House Cooling ideas

[vivienz]

We keep having rain forecast, but it never arrives.  Hopefully the weekend rain will arrive and drown plenty of biting insects, they've literally been making a meal of me this last week.

 

Lizzie - Waitrose have lovely long chiller cabinet aisles and freezers, you could take up lurking in those although I suspect plenty of others are doing the same at the moment!

[newhome]

4 minutes ago, vivienz said:

 

We keep having rain forecast, but it never arrives.  Hopefully the weekend rain will arrive and drown plenty of biting insects, they've literally been making a meal of me this last week.

 

 

Same here. No rain even when it threatens. Really need a huge downpour now. Never thought I’d say that. Loads of annoying flies around too. I leave the back door open for a bit and there are damn flies everywhere. 

 

 

[jack]

This dry weather seems to have suppressed the usual plagues of mosquitos that come in through open windows overnight.

 

One thing to add to my earlier post: we have polished concrete floors throughout our ground floor, which helps with heat transfer. Tiles presumably would be similar, but i imagine you'd want to think about what affect other types of flooring would have. This wouldn't work very well with carpet, I imagine.

[vivienz]

I can't think about flooring at all - too busy concentrating on not scratching the mozzy bites running up my shin:(

[lizzie]

13 minutes ago, vivienz said:

Lizzie - Waitrose have lovely long chiller cabinet aisles and freezers, you could take up lurking in those although I suspect plenty of others are doing the same at the moment!

Marks and Spencer Simply Food store is my go to place......almost have my own chair I spend so much time in there LOL

[lizzie]

@jack I have porcelain tiles throughout

[Ferdinand]

I had te house closed up all day to day to go on a Fish Cooking course. All that filleting has gone some way to convincing me that rustic presentation of whole fish is best.

 

Back on point ... But on return, the outside temp as read by the car has been 33C, but the inside core temp at home as read by the Hall stat is 24C. Big difference. The house is I think to approx 2010 regs.

 

Tonight there is very little I can do to purge the heat, since outside is warmer than the inside. So it would need active cooling. Hoping for a period before breakfast where the air is cooler for a bit.

 

Ferdinand

 

[newhome]

My house was the same. I was out at work for 12 hours and returned at 7pm to find every room at 24 degrees. That hasn’t changed overnight and the temperature is still 24 degrees. 

[Ferdinand]

12 minutes ago, newhome said:

My house was the same. I was out at work for 12 hours and returned at 7pm to find every room at 24 degrees. That hasn’t changed overnight and the temperature is still 24 degrees. 

 

My outside temp has now fallen a bit since 4am. Everything is open for half an hour !

[newhome]

Bored of the heat now TBH. This is Scotland. No one lives in Scotland to be complaining that it’s too hot! 

[SteamyTea]

My house was shut up most of the day, but you can see when the wind picked up in the afternoon and when I got home.

[lizzie]

@SteamyTea  what are you using to monitor your temps, that looks a really good easy to see and understand chart.

[SteamyTea]

I use a Raspberry Pi Zero W with some DS18B20 1-wire sensors and some DHT22 sensors.  Also stuck on a real time clock.

Very cheap kit, around 20 quid.

The chart is just knocked up in Excel, though there is software for the RPi that can do charts on the fly and publish them.

 

The advantage of the 1-Wire stuff is that you can daisy chain many sensors to 1 input pin on the RPI.  The DHT22 needs 1 pin per sensors, but there are about 20 spare pins, so that is not really a problem.

The software is easy to write, or copy, just depends how sophisticated you want it really.

 

Also pretty easy to get it to turn things on and off i.e. a fan, airco unit, heater.

 

Edited July 27, 2018 by SteamyTea

[Jeremy Harris]

18 hours ago, jack said:

 

Just re-reading this and it isn't clear from my last couple of posts that I put in the code to make cooling mode accessible on our ASHP last week. I may have mentioned it on another thread.

 

Having now had another few days with the UFC on during this hot weather, I'm absolutely certain it's having a significant effect on the temperature upstairs, despite all the cooling being downstairs.

I reckon downstairs has been sitting at a very comfortable 20-21 deg C for the last few days (ASHP outputting a temperature of 16 deg C during the day - I'm just manually turning it on for most of the day while the sun is up so the PV is powering it). The temperature upstairs at the end of the day has fallen from, I guess, 26-27 deg C a few days ago to maybe 22-23 deg C last night, despite how hot it's been. Doesn't sound like much, but trying to sleep in 22 deg C compared to 26 deg C is a very different experience.

 

In any event, I'm sold on underfloor cooling as a solution for at least knocking the edges off extreme overheating once all the passive design features have been optimised. I think that if we just get external blinds installed on our bedroom windows and install the remote blind we have sitting in the garage for our rooflight, we'll have the problem completely licked for next year.

 

 

 

I was amazed at how effective under floor cooling was when I first tried it about three years ago.  It had a far greater impact on the house temperature than I expected .  I have ours set up automatically, with two thermostats in the hall.  One works as a cooling thermostat, and is currently set to turn the underfloor cooling on when the house reaches 22 deg C, and is on the heating system programmer, so set to come on at around 06:00 and off at around 18:00 at the moment.  The other is the heating thermostat, run from the same programmer, but set to come on at 20 deg C and turn the underfloor heating on.  The ASHP is programmed to deliver a steady 10 deg C in cooling mode and 40 deg C in heating mode, which seems to work very well.  In practice the floor surface never gets cooler than about 18 deg C, and the only condensation we get is on the floor heating/cooling manifold, when the system is in cooling more.  There's very little of that, so I've just placed a plastic drip tray underneath the manifold and natural evaporation seems to just remove the small quantity of condensate.

[PeterW]

@JSHarris do you have the wiring diagram that shows your heat/cool switch over on the ASHP itself ..?

[jack]

10 hours ago, vivienz said:

I can't think about flooring at all - too busy concentrating on not scratching the mozzy bites running up my shin:(

 

No mozzies here at the moment, but we have harvest mites in our garden and it seems I'm very tasty to them (wife never gets bitten). The bites are the itchiest things I've ever experienced in my life. I thought I'd conquered them by always wearing long trousers, but they got to me again a couple of days ago, one right on the outside tip of my ankle. It's driving me nuts!

[SteamyTea]

17 minutes ago, jack said:

It's driving me nuts!

Wish my girlfriend was an ankle biting mite 

[Jeremy Harris]

2 hours ago, PeterW said:

@JSHarris do you have the wiring diagram that shows your heat/cool switch over on the ASHP itself ..?

 

 

Yes, sure, it's done via two wireless thermostats, one set to cooling switchover mode, the other set to heating switchover mode (they are the same wireless stats, but have a link so they can be set to activate for cooling or activate for heating.

 

I used these to control some diode logic and relays that select the various options on the dry contact controlled ASHP.  The same unit also controls the UFH valve and the buffer tank valve.  First off, this is my ASHP dry/12V contact wiring panel, showing the various options that can be turned on or off by a dry contact between the common and the relevant terminal:

 

 

I used some DIN rail mount 12V relays and a small 12V DIN power supply, fitted inside a small consumer-unit type box to house the control relays, power supply and some DIN rail terminal blocks, to  make a DIY wiring centre for the system, the two room thermostat receivers are fitted on the wall above, as is the programmer.  The buffer tank stat has it's sensor bulb pushed into a hole in the side of the tank insulation and seems to work OK like that.  This is the box with the DIY wiring centre in it:

 

 

 

And this is the wiring diagram for the diode logic and relays.  There are three thermostats, one for hot water pre-heat call from the buffer tank, one for cooling call from the cooling stat and one for heating call from the heating stat.  When cooling id called for (and cooling is subservient to a buffer tank heating call) the buffer tank is isolated by a 12V motorised ball valve.  The system can heat the buffer without the UFH being on, as the UFH valve is one of those neat ,motorised differential temperature valves that @Nickfromwales found, that not only turns on the UFH but also runs it as a set 5 to 6 deg C differential between flow and return when it's powered on, which works far better than any thermostatic mixer valve and makes a mixer valve redundant. The great thing is that this UFH valve doesn't care whether it's heating or cooling, it still maintains the 5 to 6 degree different between flow and return on the UFH pipes themselves in cooling mode, which is ideal, as it reduced further any floor condensation risk.

 

 

 

 

 

[lizzie]

@SteamyTea thank you but way beyond me Im afraid!

[joe90]

Great wiring diagrams Jeremy, thanks (having a real hard time understanding this stuff, I prefer to dig with my JCB ?),

[mike2016]

14 minutes ago, lizzie said:

@SteamyTea thank you but way beyond me Im afraid!

FYI - There's a few simpler options to measure temperature / humidity. Saw a nice one called "sensorpush". Bit pricey on Amazon currently at £89, had been £50 so try ebay and they are more reasonable there. These connect to your phone with nice graphs etc!

Otherwise a standalone unit with a display - search for TP55 or TP65 on Amazon, very reasonable....@ £20 but don't seem to have any way to connect to a computer....

 

[mike2016]

I was talking about this topic with my Architect last week - we're down to 1% overheating in PHPP when no windows are opened but I'm still considering active cooling. Then something occurred to me - I've a big rainwater harvesting tank sitting out in the back garden as part of the build, up to 7,000 litres worth. Could I use that with a heat exchanger and the underfloor heating as Jeremy does with his ASHP? The only drawback is it will run down as the dry hot spell progresses. It's a big underground thermal store though otherwise.....hmmmm....

[Jeremy Harris]

Might well work OK, especially with the tank underground, as it will itself be cooled down to around 8 or 9 deg C by the surrounding ground.

[jack]

26 minutes ago, mike2016 said:

... up to 7,000 litres worth. 

 

What was the weather like in Dublin this year? Certainly in the southeast of England, by the time the hottest weather got here, we'd had many weeks without significant rain, and I would easily have gone through 7,000 litres of water just keeping the gardens alive.

[mike2016]

I'd 200 litres in a water butt during that dry spell and nearly finished that. Not a big gardener currently! That's the only problem with this approach, I'm using the rainwater storage when I need it most. But if I'm not gardening that much....could be a runner, otherwise I'll need ice, lots of ice!!