Hello, I am shopping for the HRV in my new construction and would be interested in your opinion. I can have a standard HRV with a 71% SRE at 32faranheit that consumes 50W at low speed for 700$. Or I can get a high efficiency eko 1.5 with 83% SRE at 32 and 24W at low speed for 1500$. What do you think about those... I'm inclined to buy the cheaper HRV to save a bit of money but will stay in the house for a long time, so if it makes economic sense, I'll take the eko. thanks a lot! Alexis

Maybe you should look at what amount of owner maintenance is required of each one and what other features they offer. Not to mention track record. Cheap HRVs may have cheap components that barely make it past warranty.

Well, It depends....(just like everything else in life;)

Could you help us help you:
- Zip code
- Existing Heating and Cooling system (gas heat, electric resistance, mini split,...?)
- cost for said heat/ cooling sources? $/kwh, $/therm
- rated cfm delivered at low speed for both HRV's

Those all play a part in a financial comparison.

It will be a be a hard sell for the eko to save you more $ over a 10yr span then the 800$ upcharge. But ICFHybrid brings up the less quantifiable, but still significant, point that the budget HRV may be that way for a reason... If you have to replace the budget HRV just once, you lose all those $ savings.

All an HRV needs to do is meet ventilation needs which are usually pretty low. For example, my UltimateAir Recoupaerator delivers 190 cfm which is more than enough for a 6,000 sf home.

You may be able to get by with exhaust-only ventilation for a smaller home, or if your weather isn't so harsh.

Here are the stats:
st esprit, qc J0K 2L0
electric resistance heating
cost of electricity 7.78cent/kw

the home depot model ( nuair 145)low speed is 60cfm and makes 1.3cfm per watt
the eko 1.5 low speed is 40cfm and makes 2.5 cfm per watt.

I doubt the price upgrade for the eko is worth it...

Alexis

At your low electricity rates (compared to the average N. American price) there is not an operating cost finacial rationale for the higher efficiency HRV, especially since you are heating with resistance electricity. If the HRV is located inside of conditioned space, the heat from the motor heats the house at the same efficiency as your space heating.

There probably IS a financial rationale for heating at least one larger zone of your house with a ductless air source heat pump (mini-split), which will use a little more than half the amount of electricity for the heat delivered at outdoor temperatures between -15C & -25C, and even less at outdoor temperatures above -15C. The binned-hourly average temperature for January in St. Esprit is only -10C, and the three coldest month average is about -7C. A ductless heat pump in the largest zone could cut the annual heating power use of that zone by more than half.

Thanks for your awesome help, I'll get the nu-air hrv who is still energy star approved.
And yes, I have the intention to install a mini split, in the not too distant future.

At your wintertime low temperatures either the Mitsubishi "H2i Hyper Heating" series or Fujitsu's recently release Halcyon XLT-H series are the best choices:

http://smartgreenbuild.com/pdf/Fujitsu-RLS2H.pdf

http://www.mitsubishipro.com/media/226460/h2i_bro.pdf

Others will still work at those low temperatures, but don't have the design features for managing re-frozen defrost water etc that can become problems at sustained low temperatures. The H2i series will automatically stop at about -28C to self-protect, but are fully rated for operation at -25C, and will automatically re-start about -26C after an automatic shut-down. I'm not sure if the same is true for the XLT-H, but they're fully rated for operation at -26C.

I will add the mini split a year or two after the construction of the house ( trying to save a bit a money initially). The building is a double stud wall with cellulose insulation. I tought about installing a 2" pipe thru the wall ( well flashed on the exterior) and filling it with batt insulation so when I'll pu the mini split, it will be thru this pipe and will be well flashed and sealed with low expansion spray foam. Does this makes sense?

Dana1-

You said "If the HRV is located inside of conditioned space, the heat from the motor heats the house at the same efficiency as your space heating. "

It is not very important to your discussion here, but I have been trying to figure out what fraction of my electrical energy use stays inside the house and what fraction is external to the envelope. For my Venmar EKO 1.5, there are two fans located downstream of the heat exchanger, one for the fresh air and one for exhausting the stale air. The stale air duct from the HRV through the conditioned crawl space to the foundation exhaust is insulated. On low speed, the fans draw 13 W each, so not much, but I assume that the heat from the exhaust fan leaves the house with little heat exchange to the conditioned crawl space. So I would say that half the added electrical energy stays in the conditioned crawl space and half goes outside the envelope.

Alexis-

The motors in Venmar HRV's had a bad reputation (http://www.nlcpr.com/VenmarWarning.php) before they switched to the higher efficiency ECM (electronically commutated motors). I have not heard of problems with the new ECM motors, but I have not looked too thoroughly. It is hard to find out about this type of motor problem, but you might do what you can to see about reported problems before you make your purchase.

2" pipe thru the wall for minisplit.
Good idea. We ran the lines out without using a pipe an they were difficult to seal.

Posted By Bob I on 10 Sep 2013 02:37 PM
2" pipe thru the wall for minisplit.
Good idea. We ran the lines out without using a pipe an they were difficult to seal.

Most people use 3" PVC pipe, which makes it even easier to thread the cable & refrigerant lines through the same conduit. It's probably possible with 2" though.