Tom & Derek the Worm is turning

The Worm is Turning.

Derek’s, Mobile just pinged, Tom asking him to ring him back when he can.

2 Hrs later:

Tom, Hi Derek, missed you in the café this morning, not sure if you are interested, but I’ve got another Heat Pump installation hopefully. Learned so much on the first installation, would you be interested in helping me, it’s a big house, to be honest not sure if I can handle it on my own.

Derek, how many days do you want from me and what do you want me to do?

Tom, well it’s going to be a complete strip out of all the heating as is, so it’s the full Monty nice project.

Derek, how big is it?

Tom, 7 bedrooms, 2 bathrooms, pretty big, Large combined lounge kitchen extension, shame it could have had some underfloor heating, small office, huge garage so plenty of room for the kit. They have an outdoor pool but I won’t be touching that, it’s on its own Heat Pump already had it for around 15 years, they run it on Economy 7, said Calorex on the badge never heard of them which is interesting, big thing covered in moss and running.

Derek, have you done all of those heat loss calcs stuff you go on about?

Tom, yes, it’s an older property, some solid external walls, some cavity but all in all great condition, also some older double glazing and some single glazing. Roof space is huge, so I’ve told them it needs a lot more insulation, I’ll get someone special to do that, can’t cope with all the dust and fibreglass.

Derek, why bother?

Tom, well it is a Heat Pump, so best to reduce the losses where we can. The customer is up for it, I think the pool HP made them think about going down this route.

Derek, OK, what’s the existing boiler size.

Tom, around 40kW’s perhaps a bit more, no modulation to old a model it’s on or it’s off, but if it’s coming out not really an issue is it.

Derek, What about the DHW?

Tom, well it’s an old cylinder I think a Y plan set-up, little if any insulation on the cylinder one of those wrap around jackets held in place by string.

Derek, can’t beat a “Y plan”

Tom, well it won’t be with the new kit, it’s all controlled via the HP controller, and weather compensation.

Derek, so what’s the existing system temp running at?

Tom, well I think around the 70’s, perhaps more, and the boiler is probably around 50-60% efficient but again not relevant with the new HP. The existing boiler flue goes up an old chimney, so I need to see about capping it off, may get some advice, don’t want a load of damp issues later.

Derek, I hope you know what you’re doing, don’t blame me if it all goes belly up, how many radiators?

Tom, well I counted 21 in total including the bathrooms I’ve got to pop back again so I’ll double check, but single panel so not very good, again that will all change. My big problem is I want to ensure all the new pipework not exposed will be insulated, some in the roof space, quite a bit under floor boards and a boxed in riser. Customer happy for this to be taken out and new boxing in when the job is up and running and leak tested.

Derek, sounds like a lot of work are you sure about it.

Tom, yes, absolutely.

Derek, so what do you think the new flow temperature will be?

Tom, I’m aiming for 45c flow to start with, but who knows that in time may drop a bit. Something the weather compensation can deal with so I’m told, Oh yes you can have an App on your phone, how clever is that.

Derek, what! That will never work you must be mad.

Tom, Derek, you have to start thinking a bit differently, I know you’re not a fan of HP’s yet, but they work at lower flow & return temperatures than what you and me have been doing for decades. Just because something is different doesn’t mean it’s wrong. All I want is your help and muscle not your brain, oops sorry, I’m at risk not you and in time you may feel differently, OK.

Derek, OK, so how big is the new HP?

Tom, so far, I’ve got it to around 11kW’s plus the DHW, I’m going to Heat Engineer and get it checked out great bloke Rob, I must say it surprised me.

Derek, blimey I need to start getting my head around this lot, let me get it straight you’re going to heat this house at around 45c flow, and the HP is 11kW’s yet it’s got this huge existing gas boiler in.

Tom, yes.

Derek, explain it to me I am totally confused, are you on another planet with these HP’s.

Tom, well I was a couple of months ago or more, but the course I went on convinced me and showed me how to size the new radiators to meet the room heat loss, I did this course run by Heat Engineer. Simply put you need a bigger surface area of radiator to get the correct output for the room, and ?given flow temperatures of 45c. Trouble is we well most of us haven’t had much education on this so it all feels alien, but when you get it, it’s not. This will blow your mind the TD’s around 5c.

Derek, TD what’s that?

Tom, well it’s part to do with water velocity in the pipe, pipe sizing and correctly selected Heat Pump circulator. It’s all in this course, my head hurt for a while, but I’m getting there. Well with the HP it only needs a 5° difference water in water out. Unlike what we used to do and some still do, like 70 plus flow and return around 60 or less. Oh by the way, Someone in the wholesaler this morning told me we have some new amended Rules Part L we have to look into, pretty serious stuff so they said.

Derek, you’ve lost me, never read them, wouldn't know where to find them even.

Tom, forget it for now I will explain later on. I may not use a buffer this time, not sure yet, need to speak to a Guy called Brendon on LinkedIn, seems to really know his stuff, good man I’m told.

Tom, anyway I’m going to run all of this past the Manufacturer in the 1st place, get their opinion and Brendon’s and get all the kit sorted. I’m also going to talk to a company called CPV about pre-insulated piping as the outdoor unit will be sited about 15m from the external wall I want to take the pipes through. I’ve seen loads of pictures on the NET and the pipework looks bloody awful, right mess, taped up insulation, bits missing. CPV have launched a new range called Hiline Clover, funny shape as you lay it vertically in the trench. Their Reps are very good and will hold your hand to install it all properly.

I also want to talk to Paul the electrician you know Paul, good man, the dis-boards in the garage and I will need mains supply adjacent to the HP, all waterproof with a local isolator IPP 66 I think, he’ll know, I’ll give him the HP electrical loads or send him the unit spec, one less worry for me. Hopefully the spare ways are big enough, I hope.

Anyway, when I get it, all sorted, I will ring you and you tell me when you are around to help, Cheers.

Derek, thanks Tom, I’m getting quite interested in all this, you never know, you may even convince me one day. It would be good to better understand all of this, are you going to the Installer Show?

Tom, yes, we could go together save some diesel, but don’t want a load of Bull-shit from any sales man or woman. It’s a great new start for me and it’s future proof, HP’s will be around for some time to come, as long as other installers follow my example and willing to learn, including you Derek!!

Derek, OK, keep your hair on!

Some really good videos on You Tube, some are a bit too techy for me, I’ll get there in the end, see you in the morning, are you going to the café

Derek, yes, it’s your turn, by the way don’t tell the wife about the sausage butties, she says I’m putting on weight, I say I’m working it off Ha!

?TO BE CONTINUED.