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Decided to test how well my heat-recovery ventilation system works, put a sensor in a vent to see what the incoming air was. -Outdoor temp: -8 -Indoor temp: 19.5C -Incoming air temp: 8.3C So the heat recovery system manages to raise the temperature of the incoming air by 16 degrees C, using the exiting indoor air which was ~19C. I think that's pretty decent recovery of otherwise wasted heat.
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Dec 27, 2021 10:56
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| # ¿ May 3, 2024 21:18 |
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I actually did some calculations and the system is only around 60% efficient, that actually sucks. I should be getting around 80% I need to start fiddling with the vent settings in the rooms, think I got the incoming air flow too high.
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Dec 27, 2021 13:53
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I noticed last winter that my heat recovery ventilation system was only 60% efficient but it should be more like 80%+. I finally took a look at the attic and yeah, I guess the answer is pretty plain, insufficient insulation around the ducts. I am buying more insulation and wrapping around the ducts soon. I've been wondering if I should dig away and wrap the insulation all around the ducts, or if I should like get bigger mats and lay them over the ducts so that they and the area around is covered like a blanket. First time I ever looked in here. I thought I had a steel chimney tbh. It's made from some sort of cast masonry instead.  The silver wrapped duct is the kitchen exhaust, don't need to bother with that. His Divine Shadow fucked around with this message at 05:15 on Aug 17, 2022 |
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Aug 1, 2022 07:59
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I never thought about it, can't be aesthetic since nobody sees them. Strength perhaps, snow weight and all that.
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Aug 1, 2022 16:26
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devicenull posted:If it were me I'd just reinsulate the entire attic. It looks like you've got a good amount of space to work with, so just add another foot or so of blown-in to cover up the pipes (and the entire attic floor while you're at it). You could wrap the pipes more but that's going to be pretty minimal. You know, I didn't write about this because I was feeling pretty stressed out about it. After I went in and looked closer at the blown in insulation I found it was only 100mm or even that. I was flabbergasted, this house had less roof insulation than a british home (I read 200mm there) and it's been like this since 2014. This must be a mistake I thought, I went and looked at my house blueprints (I got the prints for everything, structure, water, ventilation, electrical etc) and double checked and yeah, I'm supposed to have 500mm of blown in insulation, not less than 100mm! Holy poo poo I've been living since 2014 with almost no insulation, I can't believe we haven't noticed it. The ducts are supposed to be buried in this stuff and not exposed at all. We have an annual consumption of 11,000 kWh, but that also includes direct electric heating in my shop so I figured that takes 2-3000 kWh on its own and 7-8000 kWh for the house and I thought that sounded OK since our house is electrically heated too, with a heat pump. I am kinda amazed how well it has worked despite all that. At any rate I contacted the company who built my house and showed them the photos and told them what I discovered, that was friday. They phoned me just now and apologized a lot and they will be sending a truck as soon as possible, inside two weeks and putting 500mm of blown in insulation in my attic. EDIT: went in and checked our electricity consumption for the last 12 months, 9850 kWh (!), impressive IMO. We did try and save power this year, lowered the indoor temps and used our accumulating masonry heater to get the temps up. It's gonna be interesting to see next year how much this lowers our consumption. I have a feeling we're gonna save a lot of money. I also have a feeling the building company knows that and are happy we're not trying to get them to pay for that.... His Divine Shadow fucked around with this message at 09:04 on Aug 8, 2022 |
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Aug 8, 2022 08:40
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My HVAC usage is soley for ventilation and is itself an energy conserver most of the year since it recovers the heat from indoor air. The house is so tight that without it running bad things happen, the first year we ran it on the lowest setting and got condensation issues indoors, need to be run at 2nd or higher setting. The funny thing is they did a FLIR scan when the house was new. I dunno how they missed that. But I think they mainly looked at the doors and windows.
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Aug 8, 2022 15:47
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devicenull posted:Good for you! And good that the builder is coming back after 8 years to fix this! Yeah got a call from the insulation company who will come this friday. I was nervous and in a hurry last week. I was worried maybe they'd be assholes about this and try and stiff me so I was thinking I had a long fight ahead of me. So I went bought a bunch of insulation last week (just 100 euros worth) for the pipes and wrapped them with an extra 100mm of fiberglass insulation, just incase. So I will have that 100mm of insulation around the pipes + blown in insulation on top. Should be really well insulated now. Winter's gonna be interesting... I already did some measurements and this morning it was 7C outside, checked the temps for outgoing and ingoing air post heat exchanger and it's 89% efficient now, what a jump from 60%
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Aug 9, 2022 11:28
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So that's what it used to look like: And after last night (promised last friday but there were problems with the blower)  Now that's looking more like what it should. Will be interesting once winter's here...
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Aug 17, 2022 05:18
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You'd have to dig it away basically in order to get at stuff and try and put it back later. But we can access the guts of our HRV unit from the mud room. It's just ducts up there, all the electronics are inside. It's also a super simple unit, rotary heat exchanger, belt drive, simple fans that I already changed the bearing in one fan on. Don't think blown in insulation gets much different with age unless it gets wet. It'll settle some.
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Aug 17, 2022 12:26
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I installed a mini split in my free standing garage, well I had a professional do it. 1700 euros installed (Mitsubishi Electric Ninja FT25). One of the better decisions I made, now I keep a constant 12 C in there which is warmer than I used to keep it and the power consumption has more than halved for the garage. I used to have direct electric oil filled radiators. Electricity prices this winter has been about 600% more expensive than usual so this thing has really saved some money... I have my garage well insulated for what it's worth.
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Jan 29, 2023 09:23
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Yooper posted:Geothermal heat pump in this case. I don't trust much the PO did (who had this installed) so I've been concerned it is undersized. Might not be, you have to consider a lot of things with ground source heat pumps. The pump might be sized correctly but the borehole or buried loop or whatever could be undersized or suboptimal. Or your settings for the pumps running are suboptimal in relation to the size of the loop or borehole and pump size. I fiddled a lot with the settings in mine and I reduced the amount of pointless starts by a lot from factory settings. I had the help of a forum of heat pump experts to guide me though. Dunno if there's anything like that in america. e: The above advice sounds basically like what I am talking about. ^^^^
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Mar 16, 2023 13:56
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That kind of setup is why my heat pump runs solely on an external sensor.
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Mar 17, 2023 15:31
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Yooper posted:So it keys off the remote sensor, so regardless what the woodstove room is doing the heat still functions as normal? Yeah, it goes by a temperature curve instead. And it works real well, the curve is also adjustable.
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Mar 17, 2023 16:52
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Nah, but we built our house 2013-14 and it's well insulated and tight. If the wind blows south south west it hits the sensor which probably helps. We have hydronic floor heating that heats an insulated floor slab.
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Mar 17, 2023 18:57
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I had to buy a chest freezer in a hurry when our freezer failed last week. Fastest/cheapest way was craigslist/facebook / equivalents. Got a 1980s 400 liter chest freezer, I have been looking it's energy consumption and it pulls about 180-200 watts when running, the thermostat didn't work so it wanted to go down to -31C, but it was just bad connection and after that it's hovering around -19 to -20.5 C and doing that it seems to use 1.6 kWh per day. Yearly energy consumption of 584 kWh, yeah its not very efficient, a modern one of a similar size probably pulls 300 kWh. I bet most of this is because the insulation has likely degraded and it was simply not made as thick as in a modern freezer. I think the compressor itself isn't much less efficient than a modern one. Anyway I thought it was interesting. I plan to put it outside later and see how it will work as a freezer in an unheated space, it used to sit like that so it should be fine. Wanna see how much power it uses then, if I'll keep it as a secondary freezer or turn it into a compost bin.
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Mar 24, 2023 09:25
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Once we decide on a new freezer it's going off-line again for the summer, I have a 100 liter chest freezer, it says it uses 170kWh per year and it's bought new in 2019. We shut it off and put everything in the big one. We're in no hurry now since electricity is no longer that insanely priced and this one has so much room. Trying to decide if we should still keep going with the stainless look or start moving over to classic white. I got this one hooked up to a wireless logger so I can see live if it's running and put in alarms if it goes offline.
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Mar 30, 2023 13:10
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I'll try and record a video of mine when it's running
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Apr 7, 2023 14:02
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Phone didn't want to upload it to imgur so I had to use youtube. I've never really touched the settings, just set it to maintain a base temp. I fiddled with the controls and tried to get the vanes to move and the fan to run as hard as it could. https://www.youtube.com/watch?v=CFhCM71Y4_4 Too bad the fan blowing into the microphone made a lot of noise, but at some points I manage to clear the air stream and you can hear pretty well the noise level of the machine and it's basically never this loud, just because I tried to make it loud. His Divine Shadow fucked around with this message at 14:30 on Apr 7, 2023 |
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Apr 7, 2023 14:27
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bootmanj posted:Anyone got experience with custom comfort heat pumps? Looking at a quote to change the house from oil to heatpumps but I can't really seem to find anything on the company. I don't know about that either, but I think this video I posted in the home thread is better suited here and probably very relevant to your interests if you are going to be dealing with HVAC companies trying to sell you heating solutions. https://www.youtube.com/watch?v=DTsQjiPlksA
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Mar 7, 2024 14:24
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Shifty Pony posted:He kind of touches on all of those, but he also blames many of the HVAC companies having dedicated sales staff, and the sales person isn't really incentivized to actually properly size the unit. The sales person doesn't want to scurry around the house estimating the actual thermal load they just want to get something in there as quick as possible, which means running a very basic calculation and then grabbing whatever the next size up that is in stock at their supplier. His point is oversizing a heat pump based system is bad and is not like oversizing a gas furnace system. You really wanna get a heat pump system that's properly sized for your needs to get the most efficiency out of it. Also cars have too much power nowadays too. And are too large by far.
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Mar 8, 2024 08:37
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If they've burst in the past it sounds like the basement needs heating (and perhaps better insulation) and the heat pump won't heat a space anywhere like an oil burner does (man they are sweet in that way, had a shower in the boiler room once, it was always so warm and nice). I think I would have radiators installed and let the heat pump heat the basement that way.
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Mar 9, 2024 19:17
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| # ¿ May 3, 2024 21:18 |
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I'd like a multimeter that could do a simultaneous amperage and voltage reading, showing both values in the display.
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Apr 5, 2024 16:02
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