Hi all. I’m looking for some input on HVAC systems. We will be building a house this year and have been researching the different types of heating, cooling, and ventilation available. Some details on the house- 2700′ ranch, ICF walls in basement and main floor (about 1100′ of foundation will be crawlspace and 1600′ full basement – all ICF’s), r-50 cellulose in ceilings, low e, argon windows, about one third cathedral ceilings-11′, the balance 8′. 2″ rigid foam under basement slab.We are orienting the longest wall with the most glass facing south with 2′ overhangs. Garage is on the north. Plenty of trees for shading. The house is in south west Michigan – four definite seasons.
I would like to go geothermal with radiant heat (we will have all hard floor coverings) but I think this will break the bank ,especially when you add ac and the requisite ductwork. A boiler driven radiant system has also been discussed . A ducted geo system or a standard gas forced air are also options. The costs go up incredibly when you get into geo and radiant. I would like to do some or even most of the work myself, but it’s a scary endeavor ( at least the HVAC industry wants you to think that).I’m sure I’ll need some air management, HRV or ERV, filtration, maybe even dehumidification.
Have any of you folks had experience dealing with an ICF home in the upper midwest, and what types of systems have you found to be succesful? I’m sure that gas f/a will be more than adequate from a utilty bill standpoint, but we want to go that little extra bit if we can. This will be our own home, but we will market it as we build and probably sell in a couple of years. Has anyone out their put in their own system or parts thereof with one of the online companies that sells HVAC equipment? How are they with tech support?
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Hi, your project sounds vaugely familar. My wife and I are building an ICF home in western washington of similar configuation. Our house is 2100 sq ft with a full basement, ICF walls to the top. We decided on radiant heat after we got an estimate for an electric heat pump, $14000! We went with Radiantec in floor heat using an oil fired hot water tank. So far the installation hasn`t been very hard, we have done it ALL ourselves. We aren`t done yet though. Radiantec has a website with lots of information, very useful installation tips. Our system cost us a little over $7000 including the hot water heater. The Bock heater we chose was $2000, it heats 150 gallons of water an hour! Good luck with your project, I have some input on ICF houses if you`re interested.
I've actually looked at Radiantec's site. I will go back there. My first heat pump bid was $13,900 with about $4000 more for an Hrv and filtration.What are you doing for a.c.? What has been your expereince with ICF's?
We are foregoing A/C and relying on insulation and the cold water feature of our open direct system. We will be able to put cold water in the floor to help with cooling.
ICF construction is pretty fast, but includes some challenges that you may not have considered. Things like penetrations need to be carefully planned, dryer vents, electrical wires, (porch lights) plumbing penetrations, (outside faucets). Installing electrical outlets and switch boxes is more difficult, avoid plumbing on an outside wall, the styrofoam thickness on our ARXX system was 2 1/4 inches, that`s all the room you have to fit anything you want to put in the wall, plumbing vent pipe forinstance. Things like the electrical service panel, doesn`t fit on an outside wall without shimming the whole wall.
When you pour your footing, it`s important that it`s VERY flat. Take a modest 1/4 inch out of flat, stack perfectly level forms on it 8 or 9 feet high and you will see the angle at the top of the wall. You can brace the forms, but getting things exactly level plumb and square is a challenge. If I had it to do over I would have poured a layer of self-leveling thinset, like a tilesetter puts on a floor, on top of my footing so things were closer to perfect than you can make them with a trowel or screed.
Oh dear...I would steer clear of the claims made on the Radiantec site if I were you. Between the risk of Legionella infestations in open systems and the non-existant cooling effects of running a limited amount of cold water through the joists, I find their claims to fly in the face of logic and putting a lot of people at risk.The only radiant-cooling system that really works is the proven KARO system that naturalcooling.com is popularizing in the US. It consists of capillary tubes embedded in the ceiling that can heat and cool rooms. With a small dewpoint/temperature sensor, each cooling zone can shut off before the dewpoint is reached (i.e. someone opens a window on a hot, muggy day). Ergo, no risk of mold and other nasties.Radiant cooling systems still need some air movement and an AC coil to remove the latent heat. You could go mini-split, but I suspect that some smart thought going into combining a HRV/ERV system like the one from ultimateair.com with a small heating/cooling coil could do the trick in terms of providing comfortable humidity removal, supplemental heating/cooling, and relatively little internal room loss (ducting). Plus, it could serve as a source of supplemental heat for rooms that were put into setback.I have severe doubts that the water heater is either safe or appropriate for the role you are making it play. Water heaters are not designed as continually-running heating apliances and their life-span will suffer accordingly. Worse, if the right kind of temperature -protection is not invested in, your heater could suffer serious corrosion at the hands of flue gas condensation. This is particularly relevant in low-temp systems like radiant floor heating. Flue gas condensation not only puts the water heater at risk, it could cause enough corrosion to eat a hole into the chimney and poisen your family with CO. Instead of a water heater, I would invest in an oil boiler that is specifically made for the application you're using it for. In particular, the Viessmann Vitola series or the Monitor FCX come to mind. Neither has any issues with return water temperatures due to superior design. On the gas side, most condensing, modulating boilers will do a great job of saving you a lot of money as well, even when compared to the likes of the AWHG Polaris. Combiend with an indirect, a condensing, modulating boiler is hard to beat in terms of efficiency, low operating costs, longevity, etc. Naturally, such efficiency comes at a higher initial price.Lastly, I suggest you go to the Wall at HeatingHelp.com and search for posts on open-loop systems. In particular, Dave Yates has published a comprehensive analysis why open-loop systems are a very bad idea. I cannot emphasize enough the importance of taking a closer look at your system to ensure it won't kill you or your family. As a mere homeowner myself, I have no vested interest in this matter.
I recommend that you have a look at this web site, http://www.ecrtech.com. Perhaps you have only considered Waterfurnace. I don't see why the heated water option is so expensive for geothermal. It's just an extra heat exchanger and a small pump.
I imagine that desuperators will remain as expensive as they are until competition rears its head.I would love to see the larger manufacturers of split AC's offer desuperators as an option that can be built, tested, etc. as part of the OEM package. Hook up a glycolized loop and you're in business, with minimal maintenance, getting free hot water all summer long and inreasing the efficiency of the AC to boot. On the inside, have a dual-wall HX, two tiny pumps, a thermostat, and you're done...The current generation of retrofit desuperators (Trevor-Martin's Aquifier, for example) can be retrofit to GSHPs as well as regular ACs. In this capacity, they may be a viable alternative to the desuperators found in the Waterfurnace, ECR DX, etc.