Bed and Breakfast Solar Upgrade?

mickrick1

Hi,

I'm fairly new to the Renewable Energies thread. I have been reading through all threads relating to solar panels and note that there are quite a number of posters who have either experience of installation of solar panels or have them installed in their homes. For this reason I hope that I might be able to get some direction here.

I own a bed and breakfast near Galway and use my oil burner to provide hot water from mid April to mid September approximately. Last year this would have cost me between 400 and 500 Euro. I have recently upgraded my boiler to a condensing boiler which hopefully will show energy savings in the future.

Due to the number of guests we cater for (approx 16-20) for most of July/August, (approx 12-16) June/September and so on, plus my family of 2 adults and 2 children I am seriously considering upgrading my hot water tank from 300 l to 500 l. This will involve a significant enough expenditure to supply the tank and have all the relevant plumbing done. With this in mind I was thinking why not go the full hog and install solar panels also. At least then I can avail of the SEI grant.

I am aware that some will argue that the savings solar panels provide versus a condensing boiler might not be that significant and payback could be over a considerable period. I do feel however that my circumstances as outlined above may sway the argument.

The rear roof of my house is facing south/south west. I have a natural slate roof and would have a preference for flat panel because of the aesthetics. I am open to direction here however. If I want to go in roof as opposed to on roof this shouldn't be too much hassle as my brother roofed the house.

I hope that I have given all the relevant information. Any help or direction would be very much appreciated.

Thank you

Mick.

quentingargan

Hi Mick,

For a larger volume of water, such as a B & B, I would prefer to use multiple cylinders, each being a pre-heat for the next one. See enclosed sketch.

The advantage is that on the fringes of the season, when you have lower occupancy, you may have enough from your panels to heat one cylinder with 300L of hot water. That's more useful than having 500L of lukewarm water. There are specialist solar controllers that can manage two, three of four such cylinders in series.

The main advantage of tubes over flatplate is that they work better in the fringes of the season and on more inclement days. That may not be such an issue for you if your main demand is summertime. Personally, I would always prefer to use in-roof - much better protection from gales, and better structural integrity. It will cost a bit more initially, but is also aesthetically much more pleasing.

You should be able to get 30% of the total cost of the project from SEAI. With the increasing trend towards eco-tourism (especially in the B&B sector) there will be an appreciation of the pleasure of having hot water that comes from the light instead of the dark:)

mickrick1

Hi Quentin,

Thank you for your prompt response. I wasn't aware that you could fit multiple cylinders in series. I have a problem here though in that I have limited space. In fact it's going to be a struggle to fit a 500 l tank into our hot press. Could the extra cylinders be fitted near the boiler in our garage?

Cheers
Mick

quentingargan

mickrick1 wrote: »

Could the extra cylinders be fitted near the boiler in our garage?

Cheers
Mick

Hi Mick,

The cylinders all need to be in the same place for this to work, otherwise there are substantial heat losses in the pipe. Ideally, the panels need to be close to the cylinder as well. On top of that, I prefer short pipe runs from the cylinder to the taps to prevent any need for a "secondary return", or "instant hot water system" in a B&B.

You can do a setup where the first cylinder is near the panel, and it in turn pumps water occasionally to the other cylinders for storage, but usually in such a configuration, the other cylinders are where the water for the taps comes from. If the garage is a long distance from the kitchen / bedrooms, this may not work so well. Q

dathi

perhaps he could put a small tank eg 200 ltrs in the atic above the hot press instead of the garrage

quentingargan

dathi wrote: »

perhaps he could put a small tank eg 200 ltrs in the atic above the hot press instead of the garrage

Yes, that's a good idea. The existing 300L cylinder, if it is a good one, would be put up there, while the new twin-coil one would replace the existing one.

mickrick1

Good thinking guys but being a B&B my attic is converted. That's where the family live during the summer. Is it possible to have a cylinder on the horizontal? If it is I could maybe squeeze it in.

homer911

I'd be concerned as much about the weight as the space, unless you are in a bungalow..

quentingargan

mickrick1 wrote: »

Good thinking guys but being a B&B my attic is converted. That's where the family live during the summer. Is it possible to have a cylinder on the horizontal? If it is I could maybe squeeze it in.

Normally cylinders are tall and relatively thin to maximise stratification (the ability of the water at the top to stay hot while the water at the bottom is cold). Stratification may be less of an issue with the pre-heat cylinder, but I would have seen the main advantage being able to use your existing 300L one, and that won't really work.

Your best bet is to get someone to have a look over and see what might fit where, and what might work. It is possible to run two cylinder some distance apart with heat exchange between the two cylinders, rather than using them in series as in the attached schematic which comes from one of the more advanced solar controller manuals. Q

ccsolar

Hi Mickrick1
If you apply for a grant through the SEAI, you might want to consider the Renewable Heat Deployment Programme as this will allow your business to avail of a 30% grant + the extra costs can be written off against TAX.
See attached link.
http://www.seai.ie/Grants/Renewable_Heat_Deployment_Programme/

If you apply for the grant through the greener home scheme you will only be able to claim a maximum of €1800 for the solar system.

CC

mickrick1

Back to your earlier point Quentin about multiple cylinders. I might be able to squeeze another cylinder into my hot press but my missus will probably go spare because that is where all bed linen is stored. Would I get away with a 200 l solar cylinder in series with my existing 300 l cylinder? This could have an impact on material spend.

mickrick1

ccsolar wrote: »

Hi Mickrick1
If you apply for a grant through the SEAI, you might want to consider the Renewable Heat Deployment Programme as this will allow your business to avail of a 30% grant + the extra costs can be written off against TAX.
See attached link.
http://www.seai.ie/Grants/Renewable_Heat_Deployment_Programme/

If you apply for the grant through the greener home scheme you will only be able to claim a maximum of €1800 for the solar system.

CC

Thanks for that CCSolar. I will bear it in mind.

mickrick1

homer911 wrote: »

I'd be concerned as much about the weight as the space, unless you are in a bungalow..

Cheers Homer. If I can fit the extra cylinder in the hot press, weight is not too much of a problem as we have hollow core between the ground floor and first floor.

the watchman

quentingargan wrote: »

Hi Mick,

For a larger volume of water, such as a B & B, I would prefer to use multiple cylinders, each being a pre-heat for the next one. See enclosed sketch.

The advantage is that on the fringes of the season, when you have lower occupancy, you may have enough from your panels to heat one cylinder with 300L of hot water. That's more useful than having 500L of lukewarm water. There are specialist solar controllers that can manage two, three of four such cylinders in series.

The main advantage of tubes over flatplate is that they work better in the fringes of the season and on more inclement days. That may not be such an issue for you if your main demand is summertime. Personally, I would always prefer to use in-roof - much better protection from gales, and better structural integrity. It will cost a bit more initially, but is also aesthetically much more pleasing.

You should be able to get 30% of the total cost of the project from SEAI. With the increasing trend towards eco-tourism (especially in the B&B sector) there will be an appreciation of the pleasure of having hot water that comes from the light instead of the dark:)

Hi Quentingargan,
I read your posting with interest and have stared at the schematic diagram of the multiple cylinder system you refer to and I still can't quite figure out how that works. If you have a moment and have one to hand could you direct me to another resource location where I can learn more.

Thanks for your time.

quentingargan

the watchman wrote: »

Hi Quentingargan,
I read your posting with interest and have stared at the schematic diagram of the multiple cylinder system you refer to and I still can't quite figure out how that works. If you have a moment and have one to hand could you direct me to another resource location where I can learn more.

Thanks for your time.

Hi Watchman,

The attached picture which comes from the manual for the controller might not be any clearer, but the water you use comes into the cold feed on the cylinder on the RIGHT, the hot outlet from that is fed into the cold feed on the next cylinder in line. The hot outlet from that is the connected to the cold feed from the next one etc., so there are three pre-heat cylinders and one final cylinder.

The solar panel heats the cylinder on the LEFT first. When it is up to temperature, the solar then heats the next cylinder and so on.

Its not commonly used, but it is a lot more effective than having one single 1,200L cylinder, and also usually a bit cheaper as well.

the watchman

Thank you, now I understand. Fascinating.
Thanks again for your time.

mickrick1

Seriously considering the solar upgrade now. Would look to install in early spring next year just before the start of the B&B season. Will most likely go for 500 litre cylinder (I need this anyway because existing 300 litre cylinder is too small for demand) with on roof flat panel solution.

I am considering purchasing the materials myself and getting my plumber who has completed more than 30 solar installations to install. Could anybody PM me with contact details for good quality and preferably competitively priced products.

Thankyou Mick.

the watchman

This looks interesting.Came through my letterbox recently. Seems to incorporate two types of solar technology in one unit and a few other interesting features..., maybe useful ..

Wally Runs

mickrick1 wrote: »

.... I might be able to squeeze another cylinder into my hot press but my missus will probably go spare because that is where all bed linen is stored.

I am just a home owner, but having renovated and come from the old copper HW tank in the hot press to solar and an insulated tank etc. We were advised that aside from the extra space a larger tank would take in the hot press it would also give off much less heat. When you think it, what about is the point of having such a well insulated tank.

Our solution was to move the tank to the basement and place a small rad in the hot press (or elsewhere in your case). This gives us a hot press in the winter, when your laundry needs that extra bit of airing and the heat is on and in summer the clothes are pretty dry off the line.

Now, I understand that you could run a small rad off the solar tank and/or heating as a heat dump (should the sun really be out in the summer). This would mean that you could use all your present hot press space for a series of tanks and elect another area of the house as an airing room. If you had night rate ESB could put in small electric oil rad on a timer to give you heat for a hot press in the summer?

I am sure those with more experience could comment.

quentingargan

Wally Runs wrote: »

I understand that you could run a small rad off the solar tank and/or heating as a heat dump (should the sun really be out in the summer). This would mean that you could use all your present hot press space for a series of tanks and elect another area of the house as an airing room. If you had night rate ESB could put in small electric oil rad on a timer to give you heat for a hot press in the summer?

I am sure those with more experience could comment.

The radiator for a heat dump is usually quite large - needs to dissipate quite a bit of heat, and I prefer to put it somewhere it can't be muffled with towels. If you cover it with clothes, it can get extremely hot (up to 140 degrees!).

Nice thought, but better to use that rad in the bathroom if it suffers a bit of condensation in the summer with the heating off. It won't come on all that often anyhow.

Wally Runs

Many thanks, in the end we went with a small rad connected to the heating and it works a treat. The system we ended up with does not require a dump.

The airing cupboard is in the bathroom so any excess heat is given off to the room. In the summer the outdoors is fine. Not sure how it would work for a B&B where you have greater need for laundry turn-over. I think that the whole 'green' B&B would appeal to tourists in the main so best of luck.

The return on investment may not be all in terms of energy saved but extra nights booked. I can imagine seeing the panels and going 'oooh nice long hot showers, just what I need mmmmm!' Could play hell with the water supply though.