Category: heat pump (Page 2 of 4)

The ground source heat pump is still running!

February 24, 2014 / stephen

After a rather “bumpy” start, I am glad to report that the ground source heat pump is still running! It is providing all of the heating and hot water in the house since the 12th Feb. This is much to our relief.

We still have some way to go in terms of getting all the room thermostats operational – the ones in the new extension have yet to be powered up. We also have builders/decorators on site and it is difficult to keep the windows and doors closed all of the time. So it is very likely that we will see some more improvements over the coming months.

Even so, the internal temperature seems to be doing well (even without the log burners going!). However, it has yet to be fully tested in the real Yorkshire weather. Today, it is a rather barmy 10C.

The ground source heat pump was repaired on the 12th Feb. You can see quite clearly the impact that this has had on the internal temperature of the house. The temperature gauge is in the downstairs bedroom were the temperature is set to 18C. It was also on the internal window cill where the sun (yes, it does happen occasionally in Yorkshire!) gets to it!

The ground source heat pump is still working!!

February 13, 2014 / stephen

As well as generating heat for the house, we also now have a full tank of hot water.

Although it is going to take a few days to get the property up to full temperature, we haven’t done too badly in the last 20 hours or so. Below is an update on the internal temperature graph from our weather station.

Inside temperature after the ground source heat pump was turned on about 4pm yesterday afternoon.

Update on the ground source heat pump

February 12, 2014 / stephen

It looks as if the problem with the ground source heat pump has finally been fixed (although it would appear that there was no problem to be fixed). It is going to take a few days for the house to get up to temperature, but at least it is a start.

The heat pump has been throwing LP (Low Pressure) alerts for the past couple of weeks. The ground loops were flushed. But there was no air in the system. All of the strainers on the ground loops were checked. Again, no problem. The circulation pump for the ground loops was replaced. But the same problem persisted. The software on the heat pump was updated. No difference.

The Nibe engineer spent 5 hours on site and finally struck on the idea that the temperature of internal underfloor heating was too low. Apparently, there needs to be a significant temperature difference between the ground loops and the underfloor heating otherwise the low temperature in the underfloor heating will reduce the temperature (and thus the pressure) on the ground loops.

The answer appears to be to use the internal immersion heater to raise the temperature of the underfloor heating. Then the ground source heat pump could be engaged and, voila, it all works as it should.

We restarted the heat pump about 6 hours ago (around 4pm this afternoon) after engaging the immersion heater for a while. The good news is that it is still running (and generating heat). Fingers crossed.

Here’s the graph for the internal temperature from our weather station. You can see where the heat pump was turned on around 4pm. Hopefully, the graph overnight will look just as good. Fingers crossed.

Problems with the heat pump

February 9, 2014 / stephen

The ground source heat pump worked well for about 2 weeks and then started shutting down with a low pressure alarm. This is normally due to an issue with circulation of fluid in the ground loops. Last Friday, we had to give up and turn the unit off altogether. We have now been without heating and hot water for the last week.

Initially, it was thought that it was dirt in the system, but there was no dirt in any of the strainers and the system was flushed to prove the point. Then it was thought that it was the pump that pumps the antifreeze around the ground loops. This was replaced, but the fault still persisted.

Neither the installer or NuHeat have been able to resolve the problem despite their best efforts. This issue now resides with Nibe who are the manufacturer of the ground source heat pump unit itself. Unfortunately, this means further delays as we have to wait for an appointment for the engineer to come out.

When the heat pump is back up and working, it will take 2-3 days at least for the property to get back up to full temperature. We are just gratefully that it hasn’t been too cold yet this winter!

Ground source heat pump

January 19, 2014 / stephen

We finally got the ground source heat pump up and running on Thursday. The commissioning took most of the day with the majority of the time taken up getting the antifreeze into the ground loops (the pipes that run underneath the field). There is around 125 gallons of antifreeze (glycol) in the 1800m of ground loops.

The ground source heat pump was powered up around 4pm on Thursday. It took around an hour to heat up the hot water tank (500l). Once the hot water tank was up to temperature, we turned on the underfloor heating. It will probably take until next week before the building is up to full temperature (21c), but the building felt warmer the next morning.

With 125 gallons of anti-freeze installed in the ground loops, we have around 30-35 gallons left over. Not sure what to do with this. Maybe ebay?

Apparently this anti freeze will detriorate if left in the sun for a significant period of time. If you are going to store it outdoors, do make sure that it is under cover.

Problems installing the heat pump

December 24, 2013 / stephen

The ground source heat pump (and associated paraphernalia) was delivered last Monday. Over a week later and we are struggling to get it working properly.

While it only took 2-3 days to get all of the pipework in place, it has taken the same amount of time again to try to get the air out of the system. If there is an airlock in the ground loops, the fluid will not circulate into the pipework under the field and we won’t be able to extract any heat.

Through rather convoluted process, we managed to get all the air out of the system. This included flushing the ground loops with water to drive the air out, venting the ground loop manifolds and running the ground loop pump with no pressure (allowing the air to work its way out of the system). Once the air was out of the system, we checked the strainer only to find that we had picked up a lot of dirt while flushing the system. I guess this is what strainers are for!

With the strainer removed, you can see the amount of grot that has been captured while the system has been flushed. We thought that this would have been the cause of the “low pressure” alert on the heat pump, but sadly not (or at least, not the entire cause).

Our plan was to run the system with water in the ground loops rather than a mixture of water and anti-freeze. This seems to be our next problem – the temperature of the water is reduced to a point where it will freeze in the heat pump without anti-freeze. Unfortunately to get the anti-freeze into the system, we need to hire a pump. In the meantime, the heat pump displays a “low pressure” alert after 20-30 seconds of the compressor starting. Due to the Christmas break this is going to have to wait until the end of the week.

Top marks to Neil and Ricky from Sol-Air Renewables (www.solairrenewables.co.uk) who have really put some long hours in this week to try to get the heat pump up and running.

In the meantime, we are using the heat pump’s immersion heater to slowly raise the temperature of the water in the underfloor heating. We have put the heat pump into “floor drying mode” and this slowly raises the temperature over a two-week period. Even though the ground loops aren’t working yet, we will be able to dry out the floors.

Hopefully we will get some more progress towards the end of this week (most likely Friday).

The ground source heat pump is the fridge/freezer to camera right, the large round tank is a 500 litre hot water tank and the smaller tank is a 300 litre buffer tank (it stores excess hot water produced by the heat pump). Ricky has done a great job of installing all of the pipework. The guys installing the cast iron gutters at the weekend referred to it as “the engine room on the Titantic”. Mmmm. I might see the funny side of it once it is working!

Installing the ground source heat pump

December 18, 2013 / stephen

The ground source heat pump was delivered on Monday and we have spent the last couple of days getting it installed. Most of the pipework is now installed, however, there is probably another day’s worth of pipework to go. The electrician is due in tomorrow to start wiring it up.

We hope that the system will be up and running (although in a limited capacity) by the end of the week. This will mean that we should have heat in the building over the festive period. Because we have laid new concrete floors these need to be dried out – and slowly otherwise we risk them cracking. We also want to dry out all the wood (particularly the oak) very slowly – otherwise there is a risk that this will crack too.

As you can see from the photograph below, this kit takes up a lot of space. We have done the best job we can of reducing the amount of space it occupies (including installing a couple of steel beams to hold the tanks), but even so the utility room does look more like a plant room at the moment!

If you are planning on installing this kind of kit, it would be wise to ensure that you have enough space for it. Our house isn’t small and we are struggling to provide enough space. It needs significant planning well ahead of installation time. This isn’t an issue that the providers make particularly clear when selling the kit (surprise, surprise!).

The ground source heat pump (the unit that looks like a fridge/freezer) is a Nibe 1145. There is probably another day’s worth of pipework still to go in. These systems are complex and take up significant space – this is starting to look like a plant room!

Utility room

October 5, 2013 / stephen

The utility room is fairly big – 2.3m x 3.8m – but there is a lot of kit to go in here. Two cylinders for the ground source heat pump, under floor heating manifold, pump module and the ground source heat pump. The layout suggested by the ground source heat pump installer would have effectively converted the utility room into a plant room.

We realised early on that there was significant height in this part of the extension and therefore decided to raised the two cylinders up onto a platform so that the underfloor heating manifold and pump could be installed underneath them. This reduces the amount of space required in the utility room to install this kit.

The steels that will support the platform for the cylinders were installed this week.

There is a lot of kit to go into the uitlity room that relates to the ground source heat pump. By putting some steel beams into the utility room we can raise two of the water cylinders up and put additional kit underneath the cylinders.

Re-laying the top soil

September 11, 2013 / stephen

All of the ground loops for the ground source heat pump have been covered. The ground loops were pressurised to 1 bar when they were installed. And there are still pressurised to 1 bar after the soil has been put back. At least we know that none of the pipes have damaged while the soil has been reinstated.

We are going to re-lay the topsoil on those areas of the field away from the builder’s cabin and the house. We can then re-seed this part of the field and it will have the opportunity to the grass to grow before the winter sets in. I am guessing that we will reseed at least 1/3 of the field (around 450 sqm) in the next few days (weather permitting).

The view from the soil pile – we are relaying the top soil on the far part of the field.

We are going to be putting the topsoil back down on the area of the field away from the builder’s cabin and the house. We will relay the rest of the topsoil, once the building work is finished.

The subsoil has been tracked in and levelled. There are 1000m of pipe under this particular patch of the field.

Back filling the ground loops

September 9, 2013 / stephen

We have spent most of today back filling the land after installing the ground loops last week. We have installed 1800m of ground loops in the field adjacent to the house. This has been a mammoth task since it has involved removing all of the topsoil and subsoil from this field, installing the pipes and then back filling the field.

Today, the last of the pipes were covered up. Hopefully, we will not be seeing these again for a very long time. The pipework has been pressurised while we have been backfilling. If any of the pipes get damaged, the pressure would drop immediately. Fortunately, the pressure has remained exactly the same throughout.

I took some time lapse video of backfilling the field today. You will find it here on YouTube.

We have made some serious progress today on reducing the size of the spoil heap. All of the subsoil is back down.

This is probably the last we will see of the ground loops. Hopefully. Covered with light grey sand and then buried under the subsoil.