There has been a great deal of threads and discussion on the GreenSpeed systems recently. I suggest you use the search function at the bottom of the main page and start reading these.

Also learn to use the AHRI HP Directory website.

IMO

This post was edited by tigerdunes on Wed, Aug 13, 14 at 12:23

Thanks Tigerdunes. Didn't know about the AHRI website but have since checked it out. I did have all of the SEER/EER/HSPF data. Have already looked at the threads posted on greenspeed but still can't get the two answers I'm hoping to learn.

1. Min outdoor average temp that greenspeed HP will still heat house at 100% without aux heater kicking in. (I did read the comments) Salemen are telling me it will heat house at really low outdoor temps closer to 1F but I read in the forums that I'm looking at 15F?

2. Electricity draw. I'm trying to figure out how to determine cost/benefit ratio of installing this HP and don't have any data to use for calculations.

Any help would be appreciated.

You should contact a dealer, request a load calculation, and ask for temp balance point for your home based on the size system the load calc indicates.

AHRI HP directory will give you the BTUs produced at 17 degrees.

Again dealer will need to provide the data on electricity draw for the condenser and air handler before the need for auxiliary heat strip demand to keep up.

IMO

Ah, was thinking that I should be able to find those figures myself.

Thank you Tigerdunes, I will ask the dealer for that info and see what they come up with.

Your question is difficult to answer. It depends about the heating load of your house and what your thermostat temperature setting.

Take a look at the product data sheet for the 4 ton size. The maximum heat output is flat at 48K BTUs until 18 degrees F. Then it starts to fall off. The balance point is probably between 8 and 18 degrees. It will be different during the day when the sun is out then it is in the middle of the night.

Post your electric rate and a calculation can be done on the operating cost of the HP versus an electric furnace.

Here is a link that might be useful: Greenspeed product data sheet

Mike,
My heating load was estimated by the salesman to be at 67,000 BTUH and cooling load to be at 29,500 BTUH.

Electric rate varies depending on the time of day.

On-peak daytime 6hrs 13.5 cents KWh
Mid-Peak daytime 6hrs 11.2 cents KWh
Off-Peak overnight 12 hrs 7.5 cents KWh

We normally keep our indoor temp lower to save costs around the 66 to 68F level because electric costs are so high here.
(Our utility provider also charges us another $120 per month for a delivery charge on top of the cost KWh but I don't need that value added into the calculation)

The heating and cooling loads seem a little lopsided. Did this salesman into all your house data into Manual J calculation software or was this a gross estimate based on area? Do you know what indoor and outdoor temperatures were used?

Your electric rates are low compared what I pay in NJ. The $120 delivery charge is a little ridiculous.

Salesman used an EMS Heat Loss/Gain Calculation form to provide the data to me.

Mike, you just clued me into something. I've just emailed the salesman to look into the winter outdoor temp he put into the heating load calculations. I think he may have made a mistake (too low temp outside) so I'm going to check that out and get back to you as soon as I have his response.

Just received a response from the salesman re outdoor winter temp.

He used Manual J calculation data and he says he used the temps recommended by HRAI because even if it doesn't get as cold that often, I still need to have the heating ability when it does.

He specified "Indoor winter temp 70F" "Outdoor winter temp -13F" (our actual avg winter outdoor temp is usually around 4F but it can go down to the -13F and even -20F a few times a winter in a very cold spell)

For summer - indoor temp was 76 and outdoor temp was 86.

Here are the design temperatures for the US and Canada. I am not good with Canada geography so look at page 24 and find the closest city to your location. The temperatures are supposed the be the average low, not the all time records.

I can see why your heating load is much greater than your cooling load. It gets a little nippy where you live.

The typical indoor design temperatures are 72 for winter and 75 for summer. You have to decide whether 70 and 76 are good for you. It is not going to make much difference for your cooling load, but I suspect it will have an impact on the heating load calculation.

Here is a link that might be useful: Outdoor Design Conditions

That was a great link. The outdoor winter temp for my area was listed as -8F. With respect to the indoor winter temp 70F is very adequate. We rarely heat above 68 anyway.

The -8F figure is not as low as the salesman put in at -13F for outdoor winter temp. I don't know if that difference will change my heating load though.

I can live with the summer temps he put in. The cooling load isn't an issue for me since the heating load is so much bigger.

Careful careful Jonesy - youâÂÂre dealing with contractors that are NOT at the top of theyâÂÂre game!

All their load calculations are being done to a standard - the American standard, which is the WRONG standard for Canada where you live.

The correct and latest version of the standard for Canada is the âÂÂCSA F280-12âÂÂ. However any CSA F280, such as the âÂÂCSA F280-M90â might suffice.

If youâÂÂre receiving government grants or rebates, provincial or federal, dependent on âÂÂproperâ load calculations, your application âÂÂmightâ be âÂÂDeniedâÂÂ, depending on who does the review, if the methodology you mentioned is used, as it does NOT conform to Canadian standards.

Just some friendly adviceâ¦

Good luck with finding someone that actually does it right - most people are CLUELESS and full of excuses!

Caveat Emptor!

IMPO

SR

Thank you for those insights SR. I didn't realize that the standard was that different for Canada. Out of 5 guys, so far the last salesman was the only one to even give me a heating/cooling load estimate. You are absolutely correct, the other 4 were clueless and so I am having another HVAC company come tomorrow for another quote.

Currently, there aren't any rebates or grants in Ontario for an ASHP unfortunately but it is still necessary that I know which size system to purchase for my home.

It looks like if I want an accurate heating load calculation, I'll have to take matters into my own hands. So if anyone has any ideas where I can get heat load calculating software for Canada or know someone who can do that online (trying to keep costs reasonable) I would be highly appreciative.