putting boiler and tank in shed - any disadvantages?

NextSteps

This forum is a great resource - thank you!

The builder suggested putting the (gas) boiler and (gas/solar) hot water tank in the shed at the bottom of the garden when we do up the house, and putting the solar panel on the roof of the shed, where it'll get light all day. My initial reaction is

1. Won't the water get cold coming to the house, no matter how well lagged the pipes?
2. What if I accidentally put a spade through the pipe?
3. Won't it take a lot of pumping to get the water all the way to my upstairs shower - and therefore lots of electricity?
4. And, finally, will I have to wait 5 minutes for the water to run hot in the shower?

Can anyone shed any light?

UB

JamesM

UB wrote:

This forum is a great resource - thank you!

The builder suggested putting the (gas) boiler and (gas/solar) hot water tank in the shed at the bottom of the garden when we do up the house, and putting the solar panel on the roof of the shed, where it'll get light all day. My initial reaction is

1. Won't the water get cold coming to the house, no matter how well lagged the pipes?
2. What if I accidentally put a spade through the pipe?
3. Won't it take a lot of pumping to get the water all the way to my upstairs shower - and therefore lots of electricity?
4. And, finally, will I have to wait 5 minutes for the water to run hot in the shower?

Can anyone shed any light?

UB

I am no expert, but what you are saying makes sense. It seems crazy having the source so far away from the end user.
Jim.

Mac28

Am hoping to start building a new house pretty soon. got some rough quote recently about solar panel for just heating water alone. Was quoted about €5700 for solar panel to heat water alone. the panels would be attached to a garage that is seperate from the house. the pipes going into the house will have some sort of insulation around them that gives them minimal heat loss 'cos this was the first question I asked. The only problem that I seen was that this might only heat the water to a certain temp and that the rest of the heating may have to be done by electric/gas. the price was only rough and the site would have to be visited but was for a 6x square meter panels. They recommemded 1 square meter panel for each potential person in the house. productivity of these panels may be lower in the winter

davidoco

If you use these pipes https://www.rvr.ie/default.aspx?subj=catalog/ProductsList&catIdPath=0_70_92 you will have minimal heat loss. They are used in Europe for district heating systems. Depending on the distance you should consider using this http://www.grundfos.com/web/grfosweb.nsf/Webopslag/comfort-features which circulates the hot water.

JamesM

davidoco wrote:

If you use these pipes https://www.rvr.ie/default.aspx?subj=catalog/ProductsList&catIdPath=0_70_92 you will have minimal heat loss. They are used in Europe for district heating systems. Depending on the distance you should consider using this http://www.grundfos.com/web/grfosweb.nsf/Webopslag/comfort-features which circulates the hot water.

UB says the boiler and hot water tank are at the bottom of the garden. If this boiler (Combi ?) or hot water tank feed the shower, he is going to have to run off a lot of water before the water in the shower gets hot. And there is going to be a lot of hot water just sitting under the garden when the shower is turned off. But maybe this boiler and tank just feed a hot water cylinder in the hotpress ?. Then if the pipes are well insulated, it might not matter too much.
Jim.

NextSteps

JamesM wrote:

But maybe this boiler and tank just feed a hot water cylinder in the hotpress ?.
Jim.

Jim, no, the builder's idea was to put the hot tank/cylinder and the boiler in the shed at the bottom of the garden. So you're right, the waste of water is another issue - 20m or so up the garden and then up to the bathroom. I don't know how many litres that is, but it seems like a lot.

davidoco

JamesM wrote:

he is going to have to run off a lot of water before the water in the shower gets hot. And there is going to be a lot of hot water just sitting under the garden when the shower is turned off.

The Grundfos Comfort means that there will be hot water instantly at the shower, no run off required, see the movie on the link above. It may not be efficient when it comes to electricity or any heat loss but it would still work a treat.

NextSteps

Thanks for those links David. The www.rvr.ie one in particular has a very clear explanation of everything about solar panels, which is very useful. I figured out the kit I think I need (https://www.rvr.ie/default.aspx?subj=catalog/ProductDescription&catIdPath=0_70_74_78_85&productId=ASK011). As for the pump, it seems like a great idea if it can be set to particular high-use times (morning and evening), which it seems it can.

Now I just need to get a registered installer!

davidoco

If it were I UB I would put the boiler and panels in the garden ok. Since you are going for the steel cylinder I would fit it somewhere in the house, anywhere as space can’t be that tight, under the stairs, in a larder press in the kitchen, in one of the wardrobes, in the attic ANYWHERE. You would then have your plumber pressurise it so that you have no requirement for pumps etc and have perfect pressure and showers all over the house.

Your panels and boiler feeding the cylinder would be at the bottom of the garden and you would need to invest in those insulated pipes to bring the boiler flow and return and the solar flow and return into the house.

Also another suggestion 1sq m of flat panels is not the same as 1sq m of evacuated tubes. I can't recommend any particular make of either but if I were installing I would go for the evacuated tubes. Read the q&a here about panels and tubes http://www.sei.ie/index.asp?locID=1010&docID=-1#tubes

NextSteps

davidoco wrote:

Also another suggestion 1sq m of flat panels is not the same as 1sq m of evacuated tubes. I can't recommend any particular make of either but if I were installing I would go for the evacuated tubes. Read the q&a here about panels and tubes http://www.sei.ie/index.asp?locID=1010&docID=-1#tubes

To be honest I reckoned that, being long on space and short on money, it would make more sense to have a few extra sq m of flat panels. From what I understand the evacuated tubes are more efficient, so you need less sq m, but more expensive per sq m.

It seems the grant is per sq m no matter what type of panel, so therefore you would get more of a grant and spend less, for the same benefits, if you had say 5sq m of flat panels instead of 3.5sq m of evacuated.

But I'm open to correction!

davidoco

Panel v Tube. From looking at the RVR site you would be paying for the kits(VAT excluded) 4295 for 5m2 of flat and 4550 for 4.3m2 of tube. That's 1m2 of panel costs €859 and 1m2 of tubes costs €1083 so 25% more for tubes.

When you take the grant into account you are only paying €535 more for the tubes (excl VAT). Grants 2000 v 1720.

See for debate http://www.rayotec.com/htm/solar_schott/schott_techno.htm and the RVR Q&A section

So pay €535 more (my rough figures only 12%) for the benefits of tubes as outlined in the last paragraph by Schott and RVR.

JamesM

davidoco wrote:

If it were I UB I would put the boiler and panels in the garden ok. Since you are going for the steel cylinder I would fit it somewhere in the house, anywhere as space can’t be that tight, under the stairs, in a larder press in the kitchen, in one of the wardrobes, in the attic ANYWHERE. You would then have your plumber pressurise it so that you have no requirement for pumps etc and have perfect pressure and showers all over the house.

Yes, You certainly need to put the cylinder in the house.
Even with it in the house, the Grundfos Comfort seems to waste a lot of heat. Constantly heating those pipes would be as bad as heating an extra radiator. It might balance out if you were paying for your water.
Jim.

Reyman

Surprisingly if you used a 1 inch pipe from the shed you would only have about 3 litres of water in each leg of the pipe. So not a huge efficiency loss in wasting 6 litres of water if you're only running the hot water occasionally.

But if you're running it a lot forget it you'll waste a fortune.

Anyway apart from that it sounds to me like a bad idea you would be waiting forever for the hot water to come out of the tap. This is the kind of mistake that would drive you mad over the years !

jones085

There is no problem with the heat sources so far away, but there are a few buts as it where. You will need to pipe the water from both the cyclinder and the hw cylinder in whats generickly known as district heating pipe. It speically designed for this purpose and in my opinion the only way to do it. It costs anywhere between 35 and 50 euros a meter!!! It normally comes with two pipes inside. So you would need two (inch or more) pipe in one and an inch and a 3/4 or 1/2 inch in the other. for the hot water circuit.

The hot water would need to have water is called a secondary circuit on it. This effectivly turns the hot water into a circuit, and is pumped round the house in usage times. So the draw off is always short in these periods.

So you have the cost of the piping and extra install and supply cost of a secondary hot water circuit. including bronze pump.

You are not actually supposed to have a run of hot water much over 20m in total anyway.

Regards

Simon

NextSteps

Thanks for all your replies, things are a bit clearer in my head now.

What I think I'll do is to put the panels and boiler in the shed, connect them with the tank somewhere in the house with a district heating pipe, and pressurise the tank so that I don't need a pump. And the solar panels will probably be the evacuated type, considering the benefits. That way the boiler will be out of the way, and I won't be waiting ages or wasting water and power running hot water for the shower.

Thanks!