Heatpro-HP21404T TDH

johnm160

Well-known member
Jan 19, 2020
143
Orlando
Hi everyone,

I am trying to fill out my Simplified TDH for for my pool permit. I have not been able to find TDH specs on this heater online anywhere. I do not receive the heater until after I am applying for the permit. Does anyone know where I can find this spec?

Thanks
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
13,764
Pleasanton, CA
Welcome to the forum!

TDH is dependent on flow rate and flow rate is dependent on the pump's head curve and RPM. I don't think Hayward publishes the head loss curve for that particular model. However, I use a plumbing curve approximation for heat pumps:

Head Loss (ft) = 0.003 * GPM^2

There is no way for them to verify it anyway so you could probably use whatever you choose.

But shouldn't the PB be filling that out? They should be the one on the hook to do that.
 

JamesW

TFP Expert
Mar 2, 2011
21,091
With all of the new efficiency regulations, manufacturers pretty much have to provide this kind of information.

If necessary, you can use the curve from one of the other heat pump manufacturers as they should be similar.

Jandy, Pentair and Aquacal would be good places to start.
 

johnm160

Well-known member
Jan 19, 2020
143
Orlando
Humm I thought I replied to this a while ago. Haywood says they do not spec TDH for heatpumps and that is used for pumps. ?‍♂ I call BS but what can I say. I plugged in a low number, the form said for inspection i had to at LEAST be at what I put down. Higher is ok.