Solar hot water, hydronic heating

I’ve been interested for a while in getting underfloor heating, probably of the hydronic variety.  Underfloor heating offers some benefits in terms of less air movement and noise, and of giving a more liveable ambient heat – there is some evidence that the warmth of your feet is a key determinant of how comfortable your house is in winter.

The concept has been to use a large water storage tank as thermal mass, and to use evacuated tube water heating to heat that tank.  This gives most of the benefit of having large thermal mass in your house, whilst giving control over when you take the heat out of that thermal mass.

This blog post explains why I think that’s probably not a great idea anymore, and what I’m thinking instead.

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9: Adding the teams entity, and links from clubs to team

In this portion of the tutorial we’re going to extend to the teams entity, and build the links between clubs and teams.  This means passing parameters to our list controller, and dealing with optionality.  We’ll let people create a team from within the context of a club – in which case we auto-populate the club, and we’ll let them create a team standalone and pick the club from a drop-down.

This tutorial mainly consolidates what we’ve already done, but it lays the groundwork for some more interesting functionality later, including user authentication and an editable grid.

If you’ve dropped into the middle of the tutorial, you can find the code for the previous section at github: PaulL : tutorial_8.  You can go to the index page for this tutorial, or you can hit the tutorial menu above and see all the posts in the Rails 4 tutorial.

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Editable ngGrid, with both dropdowns and selects

I’ve been working on making an editable ngGrid, allowing users to directly edit the grid rather than going to a detail page.  I’m seeing that there are two modes of operation – for simple things (maybe changing the status of a bunch of items), it’s easier to interact with the grid directly.  When you want to edit a full item, you’d do this in the detail page.

The aim is to have a grid that you can edit directly, and have it save to the server when you leave the cell you’re editing (this is a reason you wouldn’t want to edit the whole record this way – you’ll end up with lots of spurious saves if the user has lots of cells to edit).

An option if you’re starting a new project now would be to look at my tutorial on the beta ng-grid 3.0.  This isn’t ready for production use yet, but feels reasonably close, so if you’re 3 months away from production it could be an option.  It has a nicer api for editing.

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Protractor and Dropdowns: validation

We use protractor for our end-to-end tests.  A variety of pages are suggesting that selection of dropdowns, and validation of dropdowns, is tricky.  And I think they’re right.

This post deals with a couple of code snippets that I’m using to deal with dropdown selection.

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