How To Install a Ground Source Heat Pump

despite all the evidence of global warming for those of us living in the uk these islands can still feel like a pretty cold and inhospitable place for a great deal of a year and for that reason there are many people that would dismiss the idea of using solar energy to heat their homes but there is technology that makes this possible and that technology is called a ground source heat pump now the sun shines every day in one form or another whether it's cloudy or not and when the sun shines valuable solar energy is stored in the ground and getting that heat out of the ground and into our homes requires a very simple bit of technology now another myth is that you need acres of ground in order to make use of ground source heat technology but this isn't true there are different systems to suit different locations and even if you've just got a modest garden you can use a system which will make use of that heat now i must just emphasize that this is ground source heat and not geothermal energy so forget the hot springs in iceland and all that sort of thing this is just using the sun's rays which are stored in the ground as heat to heat your home so how do we get all that useful heat from the ground into our homes well the heart of a system is a heat pump now this transfers heat from the ground collector through the heat pump through some pipes into a thermal store in our home and then onto our radiators or under floor heating now you'd be right to think that this requires energy in itself to pump that fluid around but the good news is that for every unit of electricity that you put into the system you get four units of heat out so it does have a very cost effective ratio in the uk the most popular method of heat extraction is through horizontal collectors this continuous loop of pipe work is buried one meter under the ground and roughly speaking you would need the collectors to cover approximately two to two and a half times the total amount of floor space of your home [Music] if space is more limited a compact collector either in a horizontal or a vertical position can be buried in a series of trenches [Music] for the borehole method of collection a specialist contractor will be required to bury a pipe up to a depth of 200 meters this method of heat collection is more suitable for ground which contains a higher proportion of rock and stone [Music] [Applause] [Music] now after just two days into the job the guys have been blessed with a bit of good weather and they're getting on very well they're already at the stage where they're starting to backfill the trenches in the first pit you can see where the compact collector has been laid and that's being backfilled the brickwork at the end by the way is really nothing to do with a job it's because this is a showcase project and they want to leave a small area open so people can see what's involved but normally the ground would go back there's no brickwork or anything like that and you wouldn't even know it was there now that's one system the compact collector but if you've got the room the other way of doing it is to use a continuous trench which in this case just zigzags up down the paddock and this is just laid with a single pipe now this is the cheapest and easiest option but if you haven't got room for the compact collector and you haven't got room for the trench there is a third option of just drilling a borehole now this is the trench that contains the flow and return pipe it's collected the heat from the ground source collector and it's taking it through to the house and you'll notice that this pipe is insulated that's done to stop that pipe losing its heat as it goes towards the house and also to stop it transferring into the return pipe which is running back at a lot colder temperature and the return pipe is also insulated because in some circumstances it could freeze the ground now this is the point where the pipes come back from the ground source collectors and enter the house they're going into the boiler room and the pipes have been put on the test of four bar for seven hours to make sure there's absolutely no leaks in them and then they're going to be connected to these pipes here with some elbows and fed through to the hot water system now you notice that there's also an oil feed for the boiler this is an existing boiler and it's got to be kept because this is an old house it's badly insulated it doesn't have underfloor heating and that's there just as a backup for very extreme weather you know the coldest days but if you've got a new house if it's well insulated and you've got underfloor heating you wouldn't even need the boiler [Music] because heat pumps are so efficient the water actually returns to the ground source collectors at maybe minus two or three degrees centigrade and of course this is below freezing and to prevent that freezing we add a 30 solution of glycol antifreeze this house already has a couple of solar panels on the roof which are used to provide hot water and because it's having a ground source heat pump doesn't mean that these solar panels become redundant because they can be coupled in with the system through a dual coil cylinder while the work's underway the solar panels have just been temporarily covered up just to prevent them from producing too much heat while the system is decoupled [Music] the trench is dug and the pipe's in and it's all been tested and proved to be sound so now the ground can go back in just to be on the safe side in case there's any sharp stones or anything like that they're just going to put a layer of sharp sand over the pipe [Music] even though it is possible for this ground source heat pump to produce temperature to up to 65 degrees centigrade realistically when we're sizing the heating system we need to work on 45 degrees centigrade flow temperature with a 5 degree centigrade drop between the flow and return now this has implications when you're sizing radiators if the system has already been installed and designed to work with a boiler you need to think about increasing the radiator sizes by about 20 percent the other alternative is that you can use fan coil heaters or the better alternative if you can manage it is to fit underfloor heating now this is perfectly possible in new possible in bui but you can use a mix of these systems well it's now a few weeks later and we've returned to the scene to see how the system is working and as you can see miraculously the summer has now arrived and as far as the field goes it's all settling in pretty well you'd hardly know it been dug up apart from the two inspection hatches which have been left so that people can examine the system and have a look at the underground pipes so that's the ground source collectors grabbing all that lovely free heat now let's go and see what the heat pump does with it in this house the heat pump and all the associated plumbing is located in a boiler room and this is also being used as a demonstration area but you don't actually need a boiler room to have a heat pump these heavily insulated pipes are being fed in from the two different ground source collector systems and they're twinned together and then taken around into the heat pump itself now if i just sneak my fingers underneath the insulation here and feel the temperature of that pipe you wouldn't even notice hot it doesn't feel like there's any hot water coming from the ground at all but once it's been through the heat pump and that heat is extracted the water that comes out of the heat pump is very hot indeed i can only keep my hand on there for a few seconds now that hot water is being fed into the cylinder to provide hot water for the whole house so there's plenty of water there for baths and showers and everything but also the water is being fed across into this accumulator now this provides hot water for the central heating system but in the summer when that's not required in this case a diverter valve has been fitted so that that water is then diverted through to heat the swimming pool now there's one further addition to this system which is the solar heating this is the solar system it's got a pump and a control system and it measures the temperature in the cylinder and also measures the temperature of the solar panel on the roof and if the temperature of the solar panel is hotter than the water in the cylinder it will pump heat to the cylinder the sun is the most powerful energy source that this planet has and at the moment nearly all that energy goes to waste if we're going to make a serious effort to cut co2 emissions and provide heat for our homes in the future we have to start harnessing this energy by investing in renewable energy technology [Music] you

Channel: Skill Builder

Views: 97,702

Keywords: ground source heat pumps, low carbon energy, renewable sources, Greenstore LECP, Worcester Bosch Heat Pumps, ground source heat pump, renewable energy, geothermal energy

Id: qmWRN3Ob1Po

Length: 11min 0sec (660 seconds)

Published: Wed Jan 05 2022