Angelfire
Well-known member
Hiya Folks,
I had a load calc of my detached garage done a few years ago. Then got sent overseas for work and have now returned. My thoughts have turned back to getting this garage done so am dusting off the work I had done before. Anyway, ecomfort did a load calc on the space. I'll try to post a screenshot of what they provided. Ultimately, they indicated a 24k minisplit HP would suffice based on my area and the specs I provided them. This would be a 2 zone system with a 9k unit in one side of the garage and an 18k unit in the other (spec'ed out a 15k but those didn't seem to be available in the product line they were recommending). Anyway, I'm trying now to align their load calc with a different unit (everything they recommended was discontinued since the load calc was done) and am looking closer at cold weather performance which is where my knowledge of HVAC calculations is lacking. I'm in NM (Albuquerque) and while the winter temps aren't drastically cold, we do get the odd cold weather that drops into the single digits. While it is not essential to keep things toasty warm during this period, I am curious as to what I can expect from the units I'm looking at and here's where I'm asking for a little help. Attached is a chart showing the heating performance of a unit I'm considering and I'm really not sure how to read this and correlate it to the load calc. In the chart from the manufacturer, it indicates at an outside temperature of -4F and at an ambient of 70f indoors (DB), the btuh rating that is given is 15660. What confuses me about this is if the indoor temperature is higher, they indicate a smaller btuh number (ie. at 80F, the number has dropped to 15070 btuh). I had assumed this value was the value that the unit could produce at this outside temperature but given the input power is increasing as indoor temp rises, I am believing that the unit is working harder to meet the higher temps and hence it's overall output drops off a bit as the interior temp rises (probably a bad hypothesis by the way!). Also, I realize the load calc that was done was done for an outdoor temp of 18F....is there a way to step it back to say zero F and put a number on the btuh that is needed? I could do my own load calc on the building but was hoping there might be a simpler way of going about this.
Basically asking for any help to decipher what I'm looking at and whether or not this unit will keep the building somewhat warm at the lower temps. If it's easier, I'd be happy to send the full files via email or the like.
Thanking you experts in advance!
Cheers.
I had a load calc of my detached garage done a few years ago. Then got sent overseas for work and have now returned. My thoughts have turned back to getting this garage done so am dusting off the work I had done before. Anyway, ecomfort did a load calc on the space. I'll try to post a screenshot of what they provided. Ultimately, they indicated a 24k minisplit HP would suffice based on my area and the specs I provided them. This would be a 2 zone system with a 9k unit in one side of the garage and an 18k unit in the other (spec'ed out a 15k but those didn't seem to be available in the product line they were recommending). Anyway, I'm trying now to align their load calc with a different unit (everything they recommended was discontinued since the load calc was done) and am looking closer at cold weather performance which is where my knowledge of HVAC calculations is lacking. I'm in NM (Albuquerque) and while the winter temps aren't drastically cold, we do get the odd cold weather that drops into the single digits. While it is not essential to keep things toasty warm during this period, I am curious as to what I can expect from the units I'm looking at and here's where I'm asking for a little help. Attached is a chart showing the heating performance of a unit I'm considering and I'm really not sure how to read this and correlate it to the load calc. In the chart from the manufacturer, it indicates at an outside temperature of -4F and at an ambient of 70f indoors (DB), the btuh rating that is given is 15660. What confuses me about this is if the indoor temperature is higher, they indicate a smaller btuh number (ie. at 80F, the number has dropped to 15070 btuh). I had assumed this value was the value that the unit could produce at this outside temperature but given the input power is increasing as indoor temp rises, I am believing that the unit is working harder to meet the higher temps and hence it's overall output drops off a bit as the interior temp rises (probably a bad hypothesis by the way!). Also, I realize the load calc that was done was done for an outdoor temp of 18F....is there a way to step it back to say zero F and put a number on the btuh that is needed? I could do my own load calc on the building but was hoping there might be a simpler way of going about this.
Basically asking for any help to decipher what I'm looking at and whether or not this unit will keep the building somewhat warm at the lower temps. If it's easier, I'd be happy to send the full files via email or the like.
Thanking you experts in advance!
Cheers.
