Standard Heat-Loss Values for Roof of an A-frame Greenhouse¹

Greenhouse Length in ft	Greenhouse Width in ft 5 6 8 10 11 13 15 18 20 23 26 29 32 50 72 Roof Loss in MBtu/hr2
5	7	8	9	10	11	12	12	13	14	15	16	17	18	22	26
10	14	16	18	19	21	23	25	27	28	30	32	34	35	45	54
20	28	32	35	39	42	46	50	53	57	60	64	67	71	88	106
30	42	48	53	58	64	69	74	80	85	90	96	101	106	133	160
40	57	64	71	78	85	92	99	106	113	142	151	159	168	177	212
50	71	80	89	97	106	115	124	133	142	151	159	168	177	222	266
60	85	96	106	117	127	138	149	159	170	181	191	202	212	265	318
70	99	112	124	136	149	161	173	186	198	211	223	235	248	310	372
80	113	127	142	156	170	184	198	212	227	241	255	269	283	354	424
90	127	143	159	175	191	207	223	239	255	271	287	303	319	398	478
100	142	159	177	195	212	230	248	266	283	301	319	336	354	443	532
200	283	319	354	390	425	460	496	531	567	602	637	673	708	885	1,062
300	425	478	531	584	637	690	743	797	850	903	956	1,009	1,062	1,328	1,594
400	566	637	708	779	850	920	991	1,062	1,133	1,204	1,274	1,345	1,416	1,770	2,124
500	708	797	885	974	1,062	1,150	1,239	1,328	1,417	1,505	1,593	1,682	1,770	2,213	2,666

¹Table adapted from:  Bohanon, H.R., C.E. Rahilly, and J. Stout. 1993. The greenhouse climate control handbook. Form C7S. Muskogee, OK: Acme Eng. and Manufacturing Corp.