A Poll: ASHP Performance vs. Heating Degree Days

AC_Hacker · 04-08-12, 01:17 PM

It would be very useful to collect data from user's experience regarding ASHP performance and Heating Degree Day information, since their applicability is dependent on ambient air temps.

The poll should include:

Make and Model of Air Source Heat Pump
Heating Degree Days in your location
Percent of non-problematic performance during the heating season, estimated if necessary.
Comments

NOTE: A Heating Degree Data calculator can be FOUND HERE. For the sake of uniformity for comparison, we should go with Fahrenheit with the option to include Celsius in parenthesis. Go for Heating option, use 65F (18C) for base temp, breakdown = average. When the data file is available, the last line will have the yearly HDD average.

I'll go first,
1. Sanyo KHS0971 (9,000 BTU)
2. HDD = 4816 (2576)
3. 100%
4. No problems at all, the unit has worked without problem down to 17F

This should be very interesting...

-AC

Piwoslaw · 04-08-12, 01:56 PM

Shouldn't you also include data on the efficiency/COP depending on HDD? Something like kWh/HDD depending on HDD. I assume that at 17°F your Sanyo consumes more power to do the same amount of work than, say, at 55°F.

Also, wouldn't humidity have an effect on efficiency and/or potential problems? For example operation in around freezing temps will cause icing, etc., as humidity rises.

AC_Hacker · 04-08-12, 11:37 PM

Quote:

Originally Posted by Piwoslaw

Shouldn't you also include data on the efficiency/COP depending on HDD? Something like kWh/HDD depending on HDD. I assume that at 17°F your Sanyo consumes more power to do the same amount of work than, say, at 55°F.

Also, wouldn't humidity have an effect on efficiency and/or potential problems? For example operation in around freezing temps will cause icing, etc., as humidity rises.

Yes, for sure these thing matter a lot. What I'm actually after is acutal threshold of usefulness. What triggered it was a query by Daox about using an ASHP with water out (his HDD is about 7000, pretty chilly). The usefulness of an ASHP depends so much on ambient conditions like temperature and humidity, etc. I do know that the older units have a reputation for not working below 37F. I wonder if that's true. I wonder if Canadians are able to use them? I wonder if people in the upper midwest of the US can use them? I know that some folks think that everybody should have one... I'm not so sure about that.

I'm hoping to hear from others about their experiences.

-AC

04-08-12, 01:17 PM	#1
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	A Poll: ASHP Performance vs. Heating Degree Days It would be very useful to collect data from user's experience regarding ASHP performance and Heating Degree Day information, since their applicability is dependent on ambient air temps. The poll should include: Make and Model of Air Source Heat Pump Heating Degree Days in your location Percent of non-problematic performance during the heating season, estimated if necessary. Comments NOTE: A Heating Degree Data calculator can be FOUND HERE. For the sake of uniformity for comparison, we should go with Fahrenheit with the option to include Celsius in parenthesis. Go for Heating option, use 65F (18C) for base temp, breakdown = average. When the data file is available, the last line will have the yearly HDD average. I'll go first, 1. Sanyo KHS0971 (9,000 BTU) 2. HDD = 4816 (2576) 3. 100% 4. No problems at all, the unit has worked without problem down to 17F This should be very interesting... -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

04-08-12, 01:56 PM	#2
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Shouldn't you also include data on the efficiency/COP depending on HDD? Something like kWh/HDD depending on HDD. I assume that at 17°F your Sanyo consumes more power to do the same amount of work than, say, at 55°F. Also, wouldn't humidity have an effect on efficiency and/or potential problems? For example operation in around freezing temps will cause icing, etc., as humidity rises. __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.