Bornagain

The submission was done by the Heat Pump installer, the only thing they were concerned about was the design of the UFH, I dug out the original design document which demonstrated that the UFH had much greater capacity than the calculated overall heat demand and they were happy. They applied for the grant without any drama.

We have UFH downstairs and no heating at all upstairs. We got the £7500 grant last year when an Aerotherm was installed.

The house is ICF with a wall u value of 0.15, windows and doors are all triple glazed u value of 1.0, the floor slab is on top of 300mm of EPS and there is over 600mm of insulation in the loft, we also have an MVHR system. The only heating is UFH in the downstairs floor slab, we have no heating upstairs. Heat loss is around 2kw @ -3c. 2kw x 24 hrs =48kwhrs, a 5 kw heat pump running for 7 hrs overnight generates 35kwhr, however when the weather is really cold we sometimes run the heat pump during the day powering it with PV. We have a humongous 500 litre thermal store, if it needed replacing it would be swapped to around 350 litre dhw cylinder. We have 7.74 kw of PV and 14kwhr of battery. We have had the battery through 4 complete winters and have never run out of charge, the only times we have come close have been Christmas days with no sun, this is because the house is full and we do a lot of cooking with two ovens running for hours. We have a 3.68kw grid tied inverter connected to the original FiT PV system plus another 4.4kw inverter connected to the battery and MPPTs In our experience the maximum instantaneous demand for electricity is very very rarely above 5kw, we are on an E7 tariff and have only bought 44kwhrs of peak electricity in the last twelve months. If you want to talk then drop me a message and I’ll give you a ring.

We live in our extremely well insulated 200m2 self build that we did in 2011. Heating is by a 5 KW Vaillant Heat Pump that runs for 7 hrs per night on an economy 7 tariff. When we get extremely cold weather, perhaps 5 days per year, it is typically very sunny and we also run the heat pump on daytime solar PV to consume the excess production. The downstairs temperature is always in the range 20.5-21c and it’s around 19c in the unheated bedrooms. Heat pumps most certainly can work in a modern house without needing a battery.

As an afterthought, our stairwell is very open and this allows heat from downstairs to make its way into the upstairs rooms, we have to keep the bedroom doors closed to keep them cool. If your stairwell is very narrow then there is a possibility that the heat from downstairs won’t be able to make its way upstairs, it’s worth thinking about.

Our self build is heading towards passiv haus, wall u value=0.15, roof=0.1, windows/doors=1.0, MVHR etc etc. We heat the house with UFH downstairs into a very thick slab, we have no heating whatsoever upstairs. if we built again, we would do the same, there is absolutely no need unless you want a very warm bathroom - we don’t.

We live in our 200m2 self build that we built in 2011, it’s ICF with triple glazing and all the usual bells and whistles. For the first 14 yrs we heated the downstairs UFH using E7 electricity, last September we had a Vaillant 5kw ASHP fitted. We have no heating upstairs. It runs for 7 hrs per night on E7 electricity, the house is maintained in around 20.5-21 c downstairs and it’s around 19c in the bedrooms. On the really cold days a week or so ago when the temperature was less than zero all day and as low as -8c at night we ran the heat pump during the day using power generated by the PV system as it was very sunny. The annual operating cost is next to nothing, the annual maintenance will cost more than the electricity. The installation cost the BUS grant and we had to pay about £900 on top, we used a local(ish) firm recommend by Vaillant who are also Heat Geek Elite installers. We couldn’t be happier with our install, and I can’t really see how it could work any better - it does exactly what it says on the tin.

Our 15 yr old self build doesn’t have any heating upstairs. The walls are ICF with a U value of 0.15, the windows and doors are triple glazed, we have shed loads of insulation under the ground floor and in the loft, we really went to town with the insulation. Downstairs is heated by an ASHP connected to UFH running on openloop All the downstairs rooms and the landing are at the same temperature (more or less) We keep the bedroom doors shut to keep them a couple of degrees cooler than the rest of the house. During winter we dry washing on clothes maidens, it typically takes a day or so to dry the washing, presumably the MVHR helps. If we were building again, I definitely wouldn’t bother putting heating upstairs.

We live in our self build that we did in 2011, the house is ICF with all the normal bells and whistles. It has UFH downstairs with no heating upstairs, the UFH being powered by E7 electricity. This summer we have taken advantage of the BUS and have had an ASHP fitted which heats the existing UFH and thermal store which then provides DHW. We had three firms in to provide quotes and all of them were happy that we would be eligible for the BUS grant without adding any heating upstairs, the work has been carried out and the grant has been paid to the firm. The slab that our UFH heats is a combination of 100mm of concrete and around 170mm of screed, this all sit on top of 300mm of EPS - we have a very low heat curve and the heating is working with a COP in excess of 5, there is almost no cycling.

1) The intention was to have 100mm of screed, but complications with ceiling heights, door & window heights meant it was simpler to just have a thicker screed. 2) We did our build in 2011 and at that time the typical approach seemed to be to have the UFH pipes in the screed, so that’s what we did.

Ignore them. Our house from the ground up consists of hardcore, blinding,damp proof membrane, 300mm of EPS, 100mm thick concrete slab then finally 170mm of screed which included UFH pies. For all practical purposes our floor is a 270mm thick thermal store. It takes a lot of energy to heat it up but it then takes ages to cool down, this allows us to heat it up using economy 7 electricity and the heat easily lasts through the day. If we were building again I would do exactly the same. The only downside is that it took a long time to cure and hence delays tiling at the time you are very keen to get into the house.

Without wishing to bore anybody, there were a number of issues with our fibre install that meant that OR staff were not allowed to preform a lot of the work due to their company H&S procedures, they were more than happy for me to do everything under their direct supervision, the only thing that they did was make up the fibre joint and fix the internal box of tricks to the wall. I found the OR staff to be friendly and flexible and keen to get on with the task. They were extremely cautious when they turned up to do our install so I rather suspect that they were expecting some kind of audit - anybody who has worked for a big business has been in their position.

Faced with a problem like this, I would make a rectangular timber frame with the same length and width as the intended caravan, gather a couple of mates to help and then pretent to be the 4x4. You will quickly establish if it will be possible to move it into the desired spot; the activity is quick, cheap and you can be very confident that you have the correct answer.

I have one of these units and the App allows you to plan for different temperatures, at different times, on different days. It works very well and I can't imagine how it could be more flexible.

Ours are internally beaded, it does indeed give a very sleek look from the outside. We have never needed support so I can't comment on their aftercare.