Climate Change

Climate Change

This post delves a little in my motivation for building a home instead of buying one. I've been asked this question a few times and I don't think I'm explaining myself well enough so I'll try coalesce my thoughts here to help me in the future when quizzed.

I read a book just recently I referenced in my last blog post. It captures perfectly the type of information that makes most sense to me. A 360 degree high level view of how serious the problem of changing our energy demand to renewable resources really is. The Author builds up two bar charts, one of the various types of energy demand we each personally create, the other how we can meet that demand with renewable resources. The scale of what is needed in the renewable sector is not anything we can solve personally, it will take national and global efforts to even approach a solution. I don't see this being possible with political will, we're going to need a United Nations with a big stick to beat the apocalypse in this race. And our Children are the prize.

Sounds nice doesn't it?!

The book is call "Sustainable Energy - Without the Hot Air!" - you can download a free PDF here:
http://www.withouthotair.com

So, turning off that mobile charger when it's not in use isn't going to piss on this inferno so what can we do?! Educate, pay attention. Avoid the media, tune into real scientists and websites that prove facts clearly so we can put pressure on our society to change. And I'm not even going to point you there, time to switch on and be active in this area, sorting out the fud from the facts and learn who to tune into and trust vs who is just mouthing bullshit.

For my opening question, our existing housing stock is so crappy, it's unreal. Regulation will never trump personal responsibility and societal norms (peer pressure). We're ending up even today with houses that are built the cheapest way possible while still meeting regulations. There are exceptional builders but these are rare. It's all about profit and keeping the cycle going.

Building your own house exposes you to so many options. It's a steep learning curve but only a new house is going to meet the air tightness, levels of insulation and standards that YOU set, above and beyond what Governments believe are necessary. And there is a significant gap. Now, you can't micro manage every contractor so you have to employ the best you can on faith and hopefully get 98% of what you intended but that's still a world of difference from existing mass developed housing stock and a house you personally have a stake in.

One of the solutions offered in the book is to reduce our demand for energy. We'll always have more devices to plug in, altough these are getting more efficient - so looking at hot water and heating consumption requires a rethink of how we design and layout our houses, even the size is important. We take on this responsibility when designing a house alongside Professionals and I've decided that the Passive House standard is where I want to go for this reason. The options of using Warmcell insulation, Fermacell drywall, non VOC building materials and furnishings, non formaldehyde flooring is going to drive up the cost a bit but each of these elements improves the quality of my life, reduces the embodied energy in manufacturing the building materials as many are made from recycled products and gives me a sense of doing the right thing in challenging myself to build more sustainably. Cradle to cradle is a term I suggest you might look into....

Whatever your motivation, using the renovation grant to improve the energy efficiency of your home is going to help, it's one of many steps we'll all need to take to move our Country towards the future where we eliminate the burning of fossil fuels to maintain our lifestyles. Let's hope we all hear the message and play our part so our children can play theirs without too much of a stacked deck against them.

Enjoy the Race!

Heating Philosophy

Heating Philosophy

I thought I'd use this post to delve into two options I'm considering for space & hot water heating in my new home. One uses a Hot Water Tank and the other instant Hot Water with no tank.

Each has it's own attributes but some of the factors I'll be using to decide on which route to go are:

• limited space heating required, mostly wintertime
• Myself: limited hot water usage, 3 minute shower daily, some washing up at sink, shave once per week
• Other person: Unknown
• Occupancy max of 1 to 2 people

So, the reason this is more of a philosophical argument is that for years everyone automatically got a hot water tank. But my issue with that is for one person it's overkill. Even a small one. The standing looses and constant need to top it up means storing hot water at 55 degrees becomes a drain on a good air source heat pump. Why not just create it as you need it? It comes down to a simple principal:

Store & Loose OR Create & Use!

So, why not store it and go conventional - here are my list of pros / cons of a hot water tank system:

Pros:

• Plenty of knowledge around on how to do this, there are some interesting variations but it's every conventional, any plumbers can put one together for you
• Good store of ready to use hot water at all times of the day (hopefully!)
• Better for larger households
• Can use pressurised system to pump hot water around a circuit continually to ensure no dead legs
• Can supplement with Solar Thermal system

Cons:

• Recharge time, teenager 30 minute shower vs timing of your own can be frustrating! 
• Standing losses, both in the tank itself and in the hot water pipes, the water essentially goes cold in the pipes after an hour despite any insulation
• Heat from tank will leak into surrounding spaces, not nice in an air tight house in summer!
• Dead Legs between hot water tank and use points, wastes a lot of water each year....vs water charges!
• Space required for Hot Water Tank, position vs use points hard to optimize in most houses
• Legionella risk mitigated by storing at 55 degrees +, or must use immersion once a week, ASHP isn't optimised to heat hot water to this temperature, lowers COP. 

And as for creating it as you need on demand:

Pros:

• You create exactly the quantity you need, at the exact temperature you need, precisely where you need it (or close enough!)
• No risk of Legionella as no hot water is stored
• Stops waste of using kettle to boil imprecise amounts of water that's not even needed / used
• No Dead Legs if using electric, very short runs between showers possible if sited above / below each other
• Can supplement power requirements by using Solar PV & Sunamp PV to store daytime energy

Cons:

• OK for 1 or 2 people but do efficiencies drop after that for larger families? Or do you just scale it?
• If using Combi gas boiler - still has dead legs
• Electricity use for all hot water needs if no Combi
• Increases reliance on Electricity as sole energy point if not using Gas Combi, more sensitive to price fluctuations
• Little knowledge out there, relying on manufacturers / suppliers for diagrams, troubleshooting etc, riskier as few have done it in practice. 

My current goal is to use an instant water heater in the Kitchen under the sink. Then for the showers, I hope to connect Solar PV panels to a Sunamp PV (for preheat) and Stiebel Electric water heater:

http://www.ithouk.co.uk

http://sunamp.co.uk

https://www.stiebel-eltron.co.uk/en/products-solutions/dhw/instantaneous_waterheater/overview.html

I've found good info on some of these options on the excellent buildhub site:

http://forum.buildhub.org.uk

There are still some interesting options such as Eco Heating systems with a Twist:

https://originaltwist.com/2016/06/23/eco-heating-system-for-heat-pumps/

Tank in Tank systems also provide some skews to the traditional approaches:

http://www.greentherm.ie/solutions/thermal-stores-and-hot-water-cylinders-from-greentherm/

Greentherm do a great Solar Thermal drainback system which is safer than one which leaves fluid in the panel which when not being pumped turns to sludge. But these are options for another day!!

Now, the focus here was mainly on hot water where most of the house energy is concentrated but space heating is also required. An air source heat pump is a good option when paired with under floor heating but ideally you want to gain some synergy between the hot water and space heating. There's no reason why you can't add an ASHP into the Sunamp/Stiebel combination, it just adds to the cost though. Also some MHVR units combines an ASHP anyway. Lots to consider so it's not a choice to be made in isolation if cost and all those maintenance charges are a worry. 

I hope the information above gives you some insight into the possibilities available today that weren't choices even 10-15 years ago. I'm sure there will be more options in another 10-15 years! Best of luck investigating your own space/hot water heating solutions. Find a good oracle/tradesperson you trust and see what they suggest while leaving options open for tweaks in the future......

BTW - I'm reading an excellent paper called "Sustainable Energy - Without the Hot Air!" - you can download a free PDF here:
http://www.withouthotair.com
Chapter 21 really delves into the best way to heat your home and get hot water...!

Project Update August 2016

Project Update August 2016

So, moving onwards slowly!! I've been working with the Architects to shift the ridge-line left to right rather than front to back. This gives me a short roof to mount solar panels on. I've also been looking into Vortex wind turbines suitable for domestic use but my boundary is far too close to be allowed. It can work with turbulent air and we had a LOT of that this weekend so hopefully this or similar technology will emerge one day we can use in suburbia!

I got two drawings from the Architects last week, and decided to do a third myself taking things a little further. I blanked out the insides of one of the sketches and printed out a few copies. This gave me a blank canvas to doodle on using a pencil and rubber, haven't used these in years. I could have used Google Sketch-Up or something but I was travelling and it meant any changes only took a minute or less or if I wanted to review something, just a few seconds.

The stairs as always is challenging in a small house, headroom, where is pokes into the upstairs etc really determines the room spaces you'll end up with. I'm looking at the kitchen / living space at the back of the house but this space faces north. I'd like big windows but this poses a heating challenge and may not be possible. I wonder if the quality of light will be sufficient either? The current house I live in has a kitchen that is rear facing but two windows allow you to see out north and east which is not too bad.

I've opted for a small 2 meter by 1 meter washing / drying room off the kitchen but the upstairs bedroom is over this. In order to access two sides of the clothes horse I'm going to ask for no walls but rather a set of bi-fold french doors that open this space all the way. In other words the doors open the entire space and join it to the kitchen. Of course the upstairs bedroom needs to rest on something so I'd imagine some steel beam will be required. Then with a good extract duct this space can quickly dry clothes!

The rest of the spaces are fairly conventional. I measured all the rooms and the couch in my current house to give me an idea of the minimum space I'd require of each room in my new house. The laser pointer is really handy in this regard! A few doodles later and I was able to mark my own bedroom up in my head and see what space I would require either side of the double bed and to allow me to open the wardrobe doors comfortably. The living space was trickier but I felt a 4m x 4m space was ideal to allow me to walk either side around the couch, have space behind it and keep 2 meters away from the TV. That's 16 meters squared wasted though which is a lot!

Just waiting for the Architects to respond now and see if they think this layout if a runner or not!

Update: Well, there was a concern that the living space at the back of the house would be too dark but adding roof windows should help. As we've extended the depth of the building a bit I'm wondering if the vaulted ceiling / warm roof will stretch that far or if Glulam beams will be needed. There was also something new I'd learnt about fire regulations. I was hoping to look down on the open plan area from the top of the staircase and leave the hallway open but if you do this the Kitchen must be enclosed which defeats the purpose in my opinion. The risk of fire starting in the Kitchen is a strong reason to close off the front of my house to the rear, so we've added fire rated glass doors and shut off the top of the stairs to separate the open plan space to the rest of the bedrooms vs hallway / stairs which form the fire escape routes. So, now the Architects are off to render a few 3D sketches I can use to talk to the neighbours, pre-planning and the site owner etc. September should be an interesting milestone if I can exit Stage 1!!