which I may add are just as good if NOT better - to me that can more of a negative effect for good PV Installers & Electricians alike as it shows to propective clientèle they are either been ripped off or the units themselves are way way too dear, as any competent electrician/installer should be able to fit anyone of these devices between 30 to 60mins and at £ 75 p/hr say - that ain't much ontop of £ 229 for Solar Immersion giving a top estimated fitted price of say £ 304, a saving therefore of £ 191 on the likes of the Immersun, Solic200 and the one you are mentioning - iBoost

 

[CBR600]

I am not quite sure how I am being pulled into a discussion about pricing, my original question was about iBoost and if anyone had any experience with it so perhaps we can discuss that. If you have I would be very interested to to hear! Alternatively, if you have experience of fitting another device that communicates wirelessly I would be very interested to hear about that too as this is my primary interest in this device.

 

[danesol]

I am not quite sure how I am being pulled into a discussion about pricing, my original question was about iBoost and if anyone had any experience with it so perhaps we can discuss that. If you have I would be very interested to to hear! Alternatively, if you have experience of fitting another device that communicates wirelessly I would be very interested to hear about that too as this is my primary interest in this device.

The very reason you are been pulled into a discussion on pricing is that is so important to most, there's no point IMO paying more if unit.A can do exactly what unit.B can do for £200 less.............. otherwise you just hope the more expensive item comes with a 25yr warranty

IMO, there is very little difference from the user prospective, in how all these different makes & models undertake their primary task - divert excess electric proportionally to your existing Immersion Heater element. However you may want to pay a little more for say reporting and having a secondary relay as standard or linking into to other products such as the Elios Monitoring system.........

I did want a wifi device initially, but I eventually decided against it due to battery longevity and associated issues and just did the donkey work necessary to pull a cat5 cable through to extend the CT sensor.

However, after all that the iBoost is a nice looking device if you are going to have it on show, unlike me with mine in the airing cupboard .................

 

[Worcester]

Or these 3 Immersuns powering 4 x 4.5kW = 18kW of 3 phase immersion mounted above a 2500 ltr thermal store in the basement of biomass heated and PV powered building