This article explores the new macro designer and other new macro features available in Access 2010. After reading this article, you will be able to take full advantage of what Access 2010 macros have to offer.
Rules For Sizing Your Heat Pump Pool Heater. 1  Size at 4 BTUâs per gallon or 1 BTU per litre of water. To heat in normal summer conditions when ambient air temperature average 70Â°F in a 24 hour period.  Size at 5 BTUâs per gallon or 1.3 to 1.5 BTUâs per litre of water.
Here, 133,280 divided by 266,000 yields a heat-up time of .5 hours, or 30 minutes. Conversely, if the customer has a specific heating time in mind â say, 30 minutes â the formula works thusly: 133,280 Ã· .5 = 266,000 BTUs. In other words, a 400-gallon spa would need a heater with an output of 266,000 BTUs to heat the water in 30 minutes.