HRV With Integrated Zoning for Spot Bathroom Ventilation
MStaudaher
| Posted in General Questions on
Re: Aldes Vent Zone IAQ with heat recovery combined with zone register terminals. I was reading a GBA article that mentioned this HRV with integrated zoning for spot bathroom ventilation. Does anyone have any experience with thsi brand and this specific product? Is it a good HRV and does the zoning mechanism make reasonable sense to boost ventilation for specific bathrooms instead of simply boosting the ventilation rate for all baths?
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I'm hoping that a GBA reader who has installed this product can provide feedback.
It may also make sense to boost ventilation to bedrooms at night and turn it down/off during the day. Prices don't look too bad.
It should also be possible to use other ERVs with standard power zone dampers.
I called the company and spoke to one of their reps. Unfortunately the motors they use in their ERV/HRVs are PSC motors and not ECM motors. The reason that this individual control technology is apparently not offered by other manufacturers is because ALDES has a patent on it.
They sell the ZRT terminals separately, but it’s not clear to me if you could connect them to another brand of ERV/HRV to initiate a boost function when they are individually activated to increase spot ventilation in a bathroom.
The benefit of this type of system seems to be the fact that you could significantly increase ventilation to individual bathrooms on demand without having to increase return flow from all other returns simultaneously. You also wouldn’t need to have such a large ERV/HRV to obtain the needed increased flow to exhaust air from a particular location.
If anyone has wired one of these ZRT terminations to another HRV or ERV I would appreciate any information you could provide.
MStaudaher
Have you made any progress on this? I am planning to do the same type of install if I can solve the control issue. I won’t buy an ERV/HRV unless it has ECMs. Aldes sells the ZRTs with both 24 and 120 VAC wiring. The problem is that most ventilation systems don’t keep track of which switch called for boost. I bet a few relays could be used to trigger the correct zrt to open. Maybe just run a 4 wire Tstat wire from ventilator to switch and then a 2 wire from switch box to zrt. Put the relay on just before the ventilator which controls power to the extra 2 wires going back to the switch box and on to the zrt.
Depending on current draw of zrt you might be able to get it wired without dedicated power but I’d want to look at the specs on the ventilator and switch first.
I am moving forward. I am installing a Broan 250TE ERV and connecting it to the ZRT-2 terminals which will be located in the bathrooms and the laundry room. The HVAC contractor is using the 120V ZRT-2 terminals and is planing to control them with a relay.
Nice. That Broan 250 has some great stats. I am thinking about waiting for the fan tech hero ERVs to come out which should be in the next 10 months or so. I’ll go with the HRV if my humidity is uncontrollable this winter. I wish they had more units with swappable cores.
MStaudaher
I know it's been a while, but I am planning on doing almost the exact same installation you noted above. Looking back, is there anything you would have done differently, or did the 120V ZRT-2 terminals with relays work well with your Broan 250TE ERV?
Thanks,
Jordan
I’m still waiting for that Fantech hero erv which may never happen. I’ll probably go with the broan as well. I have all 4 of my 120v zrt’s installed and waiting. It’s great to be able to use any commercially available timer with these. The zrts have a micro switch that closes a circuit when the door swings open so it should be easy to control any erv or hrv as long as they have a boost control terminal. I already have my wiring in place as well as my ducting to the outside. Just need to build a plenum to combine the 4” ducts to 6”.
Good luck with your project. If you are installing a zrt in the attic make sure to insulate the heck out of it. I made a XPS box from 2” foam scraps that wraps around the zrt then used canned foam to get in all the tricky areas.
Don't assume ECM ERV will use less power than and PSC motor one. You need to look at the fan/power curve or table and see where you are at.
A Renewaire EV90/EV90P with PSC motors will use 46w at 90CFm, .25" static, while a Panasonic Intelli balance 100 will use at least 54w (and probably a bit more) under the same conditions.
A PSC motor ERV also doesn't need any control tie in to boost the exhaust (it may be unbalanced boost), just a drop in static from the zone damper opening. You do need to design the duct system to have it work correctly.
The downside of these flow regulators is that they have a .2" static requirement, which consumes some energy continuously when using an ECM motor.
MStaudaher, are you going to run "boost" in the laundry room? If you are not, you put a CAR-II in there.
Can anyone that installed an Aldes Vent Zone system provide an update on how it worked out? There's a lot of interest in this system but no experience reports on GBA yet.
Another option if you want to work with any ERV/HRV is to install motorized dampers in the bathrooms. To control the dampers you can use a smart switch, which will power a simple motorized damper like the Suncourt ZC206 or equivalent. The damper comes with a 24VAC transformer. When power is sent to the damper, it opens; no power springs the damper shut. There is a set screw to manually adjust how closed it will be in the closed position, so we can leave it partially open in the case of standard ventilation rates, and then when the occupant calls for boost mode the damper opens full blast while all the other bathroom dampers remain partially shut.
matthews25: thanks for the tip- the Suncourt damper could provide similar functionality. At $76 (Home Depot) that is significantly less expensive than ~$200 for Aldes (hvacquick). It also gives the option of restricting flow in a different location besides the exhaust itself- Aldes is built into a register- which limits its usage but also accounts for some of its increased cost.
The Aldes ZRT-2 minimal flow is adjustable to various increments between 10-30 CFM (4") or 10-6o (6"). The cheap Suncourt in theory can be adjusted to any setting, but in practice it will take installation time to understand what the actual CFM is and any changes to the system (like adding an additional exhaust) may require a re-balance of all the set screws. And the set screw mechanism would need to keep operating in its same set position over time. The damper would also need to be accessible (I think building codes sometimes require this), whereas an Aldes register is always going to be accessible.
I am a little concerned about power consumption in these systems for something that should only require power when switching positions. A Home Depot commenter mentioned that the Suncourt motor was hot, which might indicate wasted power. But not sure what to make of that and I don't know about Aldes. If the power consumption in the partially open position is close to zero, then the consumption in the open position may not matter that much since it is more infrequent.
If the switch in the bathroom is not on, no power should be going to the damper. And even when power is being sent, it is 24 Volts. Maybe the HD commenter did not have it wired correctly? I have not used it myself yet though.
As far as having access, you could install it in the bathroom ceiling above the register which might be hard to access or in another mechanical room closer to where the ERV is, like you mentioned. It would help if you have a flow hood to measure CFM. Ultimately you only need two settings: 1) Normal background ventilation rate where damper is slightly open (due to fixed set screw position) and 2) High spot-rate ventilation where damper is wide open.
I'm sure there are other cheaper dampers this was just the first one I found that looked promising online.