Can pic related be done? And if it can, why can't I find anything about this being done? I want to avoid having to do a whole set of ductwork just for the ERV and keep it all contained in the basement.
>>2886942All this shit is basically just adding a heat exchanger to an air vent, if your place already has air vents then sure, just vent the return outside via a heat exchanger with a fresh intake.The whole 'fresh' air thing is bullshit though, these systems are only needed when you seal your house so much that there is zero natural ventilation so you get a moisture problem.The heat exchage is as bullshit; the same volume of air has to come in as go out, the temperature o both, at best, will be the average temperature of the two. Seriously consider if is worth doing for the cost of the exchanger. Cost rigt now eems to be only really viable for people who pay for the install by making a YouTube video about it
>>2886942You have to connect fresh air intake and exhaust both to the forced-air return, with some spacing. Pushing the hot air from the furnace straight out is very wasteful, even with a heat recovery unit. You could connect the fresh air intake both before and after the furnace, but it probably makes more sense to push it through the furnace and heat it, rather than mixing the hot air with the fresh, colder air.Like >>2886971 says, these things aren't really worth the investment, especially if you aren't in a very well sealed modern house. The heat energy they recover isn't very high compared to how much they cost to buy and install. It can be okay if you have serious moisture problems, then you have to choose one of the units that are specifically doing dehumidification, not just HERV.
>>2886942Why would you do this? Your current system is a closed loop cycle, the only outdoor air that comes in is from cracks around doors and windows and heat exchange already naturally happens there.
>>2886971i wrote this earlier and then spent all day looking at heat exchanger physics.i said they are at most 50% efficient because the flow is the same.for an ideal conductive heat exchanger that may be true, in practice a heat exchanger with thermal resistance between intake and output allows a temperature gradient to form across the exchanger which is how greater efficiencies are achieved.please excuse my earlier ignorance, good luck with your project, and thank you for the opportunity to look into this; i am certainly very interested in a diy project on this topic which im sure will fade quickly.
>>2886995>>2886971>>2886999>>2887107Thanks guysMy location is tropical, very hot and humid so it'll be an air conditioner; the plans I'm drawing up involve a completely sealed building envelop out of ICF so I'm worried about fresh air.I'm leaning to just do it by the book and have separate dedicated ducts for the ERV, since balancing air pressures on the intakes and exhausts will be very fucky requiring the two devices' fans to play nice with each other. But if someone can still convince me that >>2886942 this idea can still be done, I'd be very welcome to hear you out. >Unix philosophy, 1. Make each program do one thing well. To do a new job, build afresh rather than complicate old programs by adding new "features"
>>2886995why didnt I think of connecting them both to the forced air return lol, excuse me for missing this, I'm almost inebriated. Yeh, I'm getting one of those ERVs that can control humidity too >>2887414So fresh air gets injected into the forced-air return close to the AC. But regarding spacing, I'm imagining the only way to pull that off is to have the stale air ducts pull air close to the return vents at the rooms. Needs dedicated ducting, so we're back to square one with the original illustration in the OP. But we can at least have it suck air out of a major trunkline as far away as possible from the AC so less ductwork, filters, and holes in walls at least?
>>2886971>the temperature o both, at best, will be the average temperature of the two.That's only true for parallel flow. Using a counterflow heat exchanger, the fresh air can approach the original temperature of the outgoing warm air.
>>2887414The device could have an aspect ratio that lets it make use of the AC unit's pressure difference. As usual prices for a complete unit are far above the component costs.
